What is this?

This small tool reads your property files and generate Java classes that enables type-safe access to message resources.

For example, when you have a property file called org/acme/Messages.properties that looks like this:

foo=error at {0} with {1}

This tool generates the following org/acme/Messages.java:

public class Messages {  
     
   private final static ResourceBundleHolder holder = new ResourceBundleHolder(Messages.class);
   
  /**  
    * error at {0} with {1}  
    */  
  public static String foo(Object arg1, Object arg2) {  
      return holder.format("foo",arg1,arg2);  
  }  
     
   /**  
     * error at {0} with {1}  
     */  
  public static Localizable _foo(Object arg1, Object arg2) {  
      return new Localizable(holder, "foo", arg1, arg2);  
  }  
}

The first method formats the message by using the default locale, and the second method returns an object that can be later formatted into String by specifying Locale.

In this way, you can get auto-completion on choosing the right message, you'll never refer to a non-existent message, and you'll always use the right number of arguments.

How to use this?

Maven

For projects built with Maven, add the following entries to your POM.

For the list of configurations to the localizer-maven-plugin, refer to this document:

<build>
    ...
    <plugins>
        ...
        <plugin>
            <groupId>org.jvnet.localizer</groupId>
            <artifactId>localizer-maven-plugin</artifactId>
            <version>1.28</version>
            <executions>
                <execution>
                    <goals>
                        <goal>generate</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>
<dependencies>
    <dependency>
        <groupId>org.jvnet.localizer</groupId>
        <artifactId>localizer</artifactId>
        <version>1.28</version>
    </dependency>
    ...
</dependencies>
<repositories>
    <repository>
        <id>jenkins-repo</id>
        <url>https://repo.jenkins-ci.org/releases/</url>
    </repository>
    ...
</repositories>
<pluginRepositories>
    <pluginRepository>
        <id>jenkins-repo</id>
        <url>https://repo.jenkins-ci.org/releases/</url>
    </pluginRepository>
</pluginRepositories>

Ant

For projects built with Ant, use the following task to generate source files:

<taskdef name="localizer-gen" classname="org.jvnet.localizer.GeneratorTask">
    <classpath>
        <pathelement location="path/to/localizer-maven-plugin.jar"/>
        <pathelement location="path/to/localizer.jar"/>
    </classpath>
</taskdef>
<localizer-gen todir="build/geenrated-sources" dir="./resources">
    <include name="**/Messages.properties"/>
</localizer-gen>

The localizer-gen task is a matching task, so you can use the usual FileSet-based filtering technique to specify the property files to be processed.

Using LocaleProvider

When you use methods that return String, the implementation consults a singleton LocaleProvider for determining the locale to be used.

The default implementation simply returns Locale.getDefault(), but in other situations (for example in web apps), you can have this method return different locales (for example by using ServletRequest.getLocale().)