    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017package org.apache.commons.lang3;
    018
    019import java.lang.reflect.Method;
    020import java.lang.reflect.Modifier;
    021import java.util.ArrayList;
    022import java.util.Arrays;
    023import java.util.Collections;
    024import java.util.Comparator;
    025import java.util.HashMap;
    026import java.util.HashSet;
    027import java.util.Iterator;
    028import java.util.LinkedHashSet;
    029import java.util.List;
    030import java.util.Map;
    031import java.util.Objects;
    032import java.util.Set;
    033import java.util.stream.Collectors;
    034
    035import org.apache.commons.lang3.mutable.MutableObject;
    036
    037/**
    038 * Operates on classes without using reflection.
    039 *
    040 * <p>
    041 * This class handles invalid {@code null} inputs as best it can. Each method documents its behavior in more detail.
    042 * </p>
    043 *
    044 * <p>
    045 * The notion of a {@code canonical name} includes the human readable name for the type, for example {@code int[]}. The
    046 * non-canonical method variants work with the JVM names, such as {@code [I}.
    047 * </p>
    048 *
    049 * @since 2.0
    050 */
    051public class ClassUtils {
    052
    053    /**
    054     * Inclusivity literals for {@link #hierarchy(Class, Interfaces)}.
    055     *
    056     * @since 3.2
    057     */
    058    public enum Interfaces {
    059
    060        /** Includes interfaces. */
    061        INCLUDE,
    062
    063        /** Excludes interfaces. */
    064        EXCLUDE
    065    }
    066
    067    private static final Comparator<Class<?>> COMPARATOR = (o1, o2) -> Objects.compare(getName(o1), getName(o2), String::compareTo);
    068
    069    /**
    070     * The package separator character: {@code '&#x2e;' == {@value}}.
    071     */
    072    public static final char PACKAGE_SEPARATOR_CHAR = '.';
    073
    074    /**
    075     * The package separator String: {@code "&#x2e;"}.
    076     */
    077    public static final String PACKAGE_SEPARATOR = String.valueOf(PACKAGE_SEPARATOR_CHAR);
    078
    079    /**
    080     * The inner class separator character: {@code '$' == {@value}}.
    081     */
    082    public static final char INNER_CLASS_SEPARATOR_CHAR = '$';
    083
    084    /**
    085     * The inner class separator String: {@code "$"}.
    086     */
    087    public static final String INNER_CLASS_SEPARATOR = String.valueOf(INNER_CLASS_SEPARATOR_CHAR);
    088
    089    /**
    090     * Maps names of primitives to their corresponding primitive {@link Class}es.
    091     */
    092    private static final Map<String, Class<?>> namePrimitiveMap = new HashMap<>();
    093
    094    static {
    095        namePrimitiveMap.put("boolean", Boolean.TYPE);
    096        namePrimitiveMap.put("byte", Byte.TYPE);
    097        namePrimitiveMap.put("char", Character.TYPE);
    098        namePrimitiveMap.put("short", Short.TYPE);
    099        namePrimitiveMap.put("int", Integer.TYPE);
    100        namePrimitiveMap.put("long", Long.TYPE);
    101        namePrimitiveMap.put("double", Double.TYPE);
    102        namePrimitiveMap.put("float", Float.TYPE);
    103        namePrimitiveMap.put("void", Void.TYPE);
    104    }
    105
    106    /**
    107     * Maps primitive {@link Class}es to their corresponding wrapper {@link Class}.
    108     */
    109    private static final Map<Class<?>, Class<?>> primitiveWrapperMap = new HashMap<>();
    110
    111    static {
    112        primitiveWrapperMap.put(Boolean.TYPE, Boolean.class);
    113        primitiveWrapperMap.put(Byte.TYPE, Byte.class);
    114        primitiveWrapperMap.put(Character.TYPE, Character.class);
    115        primitiveWrapperMap.put(Short.TYPE, Short.class);
    116        primitiveWrapperMap.put(Integer.TYPE, Integer.class);
    117        primitiveWrapperMap.put(Long.TYPE, Long.class);
    118        primitiveWrapperMap.put(Double.TYPE, Double.class);
    119        primitiveWrapperMap.put(Float.TYPE, Float.class);
    120        primitiveWrapperMap.put(Void.TYPE, Void.TYPE);
    121    }
    122
    123    /**
    124     * Maps wrapper {@link Class}es to their corresponding primitive types.
    125     */
    126    private static final Map<Class<?>, Class<?>> wrapperPrimitiveMap = new HashMap<>();
    127
    128    static {
    129        primitiveWrapperMap.forEach((primitiveClass, wrapperClass) -> {
    130            if (!primitiveClass.equals(wrapperClass)) {
    131                wrapperPrimitiveMap.put(wrapperClass, primitiveClass);
    132            }
    133        });
    134    }
    135
    136    /**
    137     * Maps a primitive class name to its corresponding abbreviation used in array class names.
    138     */
    139    private static final Map<String, String> abbreviationMap;
    140
    141    /**
    142     * Maps an abbreviation used in array class names to corresponding primitive class name.
    143     */
    144    private static final Map<String, String> reverseAbbreviationMap;
    145
    146    /** Feed abbreviation maps. */
    147    static {
    148        final Map<String, String> map = new HashMap<>();
    149        map.put("int", "I");
    150        map.put("boolean", "Z");
    151        map.put("float", "F");
    152        map.put("long", "J");
    153        map.put("short", "S");
    154        map.put("byte", "B");
    155        map.put("double", "D");
    156        map.put("char", "C");
    157        abbreviationMap = Collections.unmodifiableMap(map);
    158        reverseAbbreviationMap = Collections.unmodifiableMap(map.entrySet().stream().collect(Collectors.toMap(Map.Entry::getValue, Map.Entry::getKey)));
    159    }
    160
    161    /**
    162     * Gets the class comparator, comparing by class name.
    163     *
    164     * @return the class comparator.
    165     * @since 3.13.0
    166     */
    167    public static Comparator<Class<?>> comparator() {
    168        return COMPARATOR;
    169    }
    170
    171    /**
    172     * Given a {@link List} of {@link Class} objects, this method converts them into class names.
    173     *
    174     * <p>
    175     * A new {@link List} is returned. {@code null} objects will be copied into the returned list as {@code null}.
    176     * </p>
    177     *
    178     * @param classes the classes to change
    179     * @return a {@link List} of class names corresponding to the Class objects, {@code null} if null input
    180     * @throws ClassCastException if {@code classes} contains a non-{@link Class} entry
    181     */
    182    public static List<String> convertClassesToClassNames(final List<Class<?>> classes) {
    183        return classes == null ? null : classes.stream().map(e -> getName(e, null)).collect(Collectors.toList());
    184    }
    185
    186    /**
    187     * Given a {@link List} of class names, this method converts them into classes.
    188     *
    189     * <p>
    190     * A new {@link List} is returned. If the class name cannot be found, {@code null} is stored in the {@link List}. If the
    191     * class name in the {@link List} is {@code null}, {@code null} is stored in the output {@link List}.
    192     * </p>
    193     *
    194     * @param classNames the classNames to change
    195     * @return a {@link List} of Class objects corresponding to the class names, {@code null} if null input
    196     * @throws ClassCastException if classNames contains a non String entry
    197     */
    198    public static List<Class<?>> convertClassNamesToClasses(final List<String> classNames) {
    199        if (classNames == null) {
    200            return null;
    201        }
    202        final List<Class<?>> classes = new ArrayList<>(classNames.size());
    203        classNames.forEach(className -> {
    204            try {
    205                classes.add(Class.forName(className));
    206            } catch (final Exception ex) {
    207                classes.add(null);
    208            }
    209        });
    210        return classes;
    211    }
    212
    213    /**
    214     * Gets the abbreviated name of a {@link Class}.
