Add encoding parameter to read and write properties files

src/main/java/org/codehaus/mojo/properties/AbstractWritePropertiesMojo.java

@@ -32,6 +32,7 @@
 import java.io.PrintWriter;
 import java.io.StringReader;
 import java.io.StringWriter;
+import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -44,13 +45,52 @@
 public abstract class AbstractWritePropertiesMojo
     extends AbstractMojo
 {
+    /**
+     * Default encoding for the output file. Package private for testing.
+     */
+    static final String DEFAULT_ENCODING = "ISO-8859-1";
 
     @Parameter( defaultValue = "${project}", required = true, readonly = true )
     private MavenProject project;
 
     @Parameter( required = true, property = "properties.outputFile" )
     private File outputFile;
 
+    /**
+     * The encoding to use when writing the properties file.
+     */
+    @Parameter( required = false, defaultValue = DEFAULT_ENCODING )
+    private String encoding = DEFAULT_ENCODING;
+
+    /**
+     * Default scope for test access.
+     *
+     * @param project The test project.
+     */
+    void setProject( MavenProject project )
+    {
+        this.project = project;
+    }
+
+    /**
+     * Default scope for test access.
+     *
+     * @param encoding to write the output file in
+     */
+    void setEncoding( String encoding )
+    {
+        this.encoding = encoding;
+    }
+
+    /**
+     * Default scope for test access
+     *
+     * @param outputFile the outputFile to set
+     */
+    void setOutputFile(File outputFile) {
+        this.outputFile = outputFile;
+    }
+
     /**
      * @param properties {@link Properties}
      * @param file {@link File}
@@ -59,6 +99,8 @@ public abstract class AbstractWritePropertiesMojo
     protected void writeProperties( Properties properties, File file )
         throws MojoExecutionException
     {
+        getLog().debug( String.format( "Writing properties to %s using encoding %s", file.toString(),  this.encoding ) );
+
         try
         {
             storeWithoutTimestamp( properties, file, "Properties" );
@@ -79,7 +121,7 @@ protected void writeProperties( Properties properties, File file )
     private void storeWithoutTimestamp( Properties properties, File outputFile, String comments )
         throws IOException
     {
-        try ( PrintWriter pw = new PrintWriter( outputFile, "ISO-8859-1" ); StringWriter sw = new StringWriter() )
+        try ( PrintWriter pw = new PrintWriter( outputFile, this.encoding ); StringWriter sw = new StringWriter() )
         {
             properties.store( sw, comments );
             comments = '#' + comments;
@@ -122,6 +164,21 @@ protected void validateOutputFile()
         }
     }
 
+    /**
+     * @throws MojoExecutionException {@link MojoExecutionException}
+     */
+    protected void validateEncoding()
+        throws MojoExecutionException
+    {
+        try
+        {
+            Charset.forName(this.encoding);
+        }
+        catch(IllegalArgumentException e)
+        {
+            throw new MojoExecutionException(String.format("Invalid encoding '%s'", this.encoding), e);
+        }
+    }
     /**
      * @return {@link MavenProject}
      */

src/main/java/org/codehaus/mojo/properties/ReadPropertiesMojo.java

@@ -24,8 +24,10 @@
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.nio.charset.Charset;
 import java.util.Enumeration;
 import java.util.Properties;
 
@@ -50,6 +52,11 @@
 public class ReadPropertiesMojo
     extends AbstractMojo
 {
+    /**
+     * Default encoding for the input properties file/url. Package private for testing.
+     */
+    static final String DEFAULT_ENCODING = "ISO-8859-1";
+
     @Parameter( defaultValue = "${project}", readonly = true, required = true )
     private MavenProject project;
 
@@ -122,6 +129,16 @@ public void setKeyPrefix( String keyPrefix )
     @Parameter( defaultValue = "false", property = "prop.skipLoadProperties" )
     private boolean skipLoadProperties;
 
+    /**
+     * The encoding of the properties files.
+     */
+    @Parameter( required = false, defaultValue = DEFAULT_ENCODING )
+    private String encoding = DEFAULT_ENCODING;
+
+    void setEncoding ( String encoding ) {
+        this.encoding = encoding;
+    }
+
     /**
      * Used for resolving property placeholders.
      */
@@ -152,6 +169,14 @@ private void checkParameters()
             throw new MojoExecutionException( "Set files or URLs but not both - otherwise "
                 + "no order of precedence can be guaranteed" );
         }
+        try
+        {
+            Charset.forName(this.encoding);
+        }
+        catch(IllegalArgumentException e)
+        {
+            throw new MojoExecutionException(String.format("Invalid encoding '%s'", this.encoding), e);
+        }
     }
 
     private void loadFiles()
@@ -190,23 +215,26 @@ private void loadProperties( Resource resource )
     {
         try
         {
-            getLog().debug( "Loading properties from " + resource );
+            getLog().debug( String.format( "Loading properties from %s using encoding %s", resource.toString(),  this.encoding ) );
 
             try ( InputStream stream = resource.getInputStream() )
             {
-                if ( keyPrefix != null )
+                try (InputStreamReader streamReader = new InputStreamReader( stream, this.encoding ) )
                 {
-                    Properties properties = new Properties();
-                    properties.load( stream );
-                    Properties projectProperties = project.getProperties();
-                    for ( String key : properties.stringPropertyNames() )
+                    if ( keyPrefix != null )
                     {
-                        projectProperties.put( keyPrefix + key, properties.get( key ) );
+                        Properties properties = new Properties();
+                        properties.load( streamReader );
+                        Properties projectProperties = project.getProperties();
+                        for ( String key : properties.stringPropertyNames() )
+                        {
+                            projectProperties.put( keyPrefix + key, properties.get( key ) );
+                        }
+                    }
+                    else
+                    {
+                        project.getProperties().load( streamReader );
                     }
-                }
-                else
-                {
-                    project.getProperties().load( stream );
                 }
             }
         }

src/main/java/org/codehaus/mojo/properties/WriteActiveProfileProperties.java

@@ -41,6 +41,7 @@ public void execute()
         throws MojoExecutionException
     {
         validateOutputFile();
+        validateEncoding();
         List<Profile> list = getProject().getActiveProfiles();
         if ( getLog().isInfoEnabled() )
         {

src/main/java/org/codehaus/mojo/properties/WriteProjectProperties.java

@@ -60,6 +60,7 @@ public void execute()
         throws MojoExecutionException
     {
         validateOutputFile();
+        validateEncoding();
         Properties projProperties = new Properties();
         projProperties.putAll( getProject().getProperties() );