Wrong encoding after activating resource filtering

Question

I am developing a maven based web project. In my web module I am using different language specific resource bundles (german, spain, ....). All my sources are based on UTF-8 and erverything works fine. Now it was necessary to acitvate maven resouce filtering to replace some configurations depending on different maven profiles.

my pom.xml:

.....
 <project xmlns="http://maven.apache.org/POM/4.0.0"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
.....

 <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 </properties>    
 <build>
 <resources>
    <resource>
    <directory>src/main/resources</directory>
        <filtering>true</filtering>             
    </resource>      
 </resources>
 ....

From this moment my war file contains resource bundles with wrong encoding. For example German umlauts are no longer displayed in my web application correctly. When I disable the resource filtering everything is well again.

The only solution I found was to set the property project.build.sourceEncoding to 'ISO-8859-1'

<properties>
  <project.build.sourceEncoding>ISO-8859-1</project.build.sourceEncoding>
</properties>

But I can not understand why this is necessary? All my sources are UTF-8 and also my application is based on UTF-8? What will happen if I need to add a resource bundle with - for example Japanese characters?

I am developing on linux using Eclipse 4.2 and Maven 3

Answer 1

You can specify the encoding in the resources plugin configuration like so:

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-resources-plugin</artifactId>
        <version>2.6</version>
        <configuration>
          ...
          <encoding>UTF-8</encoding>
          ...
        </configuration>
      </plugin>
    </plugins>
    ...
  </build>
  ...
</project>

Link to the Docs

Answer 2

Are you sure your resource bundles (.properties) are using UTF-8?

java.util.Properties assumes ISO-8859-1 for resource bundles encoding, see http://docs.oracle.com/javase/6/docs/api/java/util/Properties.html#load(java.io.Reader), and I think Eclipse (as well as IntelliJ IDEA) honors this default encoding for these files (.properties).

So go and check with a text editor the current encoding for these files in your project source tree, in Windows Notepad 2 can help you with this.

And then configure maven-resources-plugin like indicated here Configure encoding for different filetypes in maven?