    215     *
    216     * @param cls the class to get the abbreviated name for, may be {@code null}
    217     * @param lengthHint the desired length of the abbreviated name
    218     * @return the abbreviated name or an empty string
    219     * @throws IllegalArgumentException if len &lt;= 0
    220     * @see #getAbbreviatedName(String, int)
    221     * @since 3.4
    222     */
    223    public static String getAbbreviatedName(final Class<?> cls, final int lengthHint) {
    224        if (cls == null) {
    225            return StringUtils.EMPTY;
    226        }
    227        return getAbbreviatedName(cls.getName(), lengthHint);
    228    }
    229
    230    /**
    231     * Gets the abbreviated class name from a {@link String}.
    232     *
    233     * <p>
    234     * The string passed in is assumed to be a class name - it is not checked.
    235     * </p>
    236     *
    237     * <p>
    238     * The abbreviation algorithm will shorten the class name, usually without significant loss of meaning.
    239     * </p>
    240     *
    241     * <p>
    242     * The abbreviated class name will always include the complete package hierarchy. If enough space is available,
    243     * rightmost sub-packages will be displayed in full length. The abbreviated package names will be shortened to a single
    244     * character.
    245     * </p>
    246     * <p>
    247     * Only package names are shortened, the class simple name remains untouched. (See examples.)
    248     * </p>
    249     * <p>
    250     * The result will be longer than the desired length only if all the package names shortened to a single character plus
    251     * the class simple name with the separating dots together are longer than the desired length. In other words, when the
    252     * class name cannot be shortened to the desired length.
    253     * </p>
    254     * <p>
    255     * If the class name can be shortened then the final length will be at most {@code lengthHint} characters.
    256     * </p>
    257     * <p>
    258     * If the {@code lengthHint} is zero or negative then the method throws exception. If you want to achieve the shortest
    259     * possible version then use {@code 1} as a {@code lengthHint}.
    260     * </p>
    261     *
    262     * <table>
    263     * <caption>Examples</caption>
    264     * <tr>
    265     * <td>className</td>
    266     * <td>len</td>
    267     * <td>return</td>
    268     * </tr>
    269     * <tr>
    270     * <td>null</td>
    271     * <td>1</td>
    272     * <td>""</td>
    273     * </tr>
    274     * <tr>
    275     * <td>"java.lang.String"</td>
    276     * <td>5</td>
    277     * <td>"j.l.String"</td>
    278     * </tr>
    279     * <tr>
    280     * <td>"java.lang.String"</td>
    281     * <td>15</td>
    282     * <td>"j.lang.String"</td>
    283     * </tr>
    284     * <tr>
    285     * <td>"java.lang.String"</td>
    286     * <td>30</td>
    287     * <td>"java.lang.String"</td>
    288     * </tr>
    289     * <tr>
    290     * <td>"org.apache.commons.lang3.ClassUtils"</td>
    291     * <td>18</td>
    292     * <td>"o.a.c.l.ClassUtils"</td>
    293     * </tr>
    294     * </table>
    295     *
    296     * @param className the className to get the abbreviated name for, may be {@code null}
    297     * @param lengthHint the desired length of the abbreviated name
    298     * @return the abbreviated name or an empty string if the specified class name is {@code null} or empty string. The
    299     *         abbreviated name may be longer than the desired length if it cannot be abbreviated to the desired length.
    300     * @throws IllegalArgumentException if {@code len <= 0}
    301     * @since 3.4
    302     */
    303    public static String getAbbreviatedName(final String className, final int lengthHint) {
    304        if (lengthHint <= 0) {
    305            throw new IllegalArgumentException("len must be > 0");
    306        }
    307        if (className == null) {
    308            return StringUtils.EMPTY;
    309        }
    310        if (className.length() <= lengthHint) {
    311            return className;
    312        }
    313        final char[] abbreviated = className.toCharArray();
    314        int target = 0;
    315        int source = 0;
    316        while (source < abbreviated.length) {
    317            // copy the next part
    318            int runAheadTarget = target;
    319            while (source < abbreviated.length && abbreviated[source] != '.') {
    320                abbreviated[runAheadTarget++] = abbreviated[source++];
    321            }
    322
    323            ++target;
    324            if (useFull(runAheadTarget, source, abbreviated.length, lengthHint) || target > runAheadTarget) {
    325                target = runAheadTarget;
    326            }
    327
    328            // copy the '.' unless it was the last part
    329            if (source < abbreviated.length) {
    330                abbreviated[target++] = abbreviated[source++];
    331            }
    332        }
    333        return new String(abbreviated, 0, target);
    334    }
    335
    336    /**
    337     * Gets a {@link List} of all interfaces implemented by the given class and its superclasses.
    338     *
    339     * <p>
    340     * The order is determined by looking through each interface in turn as declared in the source file and following its
    341     * hierarchy up. Then each superclass is considered in the same way. Later duplicates are ignored, so the order is
    342     * maintained.
    343     * </p>
    344     *
    345     * @param cls the class to look up, may be {@code null}
    346     * @return the {@link List} of interfaces in order, {@code null} if null input
    347     */
    348    public static List<Class<?>> getAllInterfaces(final Class<?> cls) {
    349        if (cls == null) {
    350            return null;
    351        }
    352
    353        final LinkedHashSet<Class<?>> interfacesFound = new LinkedHashSet<>();
    354        getAllInterfaces(cls, interfacesFound);
    355
    356        return new ArrayList<>(interfacesFound);
    357    }
    358
    359    /**
    360     * Gets the interfaces for the specified class.
    361     *
    362     * @param cls the class to look up, may be {@code null}
    363     * @param interfacesFound the {@link Set} of interfaces for the class
    364     */
    365    private static void getAllInterfaces(Class<?> cls, final HashSet<Class<?>> interfacesFound) {
    366        while (cls != null) {
    367            final Class<?>[] interfaces = cls.getInterfaces();
    368
    369            for (final Class<?> i : interfaces) {
    370                if (interfacesFound.add(i)) {
    371                    getAllInterfaces(i, interfacesFound);
    372                }
    373            }
    374
    375            cls = cls.getSuperclass();
    376        }
    377    }
    378
    379    /**
    380     * Gets a {@link List} of superclasses for the given class.
    381     *
    382     * @param cls the class to look up, may be {@code null}
    383     * @return the {@link List} of superclasses in order going up from this one {@code null} if null input
    384     */
    385    public static List<Class<?>> getAllSuperclasses(final Class<?> cls) {
    386        if (cls == null) {
    387            return null;
    388        }
    389        final List<Class<?>> classes = new ArrayList<>();
    390        Class<?> superclass = cls.getSuperclass();
    391        while (superclass != null) {
    392            classes.add(superclass);
    393            superclass = superclass.getSuperclass();
    394        }
    395        return classes;
    396    }
    397
    398    /**
    399     * Gets the canonical class name for a {@link Class}.
    400     *
    401     * @param cls the class for which to get the canonical class name; may be null
    402     * @return the canonical name of the class, or the empty String
    403     * @since 3.7
    404     * @see Class#getCanonicalName()
    405     */
    406    public static String getCanonicalName(final Class<?> cls) {
    407        return getCanonicalName(cls, StringUtils.EMPTY);
    408    }
    409
    410    /**
    411     * Gets the canonical name for a {@link Class}.
    412     *
    413     * @param cls the class for which to get the canonical class name; may be null
    414     * @param valueIfNull the return value if null
    415     * @return the canonical name of the class, or {@code valueIfNull}
    416     * @since 3.7
    417     * @see Class#getCanonicalName()
    418     */
    419    public static String getCanonicalName(final Class<?> cls, final String valueIfNull) {
    420        if (cls == null) {
    421            return valueIfNull;
    422        }
    423        final String canonicalName = cls.getCanonicalName();
    424        return canonicalName == null ? valueIfNull : canonicalName;
    425    }
    426
    427    /**
    428     * Gets the canonical name for an {@link Object}.
