Groovy example source code file (MessageSource.java)

This example Groovy source code file (MessageSource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

class, class, groovyobjectsupport, messagesource, messagesource, missingresourceexception, object, resourcebundle, resourcebundle, string, string, text, util

The Groovy MessageSource.java source code

/*
 * Copyright 2003-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.codehaus.groovy.tools.shell.util;

import java.util.ResourceBundle;
import java.util.MissingResourceException;

import java.text.MessageFormat;

import groovy.lang.GroovyObjectSupport;

/**
 * Message source backed up by one or more {@link java.util.ResourceBundle}
 * instances for simple i18n support.
 *
 * @version $Id: MessageSource.java 19543 2010-03-11 07:58:19Z paulk $
 * @author <a href="mailto:jason@planet57.com">Jason Dillon
 */
public class MessageSource
    extends GroovyObjectSupport
{
    private final String[] bundleNames;
    
    private ResourceBundle[] cachedBundles;
    
    public MessageSource(final String[] names) {
        assert names != null;
        assert names.length != 0;
        
        this.bundleNames = names;
    }
    
    public MessageSource(final String name) {
        this(new String[] { name });
    }
    
    private static String[] classNames(final Class[] types) {
        assert types != null;
        assert types.length != 0;
        
        String[] names = new String[types.length];
        
        for (int i=0; i<types.length; i++) {
            assert types[i] != null;
            
            names[i] = types[i].getName();
        }
        
        return names;
    }
    
    public MessageSource(final Class[] types) {
        this(classNames(types));
    }
    
    public MessageSource(final Class type) {
        this(new String[] { type.getName() });
    }
    
    private ResourceBundle[] createBundles() {
        ResourceBundle[] bundles = new ResourceBundle[bundleNames.length];
        
        for (int i=0; i<bundleNames.length; i++) {
            assert bundleNames[i] != null;
            
            bundles[i] = ResourceBundle.getBundle(bundleNames[i]);
        }
        
        return bundles;
    }
    
    private ResourceBundle[] getBundles() {
        if (cachedBundles == null) {
            cachedBundles = createBundles();
        }
        return cachedBundles;
    }
    
    /**
     * Get a raw message from the resource bundles using the given code.
     */
    public String getMessage(final String code) {
        assert code != null;
        
        MissingResourceException error = null;
        
        ResourceBundle[] bundles = getBundles();
        
        for (int i=0; i<bundles.length; i++) {
            try {
                return bundles[i].getString(code);
            }
            catch (MissingResourceException e) {
                //
                // FIXME: For now just save the first error, should really roll a new message with all of the details
                //
                
                if (error != null) {
                    error = e;
                }
            }
        }
        
        assert error != null;
        
        throw error;
    }
    
    /**
     * Format a message (based on {@link MessageFormat} using the message
     * from the resource bundles using the given code as a pattern and the
     * given objects as arguments.
     */
    public String format(final String code, final Object[] args) {
        assert args != null;
        
        String pattern = getMessage(code);
        
        return MessageFormat.format(pattern, args);
    }
    
    /**
     * @see #getMessage(String)
     */
    public Object getProperty(final String name) {
        return getMessage(name);
    }
}