= Native mode
:page-aliases: native-mode.adoc

Things to consider before you run your application in native mode.

[[charsets]]
== Character encodings

By default, not all `Charsets` are available in native mode.

As such, you may face situations where an encoding is missing in native mode, for instance an application throwing `UnsupportedCharsetException`.
In such a case, you may consider using the configuration option below:

[source,properties]
----
quarkus.native.add-all-charsets = true
----

See also https://quarkus.io/guides/all-config#quarkus-core_quarkus.native.add-all-charsets[quarkus.native.add-all-charsets] in Quarkus documentation.

[[locale]]
== Locale

By default, only the building JVM default locale is included in the native image.
Quarkus provides a way to set the locale via `application.properties`, so that you do not need to rely on `LANG` and `LC_*` environment variables:

[source,properties]
----
quarkus.native.user-country=US
quarkus.native.user-language=en
----

There is also support for embedding multiple locales into the native image
and for selecting the default locale via GraalVM command line options `-H:IncludeLocales=fr,en`, `H:+IncludeAllLocales` and `-H:DefaultLocale=de`.
You can set those via the Quarkus `quarkus.native.additional-build-args` property.

[[embedding-resource-in-native-executable]]
== Embedding resources in the native executable

Resources accessed via `Class.getResource()`, `Class.getResourceAsStream()`, `ClassLoader.getResource()`,
`ClassLoader.getResourceAsStream()`, etc. at runtime need to be explicitly listed for including in the native executable.

This can be done using Quarkus `quarkus.native.resources.includes` and `quarkus.native.resources.excludes` properties
in `application.properties` file as demonstrated below:

[source,properties]
----
quarkus.native.resources.includes = docs/*,images/*
quarkus.native.resources.excludes = docs/ignored.adoc,images/ignored.png
----

In the example above, resources named `docs/included.adoc` and `images/included.png` would be embedded in the native executable
while `docs/ignored.adoc` and `images/ignored.png` would not.

`resources.includes` and `resources.excludes` are both lists of comma separated Ant-path style glob patterns.
Please refer to https://quarkus.io/guides/building-native-image#quarkus-native-pkg-native-config_quarkus.native.resources.includes[Quarkus documentation] for more details.

[[using-onexception-clause-in-native-mode]]
== Using the onException clause in native mode

When using xref:manual::exception-clause.adoc[Camel `onException` handling] in native mode, it is the application developers responsibility to register the exception classes for reflection.

For instance, with an exception handler like this

[source,java]
----
onException(MyException.class).handled(true);
from("direct:route-that-could-produce-my-exception").throw(MyException.class);
----

the class `MyException` should be registered for reflection, see more in xref:user-guide/native-mode.adoc#reflection[Registering classes for reflection].

[[reflection]]
== Registering classes for reflection

By default, dynamic reflection is not available in native mode. Classes for which reflective access is needed, have to be
registered for reflection at compile time.

In many cases, application developers do not need to care because Quarkus extensions are able to detect the classes that
require reflection and register them automatically.

However, in some situations, Quarkus extensions may miss some classes and it is up to the application developer to
register them. There are two ways to do that:

1. The `https://quarkus.io/guides/writing-native-applications-tips#alternative-with-registerforreflection[@io.quarkus.runtime.annotations.RegisterForReflection]`
annotation can be used to register classes on which it is used, or it can also register third party classes via
its `targets` attribute.
+
[source,java]
----
import io.quarkus.runtime.annotations.RegisterForReflection;

@RegisterForReflection
class MyClassAccessedReflectively {
}

@RegisterForReflection(
    targets = {
        org.third-party.Class1.class,
        org.third-party.Class2.class
    }
)
class ReflectionRegistrations {
}

----


2. The `quarkus.camel.native.reflection` options in `application.properties`:
+
[source,properties]
----
quarkus.camel.native.reflection.include-patterns = org.apache.commons.lang3.tuple.*
quarkus.camel.native.reflection.exclude-patterns = org.apache.commons.lang3.tuple.*Triple
----
+
For these options to work properly, the artifacts containing the selected classes
must either contain a Jandex index (`META-INF/jandex.idx`) or they must
be registered for indexing using the `quarkus.index-dependency.*` options
in `application.properties` - e.g.
+
[source,properties]
----
quarkus.index-dependency.commons-lang3.group-id = org.apache.commons
quarkus.index-dependency.commons-lang3.artifact-id = commons-lang3
----

[[serialization]]
== Registering classes for serialization

If serialization support is requested via `quarkus.camel.native.reflection.serialization-enabled`, the classes listed in https://github.com/apache/camel-quarkus/blob/main/extensions-core/core/deployment/src/main/java/org/apache/camel/quarkus/core/deployment/CamelSerializationProcessor.java[CamelSerializationProcessor.BASE_SERIALIZATION_CLASSES] are automatically registered for serialization.

Users can register more classes using `@io.quarkus.runtime.annotations.RegisterForReflection(serialization = true)`.