    429     *
    430     * @param object the object for which to get the canonical class name; may be null
    431     * @return the canonical name of the object, or the empty String
    432     * @since 3.7
    433     * @see Class#getCanonicalName()
    434     */
    435    public static String getCanonicalName(final Object object) {
    436        return getCanonicalName(object, StringUtils.EMPTY);
    437    }
    438
    439    /**
    440     * Gets the canonical name for an {@link Object}.
    441     *
    442     * @param object the object for which to get the canonical class name; may be null
    443     * @param valueIfNull the return value if null
    444     * @return the canonical name of the object or {@code valueIfNull}
    445     * @since 3.7
    446     * @see Class#getCanonicalName()
    447     */
    448    public static String getCanonicalName(final Object object, final String valueIfNull) {
    449        if (object == null) {
    450            return valueIfNull;
    451        }
    452        final String canonicalName = object.getClass().getCanonicalName();
    453        return canonicalName == null ? valueIfNull : canonicalName;
    454    }
    455
    456    /**
    457     * Converts a given name of class into canonical format. If name of class is not a name of array class it returns
    458     * unchanged name.
    459     *
    460     * <p>
    461     * The method does not change the {@code $} separators in case the class is inner class.
    462     * </p>
    463     *
    464     * <p>
    465     * Example:
    466     * <ul>
    467     * <li>{@code getCanonicalName("[I") = "int[]"}</li>
    468     * <li>{@code getCanonicalName("[Ljava.lang.String;") = "java.lang.String[]"}</li>
    469     * <li>{@code getCanonicalName("java.lang.String") = "java.lang.String"}</li>
    470     * </ul>
    471     * </p>
    472     *
    473     * @param className the name of class
    474     * @return canonical form of class name
    475     * @since 2.4
    476     */
    477    private static String getCanonicalName(String className) {
    478        className = StringUtils.deleteWhitespace(className);
    479        if (className == null) {
    480            return null;
    481        }
    482        int dim = 0;
    483        while (className.startsWith("[")) {
    484            dim++;
    485            className = className.substring(1);
    486        }
    487        if (dim < 1) {
    488            return className;
    489        }
    490        if (className.startsWith("L")) {
    491            className = className.substring(1, className.endsWith(";") ? className.length() - 1 : className.length());
    492        } else if (!className.isEmpty()) {
    493            className = reverseAbbreviationMap.get(className.substring(0, 1));
    494        }
    495        final StringBuilder canonicalClassNameBuffer = new StringBuilder(className);
    496        for (int i = 0; i < dim; i++) {
    497            canonicalClassNameBuffer.append("[]");
    498        }
    499        return canonicalClassNameBuffer.toString();
    500    }
    501
    502    /**
    503     * Returns the (initialized) class represented by {@code className} using the {@code classLoader}. This implementation
    504     * supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    505     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    506     *
    507     * @param classLoader the class loader to use to load the class
    508     * @param className the class name
    509     * @return the class represented by {@code className} using the {@code classLoader}
    510     * @throws NullPointerException if the className is null
    511     * @throws ClassNotFoundException if the class is not found
    512     */
    513    public static Class<?> getClass(final ClassLoader classLoader, final String className) throws ClassNotFoundException {
    514        return getClass(classLoader, className, true);
    515    }
    516
    517    /**
    518     * Returns the class represented by {@code className} using the {@code classLoader}. This implementation supports the
    519     * syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}", "{@code [Ljava.util.Map.Entry;}", and
    520     * "{@code [Ljava.util.Map$Entry;}".
    521     *
    522     * @param classLoader the class loader to use to load the class
    523     * @param className the class name
    524     * @param initialize whether the class must be initialized
    525     * @return the class represented by {@code className} using the {@code classLoader}
    526     * @throws NullPointerException if the className is null
    527     * @throws ClassNotFoundException if the class is not found
    528     */
    529    public static Class<?> getClass(final ClassLoader classLoader, final String className, final boolean initialize) throws ClassNotFoundException {
    530        try {
    531            Class<?> clazz = namePrimitiveMap.get(className);
    532            return clazz != null ? clazz : Class.forName(toCanonicalName(className), initialize, classLoader);
    533        } catch (final ClassNotFoundException ex) {
    534            // allow path separators (.) as inner class name separators
    535            final int lastDotIndex = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    536
    537            if (lastDotIndex != -1) {
    538                try {
    539                    return getClass(classLoader, className.substring(0, lastDotIndex) + INNER_CLASS_SEPARATOR_CHAR + className.substring(lastDotIndex + 1),
    540                        initialize);
    541                } catch (final ClassNotFoundException ignored) {
    542                    // ignore exception
    543                }
    544            }
    545
    546            throw ex;
    547        }
    548    }
    549
    550    /**
    551     * Returns the (initialized) class represented by {@code className} using the current thread's context class loader.
    552     * This implementation supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    553     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    554     *
    555     * @param className the class name
    556     * @return the class represented by {@code className} using the current thread's context class loader
    557     * @throws NullPointerException if the className is null
    558     * @throws ClassNotFoundException if the class is not found
    559     */
    560    public static Class<?> getClass(final String className) throws ClassNotFoundException {
    561        return getClass(className, true);
    562    }
    563
    564    /**
    565     * Returns the class represented by {@code className} using the current thread's context class loader. This
    566     * implementation supports the syntaxes "{@code java.util.Map.Entry[]}", "{@code java.util.Map$Entry[]}",
    567     * "{@code [Ljava.util.Map.Entry;}", and "{@code [Ljava.util.Map$Entry;}".
    568     *
    569     * @param className the class name
    570     * @param initialize whether the class must be initialized
    571     * @return the class represented by {@code className} using the current thread's context class loader
    572     * @throws NullPointerException if the className is null
    573     * @throws ClassNotFoundException if the class is not found
    574     */
    575    public static Class<?> getClass(final String className, final boolean initialize) throws ClassNotFoundException {
    576        final ClassLoader contextCL = Thread.currentThread().getContextClassLoader();
    577        final ClassLoader loader = contextCL == null ? ClassUtils.class.getClassLoader() : contextCL;
    578        return getClass(loader, className, initialize);
    579    }
    580
    581    /**
    582     * Delegates to {@link Class#getComponentType()} using generics.
    583     *
    584     * @param <T> The array class type.
    585     * @param cls A class or null.
    586     * @return The array component type or null.
    587     * @see Class#getComponentType()
    588     * @since 3.13.0
    589     */
    590    @SuppressWarnings("unchecked")
    591    public static <T> Class<T> getComponentType(final Class<T[]> cls) {
    592        return cls == null ? null : (Class<T>) cls.getComponentType();
    593    }
    594
    595    /**
    596     * Null-safe version of {@code cls.getName()}
    597     *
    598     * @param cls the class for which to get the class name; may be null
    599     * @return the class name or the empty string in case the argument is {@code null}
    600     * @since 3.7
    601     * @see Class#getSimpleName()
    602     */
    603    public static String getName(final Class<?> cls) {
    604        return getName(cls, StringUtils.EMPTY);
    605    }
    606
    607    /**
    608     * Null-safe version of {@code cls.getName()}
    609     *
    610     * @param cls the class for which to get the class name; may be null
    611     * @param valueIfNull the return value if the argument {@code cls} is {@code null}
    612     * @return the class name or {@code valueIfNull}
    613     * @since 3.7
    614     * @see Class#getName()
    615     */
    616    public static String getName(final Class<?> cls, final String valueIfNull) {
    617        return cls == null ? valueIfNull : cls.getName();
    618    }
    619
    620    /**
    621     * Null-safe version of {@code object.getClass().getName()}
    622     *
    623     * @param object the object for which to get the class name; may be null
    624     * @return the class name or the empty String
    625     * @since 3.7
    626     * @see Class#getSimpleName()
    627     */
    628    public static String getName(final Object object) {
    629        return getName(object, StringUtils.EMPTY);
    630    }
    631
    632    /**
    633     * Null-safe version of {@code object.getClass().getSimpleName()}
    634     *
    635     * @param object the object for which to get the class name; may be null
    636     * @param valueIfNull the value to return if {@code object} is {@code null}
    637     * @return the class name or {@code valueIfNull}
    638     * @since 3.0
    639     * @see Class#getName()
    640     */
    641    public static String getName(final Object object, final String valueIfNull) {
    642        return object == null ? valueIfNull : object.getClass().getName();
    643    }
    644
    645    /**
    646     * Gets the package name from the canonical name of a {@link Class}.
