Normally, I write my internationalisation (i18n) files in UTF-8 format. This means that they are human readable.

Java i18n files however must be ISO-8859-1. If you don't process them using something like native2ascii, accented and multibyte characters will return gobbledegook at best.

You can manually convert a single file manually using this command:

native2ascii -encoding utf-8 ./src/main/resources/i18n.properties ./target/classes/i18n.properties

That's tedious, so why not automate the process during the build?

Using native2ascii-maven-plugin

Luckily, there's a maven plugin called native2ascii-maven-plugin. Its old, but does the job.

For Atlassian SDK p2 add-ons, use something like this:

<build>

    <plugins>

        <plugin>

            <groupId>org.codehaus.mojo</groupId>

            <artifactId>native2ascii-maven-plugin</artifactId>

            <version>1.0-alpha-1</version>

            <executions>

                <execution>

                    <id>native2ascii-utf8-properties</id>

                    <goals>

                        <goal>native2ascii</goal>

                    </goals>

                    <configuration>

                        <src>src/main/resources</src>

                        <includes>*.properties</includes>

                        <encoding>UTF8</encoding>

                        <dest>target/classes</dest>

                    </configuration>

                </execution>

            </executions>

            <!-- For Java 7+ compilation: -->

            <dependencies>

                <dependency>

                    <groupId>com.sun</groupId>

                    <artifactId>tools</artifactId>

                    <version>1.5.0</version>

                    <scope>system</scope>

                    <systemPath>${java.home}/../lib/tools.jar</systemPath>

                </dependency>

            </dependencies>

        </plugin>

		...

    </plugins>

</build>

Your source files will be in sweet UTF-8 format and your target files will be mangled into ISO-8859-1 as Java requires.

How do you do this? Please add a comment below with details.

Update: Maven resource filtering can mess with the working of this plugin, so try with no resource filtering first ;)