    647     *
    648     * @param cls the class to get the package name for, may be {@code null}.
    649     * @return the package name or an empty string
    650     * @since 2.4
    651     */
    652    public static String getPackageCanonicalName(final Class<?> cls) {
    653        if (cls == null) {
    654            return StringUtils.EMPTY;
    655        }
    656        return getPackageCanonicalName(cls.getName());
    657    }
    658
    659    /**
    660     * Gets the package name from the class name of an {@link Object}.
    661     *
    662     * @param object the class to get the package name for, may be null
    663     * @param valueIfNull the value to return if null
    664     * @return the package name of the object, or the null value
    665     * @since 2.4
    666     */
    667    public static String getPackageCanonicalName(final Object object, final String valueIfNull) {
    668        if (object == null) {
    669            return valueIfNull;
    670        }
    671        return getPackageCanonicalName(object.getClass().getName());
    672    }
    673
    674    /**
    675     * Gets the package name from the class name.
    676     *
    677     * <p>
    678     * The string passed in is assumed to be a class name - it is not checked.
    679     * </p>
    680     * <p>
    681     * If the class is in the default package, return an empty string.
    682     * </p>
    683     *
    684     * @param name the name to get the package name for, may be {@code null}
    685     * @return the package name or an empty string
    686     * @since 2.4
    687     */
    688    public static String getPackageCanonicalName(final String name) {
    689        return getPackageName(getCanonicalName(name));
    690    }
    691
    692    /**
    693     * Gets the package name of a {@link Class}.
    694     *
    695     * @param cls the class to get the package name for, may be {@code null}.
    696     * @return the package name or an empty string
    697     */
    698    public static String getPackageName(final Class<?> cls) {
    699        if (cls == null) {
    700            return StringUtils.EMPTY;
    701        }
    702        return getPackageName(cls.getName());
    703    }
    704
    705    /**
    706     * Gets the package name of an {@link Object}.
    707     *
    708     * @param object the class to get the package name for, may be null
    709     * @param valueIfNull the value to return if null
    710     * @return the package name of the object, or the null value
    711     */
    712    public static String getPackageName(final Object object, final String valueIfNull) {
    713        if (object == null) {
    714            return valueIfNull;
    715        }
    716        return getPackageName(object.getClass());
    717    }
    718
    719    /**
    720     * Gets the package name from a {@link String}.
    721     *
    722     * <p>
    723     * The string passed in is assumed to be a class name - it is not checked.
    724     * </p>
    725     * <p>
    726     * If the class is unpackaged, return an empty string.
    727     * </p>
    728     *
    729     * @param className the className to get the package name for, may be {@code null}
    730     * @return the package name or an empty string
    731     */
    732    public static String getPackageName(String className) {
    733        if (StringUtils.isEmpty(className)) {
    734            return StringUtils.EMPTY;
    735        }
    736
    737        // Strip array encoding
    738        while (className.charAt(0) == '[') {
    739            className = className.substring(1);
    740        }
    741        // Strip Object type encoding
    742        if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
    743            className = className.substring(1);
    744        }
    745
    746        final int i = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    747        if (i == -1) {
    748            return StringUtils.EMPTY;
    749        }
    750        return className.substring(0, i);
    751    }
    752
    753    /**
    754     * Returns the desired Method much like {@code Class.getMethod}, however it ensures that the returned Method is from a
    755     * public class or interface and not from an anonymous inner class. This means that the Method is invokable and doesn't
    756     * fall foul of Java bug <a href="https://bugs.java.com/bugdatabase/view_bug.do?bug_id=4071957">4071957</a>).
    757     *
    758     * <pre>
    759     *  <code>Set set = Collections.unmodifiableSet(...);
    760     *  Method method = ClassUtils.getPublicMethod(set.getClass(), "isEmpty",  new Class[0]);
    761     *  Object result = method.invoke(set, new Object[]);</code>
    762     * </pre>
    763     *
    764     * @param cls the class to check, not null
    765     * @param methodName the name of the method
    766     * @param parameterTypes the list of parameters
    767     * @return the method
    768     * @throws NullPointerException if the class is null
    769     * @throws SecurityException if a security violation occurred
    770     * @throws NoSuchMethodException if the method is not found in the given class or if the method doesn't conform with the
    771     *         requirements
    772     */
    773    public static Method getPublicMethod(final Class<?> cls, final String methodName, final Class<?>... parameterTypes) throws NoSuchMethodException {
    774
    775        final Method declaredMethod = cls.getMethod(methodName, parameterTypes);
    776        if (isPublic(declaredMethod.getDeclaringClass())) {
    777            return declaredMethod;
    778        }
    779
    780        final List<Class<?>> candidateClasses = new ArrayList<>(getAllInterfaces(cls));
    781        candidateClasses.addAll(getAllSuperclasses(cls));
    782
    783        for (final Class<?> candidateClass : candidateClasses) {
    784            if (!isPublic(candidateClass)) {
    785                continue;
    786            }
    787            final Method candidateMethod;
    788            try {
    789                candidateMethod = candidateClass.getMethod(methodName, parameterTypes);
    790            } catch (final NoSuchMethodException ex) {
    791                continue;
    792            }
    793            if (Modifier.isPublic(candidateMethod.getDeclaringClass().getModifiers())) {
    794                return candidateMethod;
    795            }
    796        }
    797
    798        throw new NoSuchMethodException("Can't find a public method for " + methodName + " " + ArrayUtils.toString(parameterTypes));
    799    }
    800
    801    /**
    802     * Gets the canonical name minus the package name from a {@link Class}.
    803     *
    804     * @param cls the class for which to get the short canonical class name; may be null
    805     * @return the canonical name without the package name or an empty string
    806     * @since 2.4
    807     * @see Class#getCanonicalName()
    808     */
    809    public static String getShortCanonicalName(final Class<?> cls) {
    810        return cls == null ? StringUtils.EMPTY : getShortCanonicalName(cls.getCanonicalName());
    811    }
    812
    813    /**
    814     * Gets the canonical name minus the package name for an {@link Object}.
    815     *
    816     * @param object the class to get the short name for, may be null
    817     * @param valueIfNull the value to return if null
    818     * @return the canonical name of the object without the package name, or the null value
    819     * @since 2.4
    820     * @see Class#getCanonicalName()
    821     */
    822    public static String getShortCanonicalName(final Object object, final String valueIfNull) {
    823        return object == null ? valueIfNull : getShortCanonicalName(object.getClass().getCanonicalName());
    824    }
    825
    826    /**
    827     * Gets the canonical name minus the package name from a String.
    828     *
    829     * <p>
    830     * The string passed in is assumed to be a class name - it is not checked.
    831     * </p>
    832     *
    833     * <p>
    834     * Note that this method is mainly designed to handle the arrays and primitives properly. If the class is an inner class
    835     * then the result value will not contain the outer classes. This way the behavior of this method is different from
    836     * {@link #getShortClassName(String)}. The argument in that case is class name and not canonical name and the return
    837     * value retains the outer classes.
    838     * </p>
    839     *
    840     * <p>
    841     * Note that there is no way to reliably identify the part of the string representing the package hierarchy and the part
    842     * that is the outer class or classes in case of an inner class. Trying to find the class would require reflective call
    843     * and the class itself may not even be on the class path. Relying on the fact that class names start with capital
    844     * letter and packages with lower case is heuristic.
    845     * </p>
    846     *
    847     * <p>
    848     * It is recommended to use {@link #getShortClassName(String)} for cases when the class is an inner class and use this
    849     * method for cases it is designed for.
    850     * </p>
    851     *
    852     * <table>
    853     * <caption>Examples</caption>
    854     * <tr>
    855     * <td>return value</td>
    856     * <td>input</td>
    857     * </tr>
    858     * <tr>
    859     * <td>{@code ""}</td>
    860     * <td>{@code (String)null}</td>
    861     * </tr>
    862     * <tr>
    863     * <td>{@code "Map.Entry"}</td>
    864     * <td>{@code java.util.Map.Entry.class.getName()}</td>
    865     * </tr>
    866     * <tr>
    867     * <td>{@code "Entry"}</td>
    868     * <td>{@code java.util.Map.Entry.class.getCanonicalName()}</td>
    869     * </tr>
    870     * <tr>
    871     * <td>{@code "ClassUtils"}</td>
    872     * <td>{@code "org.apache.commons.lang3.ClassUtils"}</td>
    873     * </tr>
    874     * <tr>
    875     * <td>{@code "ClassUtils[]"}</td>
    876     * <td>{@code "[Lorg.apache.commons.lang3.ClassUtils;"}</td>
    877     * </tr>
    878     * <tr>
    879     * <td>{@code "ClassUtils[][]"}</td>
    880     * <td>{@code "[[Lorg.apache.commons.lang3.ClassUtils;"}</td>
    881     * </tr>
    882     * <tr>
    883     * <td>{@code "ClassUtils[]"}</td>
    884     * <td>{@code "org.apache.commons.lang3.ClassUtils[]"}</td>
    885     * </tr>
    886     * <tr>
    887     * <td>{@code "ClassUtils[][]"}</td>
    888     * <td>{@code "org.apache.commons.lang3.ClassUtils[][]"}</td>
    889     * </tr>
    890     * <tr>
    891     * <td>{@code "int[]"}</td>
    892     * <td>{@code "[I"}</td>
    893     * </tr>
    894     * <tr>
    895     * <td>{@code "int[]"}</td>
    896     * <td>{@code int[].class.getCanonicalName()}</td>
    897     * </tr>
    898     * <tr>
    899     * <td>{@code "int[]"}</td>
    900     * <td>{@code int[].class.getName()}</td>
    901     * </tr>
    902     * <tr>
    903     * <td>{@code "int[][]"}</td>
    904     * <td>{@code "[[I"}</td>
    905     * </tr>
    906     * <tr>
    907     * <td>{@code "int[]"}</td>
    908     * <td>{@code "int[]"}</td>
    909     * </tr>
    910     * <tr>
    911     * <td>{@code "int[][]"}</td>
    912     * <td>{@code "int[][]"}</td>
    913     * </tr>
    914     * </table>
    915     *
    916     * @param canonicalName the class name to get the short name for
    917     * @return the canonical name of the class without the package name or an empty string
    918     * @since 2.4
    919     */
    920    public static String getShortCanonicalName(final String canonicalName) {
    921        return getShortClassName(getCanonicalName(canonicalName));
    922    }
    923
    924    /**
    925     * Gets the class name minus the package name from a {@link Class}.
    926     *
    927     * <p>
    928     * This method simply gets the name using {@code Class.getName()} and then calls {@link #getShortClassName(Class)}. See
    929     * relevant notes there.
    930     * </p>
    931     *
    932     * @param cls the class to get the short name for.
    933     * @return the class name without the package name or an empty string. If the class is an inner class then the returned
    934     *         value will contain the outer class or classes separated with {@code .} (dot) character.
    935     */
    936    public static String getShortClassName(final Class<?> cls) {
    937        if (cls == null) {
    938            return StringUtils.EMPTY;
    939        }
    940        return getShortClassName(cls.getName());
    941    }
    942
    943    /**
    944     * Gets the class name of the {@code object} without the package name or names.
    945     *
    946     * <p>
    947     * The method looks up the class of the object and then converts the name of the class invoking
    948     * {@link #getShortClassName(Class)} (see relevant notes there).
    949     * </p>
    950     *
    951     * @param object the class to get the short name for, may be {@code null}
    952     * @param valueIfNull the value to return if the object is {@code null}
    953     * @return the class name of the object without the package name, or {@code valueIfNull} if the argument {@code object}
    954     *         is {@code null}
    955     */
    956    public static String getShortClassName(final Object object, final String valueIfNull) {
    957        if (object == null) {
    958            return valueIfNull;
    959        }
    960        return getShortClassName(object.getClass());
    961    }
    962
    963    /**
    964     * Gets the class name minus the package name from a String.
    965     *
    966     * <p>
    967     * The string passed in is assumed to be a class name - it is not checked. The string has to be formatted the way as the
    968     * JDK method {@code Class.getName()} returns it, and not the usual way as we write it, for example in import
    969     * statements, or as it is formatted by {@code Class.getCanonicalName()}.
    970     * </p>
    971     *
    972     * <p>
    973     * The difference is is significant only in case of classes that are inner classes of some other classes. In this case
    974     * the separator between the outer and inner class (possibly on multiple hierarchy level) has to be {@code $} (dollar
    975     * sign) and not {@code .} (dot), as it is returned by {@code Class.getName()}
    976     * </p>
    977     *
    978     * <p>
    979     * Note that this method is called from the {@link #getShortClassName(Class)} method using the string returned by
    980     * {@code Class.getName()}.
    981     * </p>
    982     *
    983     * <p>
    984     * Note that this method differs from {@link #getSimpleName(Class)} in that this will return, for example
    985     * {@code "Map.Entry"} whilst the {@code java.lang.Class} variant will simply return {@code "Entry"}. In this example
    986     * the argument {@code className} is the string {@code java.util.Map$Entry} (note the {@code $} sign.
    987     * </p>
    988     *
    989     * @param className the className to get the short name for. It has to be formatted as returned by
    990     *        {@code Class.getName()} and not {@code Class.getCanonicalName()}
    991     * @return the class name of the class without the package name or an empty string. If the class is an inner class then
    992     *         value contains the outer class or classes and the separator is replaced to be {@code .} (dot) character.
    993     */
    994    public static String getShortClassName(String className) {
    995        if (StringUtils.isEmpty(className)) {
    996            return StringUtils.EMPTY;
    997        }
    998
    999        final StringBuilder arrayPrefix = new StringBuilder();
    1000
    1001        // Handle array encoding
    1002        if (className.startsWith("[")) {
    1003            while (className.charAt(0) == '[') {
    1004                className = className.substring(1);
    1005                arrayPrefix.append("[]");
    1006            }
    1007            // Strip Object type encoding
    1008            if (className.charAt(0) == 'L' && className.charAt(className.length() - 1) == ';') {
    1009                className = className.substring(1, className.length() - 1);
    1010            }
    1011
    1012            if (reverseAbbreviationMap.containsKey(className)) {
    1013                className = reverseAbbreviationMap.get(className);
    1014            }
    1015        }
    1016
    1017        final int lastDotIdx = className.lastIndexOf(PACKAGE_SEPARATOR_CHAR);
    1018        final int innerIdx = className.indexOf(INNER_CLASS_SEPARATOR_CHAR, lastDotIdx == -1 ? 0 : lastDotIdx + 1);
    1019        String out = className.substring(lastDotIdx + 1);
    1020        if (innerIdx != -1) {
    1021            out = out.replace(INNER_CLASS_SEPARATOR_CHAR, PACKAGE_SEPARATOR_CHAR);
    1022        }
    1023        return out + arrayPrefix;
    1024    }
    1025
    1026    /**
    1027     * Null-safe version of {@code cls.getSimpleName()}
    1028     *
    1029     * @param cls the class for which to get the simple name; may be null
    1030     * @return the simple class name or the empty string in case the argument is {@code null}
    1031     * @since 3.0
    1032     * @see Class#getSimpleName()
    1033     */
    1034    public static String getSimpleName(final Class<?> cls) {
    1035        return getSimpleName(cls, StringUtils.EMPTY);
    1036    }
    1037
    1038    /**
    1039     * Null-safe version of {@code cls.getSimpleName()}
    1040     *
    1041     * @param cls the class for which to get the simple name; may be null
    1042     * @param valueIfNull the value to return if null
    1043     * @return the simple class name or {@code valueIfNull} if the argument {@code cls} is {@code null}
    1044     * @since 3.0
    1045     * @see Class#getSimpleName()
    1046     */
    1047    public static String getSimpleName(final Class<?> cls, final String valueIfNull) {
    1048        return cls == null ? valueIfNull : cls.getSimpleName();
    1049    }
    1050
    1051    /**
    1052     * Null-safe version of {@code object.getClass().getSimpleName()}
    1053     *
    1054     * <p>
    1055     * It is to note that this method is overloaded and in case the argument {@code object} is a {@link Class} object then
    1056     * the {@link #getSimpleName(Class)} will be invoked. If this is a significant possibility then the caller should check
    1057     * this case and call {@code
    1058     * getSimpleName(Class.class)} or just simply use the string literal {@code "Class"}, which is the result of the method
    1059     * in that case.
    1060     * </p>
    1061     *
    1062     * @param object the object for which to get the simple class name; may be null
    1063     * @return the simple class name or the empty string in case the argument is {@code null}
    1064     * @since 3.7
    1065     * @see Class#getSimpleName()
    1066     */
    1067    public static String getSimpleName(final Object object) {
    1068        return getSimpleName(object, StringUtils.EMPTY);
    1069    }
    1070
    1071    /**
    1072     * Null-safe version of {@code object.getClass().getSimpleName()}
    1073     *
    1074     * @param object the object for which to get the simple class name; may be null
    1075     * @param valueIfNull the value to return if {@code object} is {@code null}
    1076     * @return the simple class name or {@code valueIfNull} if the argument {@code object} is {@code null}
    1077     * @since 3.0
    1078     * @see Class#getSimpleName()
    1079     */
    1080    public static String getSimpleName(final Object object, final String valueIfNull) {
    1081        return object == null ? valueIfNull : object.getClass().getSimpleName();
    1082    }
    1083
    1084    /**
    1085     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order,
    1086     * excluding interfaces.
    1087     *
    1088     * @param type the type to get the class hierarchy from
    1089     * @return Iterable an Iterable over the class hierarchy of the given class
    1090     * @since 3.2
    1091     */
    1092    public static Iterable<Class<?>> hierarchy(final Class<?> type) {
    1093        return hierarchy(type, Interfaces.EXCLUDE);
    1094    }
    1095
    1096    /**
    1097     * Gets an {@link Iterable} that can iterate over a class hierarchy in ascending (subclass to superclass) order.
    1098     *
    1099     * @param type the type to get the class hierarchy from
    1100     * @param interfacesBehavior switch indicating whether to include or exclude interfaces
    1101     * @return Iterable an Iterable over the class hierarchy of the given class
    1102     * @since 3.2
    1103     */
    1104    public static Iterable<Class<?>> hierarchy(final Class<?> type, final Interfaces interfacesBehavior) {
    1105        final Iterable<Class<?>> classes = () -> {
    1106            final MutableObject<Class<?>> next = new MutableObject<>(type);
    1107            return new Iterator<Class<?>>() {
    1108
    1109                @Override
    1110                public boolean hasNext() {
    1111                    return next.getValue() != null;
    1112                }
    1113
    1114                @Override
    1115                public Class<?> next() {
    1116                    final Class<?> result = next.getValue();
    1117                    next.setValue(result.getSuperclass());
    1118                    return result;
    1119                }
    1120
    1121                @Override
    1122                public void remove() {
    1123                    throw new UnsupportedOperationException();
    1124                }
    1125
    1126            };
    1127        };
    1128        if (interfacesBehavior != Interfaces.INCLUDE) {
    1129            return classes;
    1130        }
    1131        return () -> {
    1132            final Set<Class<?>> seenInterfaces = new HashSet<>();
    1133            final Iterator<Class<?>> wrapped = classes.iterator();
    1134
    1135            return new Iterator<Class<?>>() {
    1136                Iterator<Class<?>> interfaces = Collections.emptyIterator();
    1137
    1138                @Override
    1139                public boolean hasNext() {
    1140                    return interfaces.hasNext() || wrapped.hasNext();
    1141                }
    1142
    1143                @Override
    1144                public Class<?> next() {
    1145                    if (interfaces.hasNext()) {
    1146                        final Class<?> nextInterface = interfaces.next();
    1147                        seenInterfaces.add(nextInterface);
    1148                        return nextInterface;
    1149                    }
    1150                    final Class<?> nextSuperclass = wrapped.next();
    1151                    final Set<Class<?>> currentInterfaces = new LinkedHashSet<>();
    1152                    walkInterfaces(currentInterfaces, nextSuperclass);
    1153                    interfaces = currentInterfaces.iterator();
    1154                    return nextSuperclass;
    1155                }
    1156
    1157                @Override
    1158                public void remove() {
    1159                    throw new UnsupportedOperationException();
    1160                }
    1161
    1162                private void walkInterfaces(final Set<Class<?>> addTo, final Class<?> c) {
    1163                    for (final Class<?> iface : c.getInterfaces()) {
    1164                        if (!seenInterfaces.contains(iface)) {
    1165                            addTo.add(iface);
    1166                        }
    1167                        walkInterfaces(addTo, iface);
    1168                    }
    1169                }
    1170
    1171            };
    1172        };
    1173    }
    1174
    1175    /**
    1176     * Checks if one {@link Class} can be assigned to a variable of another {@link Class}.
    1177     *
    1178     * <p>
    1179     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1180     * primitive classes and {@code null}s.
    1181     * </p>
    1182     *
    1183     * <p>
    1184     * Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result
    1185     * for these cases.
    1186     * </p>
    1187     *
    1188     * <p>
    1189     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1190     * and the toClass is non-primitive.
    1191     * </p>
    1192     *
    1193     * <p>
    1194     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1195     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1196     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1197     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1198     * </p>
    1199     *
    1200     * <p>
    1201     * <strong>Since Lang 3.0,</strong> this method will default behavior for calculating assignability between primitive
    1202     * and wrapper types <em>corresponding to the running Java version</em>; i.e. autoboxing will be the default behavior in
    1203     * VMs running Java versions &gt; 1.5.
    1204     * </p>
    1205     *
    1206     * @param cls the Class to check, may be null
    1207     * @param toClass the Class to try to assign into, returns false if null
    1208     * @return {@code true} if assignment possible
    1209     */
    1210    public static boolean isAssignable(final Class<?> cls, final Class<?> toClass) {
    1211        return isAssignable(cls, toClass, true);
    1212    }
    1213
    1214    /**
    1215     * Checks if one {@link Class} can be assigned to a variable of another {@link Class}.
    1216     *
    1217     * <p>
    1218     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1219     * primitive classes and {@code null}s.
    1220     * </p>
    1221     *
    1222     * <p>
    1223     * Primitive widenings allow an int to be assigned to a long, float or double. This method returns the correct result
    1224     * for these cases.
    1225     * </p>
    1226     *
    1227     * <p>
    1228     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1229     * and the toClass is non-primitive.
    1230     * </p>
    1231     *
    1232     * <p>
    1233     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1234     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1235     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1236     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1237     * </p>
    1238     *
    1239     * @param cls the Class to check, may be null
    1240     * @param toClass the Class to try to assign into, returns false if null
    1241     * @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
    1242     * @return {@code true} if assignment possible
    1243     */
    1244    public static boolean isAssignable(Class<?> cls, final Class<?> toClass, final boolean autoboxing) {
    1245        if (toClass == null) {
    1246            return false;
    1247        }
    1248        // have to check for null, as isAssignableFrom doesn't
    1249        if (cls == null) {
    1250            return !toClass.isPrimitive();
    1251        }
    1252        // autoboxing:
    1253        if (autoboxing) {
    1254            if (cls.isPrimitive() && !toClass.isPrimitive()) {
    1255                cls = primitiveToWrapper(cls);
    1256                if (cls == null) {
    1257                    return false;
    1258                }
    1259            }
    1260            if (toClass.isPrimitive() && !cls.isPrimitive()) {
    1261                cls = wrapperToPrimitive(cls);
    1262                if (cls == null) {
    1263                    return false;
    1264                }
    1265            }
    1266        }
    1267        if (cls.equals(toClass)) {
    1268            return true;
    1269        }
    1270        if (cls.isPrimitive()) {
    1271            if (!toClass.isPrimitive()) {
    1272                return false;
    1273            }
    1274            if (Integer.TYPE.equals(cls)) {
    1275                return Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
    1276            }
    1277            if (Long.TYPE.equals(cls)) {
    1278                return Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
    1279            }
    1280            if (Boolean.TYPE.equals(cls)) {
    1281                return false;
    1282            }
    1283            if (Double.TYPE.equals(cls)) {
    1284                return false;
    1285            }
    1286            if (Float.TYPE.equals(cls)) {
    1287                return Double.TYPE.equals(toClass);
    1288            }
    1289            if (Character.TYPE.equals(cls)  || Short.TYPE.equals(cls)) {
    1290                return Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass) || Double.TYPE.equals(toClass);
    1291            }
    1292            if (Byte.TYPE.equals(cls)) {
    1293                return Short.TYPE.equals(toClass) || Integer.TYPE.equals(toClass) || Long.TYPE.equals(toClass) || Float.TYPE.equals(toClass)
    1294                    || Double.TYPE.equals(toClass);
    1295            }
    1296            // should never get here
    1297            return false;
    1298        }
    1299        return toClass.isAssignableFrom(cls);
    1300    }
    1301
    1302    /**
    1303     * Checks if an array of Classes can be assigned to another array of Classes.
    1304     *
    1305     * <p>
    1306     * This method calls {@link #isAssignable(Class, Class) isAssignable} for each Class pair in the input arrays. It can be
    1307     * used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter
    1308     * types (the second parameter).
    1309     * </p>
    1310     *
    1311     * <p>
    1312     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1313     * primitive classes and {@code null}s.
    1314     * </p>
    1315     *
    1316     * <p>
    1317     * Primitive widenings allow an int to be assigned to a {@code long}, {@code float} or {@code double}. This method
    1318     * returns the correct result for these cases.
    1319     * </p>
    1320     *
    1321     * <p>
    1322     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1323     * and the toClass is non-primitive.
    1324     * </p>
    1325     *
    1326     * <p>
    1327     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1328     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1329     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1330     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1331     * </p>
    1332     *
    1333     * <p>
    1334     * <strong>Since Lang 3.0,</strong> this method will default behavior for calculating assignability between primitive
    1335     * and wrapper types <em>corresponding to the running Java version</em>; i.e. autoboxing will be the default behavior in
    1336     * VMs running Java versions &gt; 1.5.
    1337     * </p>
    1338     *
    1339     * @param classArray the array of Classes to check, may be {@code null}
    1340     * @param toClassArray the array of Classes to try to assign into, may be {@code null}
    1341     * @return {@code true} if assignment possible
    1342     */
    1343    public static boolean isAssignable(final Class<?>[] classArray, final Class<?>... toClassArray) {
    1344        return isAssignable(classArray, toClassArray, true);
    1345    }
    1346
    1347    /**
    1348     * Checks if an array of Classes can be assigned to another array of Classes.
    1349     *
    1350     * <p>
    1351     * This method calls {@link #isAssignable(Class, Class) isAssignable} for each Class pair in the input arrays. It can be
    1352     * used to check if a set of arguments (the first parameter) are suitably compatible with a set of method parameter
    1353     * types (the second parameter).
    1354     * </p>
    1355     *
    1356     * <p>
    1357     * Unlike the {@link Class#isAssignableFrom(java.lang.Class)} method, this method takes into account widenings of
    1358     * primitive classes and {@code null}s.
    1359     * </p>
    1360     *
    1361     * <p>
    1362     * Primitive widenings allow an int to be assigned to a {@code long}, {@code float} or {@code double}. This method
    1363     * returns the correct result for these cases.
    1364     * </p>
    1365     *
    1366     * <p>
    1367     * {@code null} may be assigned to any reference type. This method will return {@code true} if {@code null} is passed in
    1368     * and the toClass is non-primitive.
    1369     * </p>
    1370     *
    1371     * <p>
    1372     * Specifically, this method tests whether the type represented by the specified {@link Class} parameter can be
    1373     * converted to the type represented by this {@link Class} object via an identity conversion widening primitive or
    1374     * widening reference conversion. See <em><a href="https://docs.oracle.com/javase/specs/">The Java Language
    1375     * Specification</a></em>, sections 5.1.1, 5.1.2 and 5.1.4 for details.
    1376     * </p>
    1377     *
    1378     * @param classArray the array of Classes to check, may be {@code null}
    1379     * @param toClassArray the array of Classes to try to assign into, may be {@code null}
    1380     * @param autoboxing whether to use implicit autoboxing/unboxing between primitives and wrappers
    1381     * @return {@code true} if assignment possible
    1382     */
    1383    public static boolean isAssignable(Class<?>[] classArray, Class<?>[] toClassArray, final boolean autoboxing) {
    1384        if (!ArrayUtils.isSameLength(classArray, toClassArray)) {
    1385            return false;
    1386        }
    1387        if (classArray == null) {
    1388            classArray = ArrayUtils.EMPTY_CLASS_ARRAY;
    1389        }
    1390        if (toClassArray == null) {
    1391            toClassArray = ArrayUtils.EMPTY_CLASS_ARRAY;
    1392        }
    1393        for (int i = 0; i < classArray.length; i++) {
    1394            if (!isAssignable(classArray[i], toClassArray[i], autoboxing)) {
    1395                return false;
    1396            }
    1397        }
    1398        return true;
    1399    }
    1400
    1401    /**
    1402     * Is the specified class an inner class or static nested class.
    1403     *
    1404     * @param cls the class to check, may be null
    1405     * @return {@code true} if the class is an inner or static nested class, false if not or {@code null}
    1406     */
    1407    public static boolean isInnerClass(final Class<?> cls) {
    1408        return cls != null && cls.getEnclosingClass() != null;
    1409    }
    1410
    1411    /**
    1412     * Tests whether a {@link Class} is public.
    1413     * @param cls Class to test.
    1414     * @return {@code true} if {@code cls} is public.
    1415     * @since 3.13.0
    1416     */
    1417    public static boolean isPublic(final Class<?> cls) {
    1418        return Modifier.isPublic(cls.getModifiers());
    1419    }
    1420    /**
    1421     * Returns whether the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte},
    1422     * {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1423     *
    1424     * @param type The class to query or null.
    1425     * @return true if the given {@code type} is a primitive or primitive wrapper ({@link Boolean}, {@link Byte},
    1426     *         {@link Character}, {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1427     * @since 3.1
    1428     */
    1429    public static boolean isPrimitiveOrWrapper(final Class<?> type) {
    1430        if (type == null) {
    1431            return false;
    1432        }
    1433        return type.isPrimitive() || isPrimitiveWrapper(type);
    1434    }
    1435
    1436    /**
    1437     * Returns whether the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
    1438     * {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1439     *
    1440     * @param type The class to query or null.
    1441     * @return true if the given {@code type} is a primitive wrapper ({@link Boolean}, {@link Byte}, {@link Character},
    1442     *         {@link Short}, {@link Integer}, {@link Long}, {@link Double}, {@link Float}).
    1443     * @since 3.1
    1444     */
    1445    public static boolean isPrimitiveWrapper(final Class<?> type) {
    1446        return wrapperPrimitiveMap.containsKey(type);
    1447    }
    1448
    1449    /**
    1450     * Converts the specified array of primitive Class objects to an array of its corresponding wrapper Class objects.
    1451     *
    1452     * @param classes the class array to convert, may be null or empty
    1453     * @return an array which contains for each given class, the wrapper class or the original class if class is not a
    1454     *         primitive. {@code null} if null input. Empty array if an empty array passed in.
    1455     * @since 2.1
    1456     */
    1457    public static Class<?>[] primitivesToWrappers(final Class<?>... classes) {
    1458        if (classes == null) {
    1459            return null;
    1460        }
    1461
    1462        if (classes.length == 0) {
    1463            return classes;
    1464        }
    1465
    1466        final Class<?>[] convertedClasses = new Class[classes.length];
    1467        Arrays.setAll(convertedClasses, i -> primitiveToWrapper(classes[i]));
    1468        return convertedClasses;
    1469    }
    1470
    1471    /**
    1472     * Converts the specified primitive Class object to its corresponding wrapper Class object.
    1473     *
    1474     * <p>
    1475     * NOTE: From v2.2, this method handles {@code Void.TYPE}, returning {@code Void.TYPE}.
    1476     * </p>
    1477     *
    1478     * @param cls the class to convert, may be null
    1479     * @return the wrapper class for {@code cls} or {@code cls} if {@code cls} is not a primitive. {@code null} if null
    1480     *         input.
    1481     * @since 2.1
    1482     */
    1483    public static Class<?> primitiveToWrapper(final Class<?> cls) {
    1484        Class<?> convertedClass = cls;
    1485        if (cls != null && cls.isPrimitive()) {
    1486            convertedClass = primitiveWrapperMap.get(cls);
    1487        }
    1488        return convertedClass;
    1489    }
    1490
    1491    /**
    1492     * Converts a class name to a JLS style class name.
    1493     *
    1494     * @param className the class name
    1495     * @return the converted name
    1496     * @throws NullPointerException if the className is null
    1497     */
    1498    private static String toCanonicalName(final String className) {
    1499        String canonicalName = StringUtils.deleteWhitespace(className);
    1500        Objects.requireNonNull(canonicalName, "className");
    1501        if (canonicalName.endsWith("[]")) {
    1502            final StringBuilder classNameBuffer = new StringBuilder();
    1503            while (canonicalName.endsWith("[]")) {
    1504                canonicalName = canonicalName.substring(0, canonicalName.length() - 2);
    1505                classNameBuffer.append("[");
    1506            }
    1507            final String abbreviation = abbreviationMap.get(canonicalName);
    1508            if (abbreviation != null) {
    1509                classNameBuffer.append(abbreviation);
    1510            } else {
    1511                classNameBuffer.append("L").append(canonicalName).append(";");
    1512            }
    1513            canonicalName = classNameBuffer.toString();
    1514        }
    1515        return canonicalName;
    1516    }
    1517
    1518    /**
    1519     * Converts an array of {@link Object} in to an array of {@link Class} objects. If any of these objects is null, a null
    1520     * element will be inserted into the array.
    1521     *
    1522     * <p>
    1523     * This method returns {@code null} for a {@code null} input array.
    1524     * </p>
    1525     *
    1526     * @param array an {@link Object} array
    1527     * @return a {@link Class} array, {@code null} if null array input
    1528     * @since 2.4
    1529     */
    1530    public static Class<?>[] toClass(final Object... array) {
    1531        if (array == null) {
    1532            return null;
    1533        }
    1534        if (array.length == 0) {
    1535            return ArrayUtils.EMPTY_CLASS_ARRAY;
    1536        }
    1537        final Class<?>[] classes = new Class[array.length];
    1538        Arrays.setAll(classes, i -> array[i] == null ? null : array[i].getClass());
    1539        return classes;
    1540    }
    1541
    1542    /**
    1543     * Decides if the part that was just copied to its destination location in the work array can be kept as it was copied
    1544     * or must be abbreviated. It must be kept when the part is the last one, which is the simple name of the class. In this
    1545     * case the {@code source} index, from where the characters are copied points one position after the last character,
    1546     * a.k.a. {@code source ==
    1547     * originalLength}
    1548     *
    1549     * <p>
    1550     * If the part is not the last one then it can be kept unabridged if the number of the characters copied so far plus the
    1551     * character that are to be copied is less than or equal to the desired length.
    1552     * </p>
    1553     *
    1554     * @param runAheadTarget the target index (where the characters were copied to) pointing after the last character copied
    1555     *        when the current part was copied
    1556     * @param source the source index (where the characters were copied from) pointing after the last character copied when
    1557     *        the current part was copied
    1558     * @param originalLength the original length of the class full name, which is abbreviated
    1559     * @param desiredLength the desired length of the abbreviated class name
    1560     * @return {@code true} if it can be kept in its original length {@code false} if the current part has to be abbreviated
    1561     *         and
    1562     */
    1563    private static boolean useFull(final int runAheadTarget, final int source, final int originalLength, final int desiredLength) {
    1564        return source >= originalLength || runAheadTarget + originalLength - source <= desiredLength;
    1565    }
    1566
    1567    /**
    1568     * Converts the specified array of wrapper Class objects to an array of its corresponding primitive Class objects.
    1569     *
    1570     * <p>
    1571     * This method invokes {@code wrapperToPrimitive()} for each element of the passed in array.
    1572     * </p>
    1573     *
    1574     * @param classes the class array to convert, may be null or empty
    1575     * @return an array which contains for each given class, the primitive class or <b>null</b> if the original class is not
    1576     *         a wrapper class. {@code null} if null input. Empty array if an empty array passed in.
    1577     * @see #wrapperToPrimitive(Class)
    1578     * @since 2.4
    1579     */
    1580    public static Class<?>[] wrappersToPrimitives(final Class<?>... classes) {
    1581        if (classes == null) {
    1582            return null;
    1583        }
    1584
    1585        if (classes.length == 0) {
    1586            return classes;
    1587        }
    1588
    1589        final Class<?>[] convertedClasses = new Class[classes.length];
    1590        Arrays.setAll(convertedClasses, i -> wrapperToPrimitive(classes[i]));
    1591        return convertedClasses;
    1592    }
    1593
    1594    /**
    1595     * Converts the specified wrapper class to its corresponding primitive class.
    1596     *
    1597     * <p>
    1598     * This method is the counter part of {@code primitiveToWrapper()}. If the passed in class is a wrapper class for a
    1599     * primitive type, this primitive type will be returned (e.g. {@code Integer.TYPE} for {@code Integer.class}). For other
    1600     * classes, or if the parameter is <b>null</b>, the return value is <b>null</b>.
    1601     * </p>
    1602     *
    1603     * @param cls the class to convert, may be <b>null</b>
    1604     * @return the corresponding primitive type if {@code cls} is a wrapper class, <b>null</b> otherwise
    1605     * @see #primitiveToWrapper(Class)
    1606     * @since 2.4
    1607     */
    1608    public static Class<?> wrapperToPrimitive(final Class<?> cls) {
    1609        return wrapperPrimitiveMap.get(cls);
    1610    }
    1611
    1612    /**
    1613     * ClassUtils instances should NOT be constructed in standard programming. Instead, the class should be used as
    1614     * {@code ClassUtils.getShortClassName(cls)}.
    1615     *
    1616     * <p>
    1617     * This constructor is public to permit tools that require a JavaBean instance to operate.
    1618     * </p>
    1619     */
    1620    public ClassUtils() {
    1621    }
    1622
    1623}