/*
* Copyright 2014 The original 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.vaadin.spring.stuff.i18n;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.text.MessageFormat;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.PropertyResourceBundle;
import java.util.ResourceBundle;
/**
* Implementation of {@link org.vaadin.spring.stuff.i18n.MessageProvider} that reads messages
* from {@link java.util.ResourceBundle}s with a specific base name.
*
* @author Petter Holmström (petter@vaadin.com)
*/
public class ResourceBundleMessageProvider implements MessageProvider {
private static final Logger LOGGER = LoggerFactory.getLogger(ResourceBundleMessageProvider.class);
private final String baseName;
private final String encoding;
/**
* Creates a new {@code ResourceBundleMessageProvider} with the given base name and UTF-8 encoding.
*
* @param baseName the base name to use, must not be {@code null}.
*/
public ResourceBundleMessageProvider(String baseName) {
this(baseName, "UTF-8");
}
/**
* Creates a new {@code ResourceBundleMessageProvider} with the given base name and encoding.
*
* @param baseName the base name to use, must not be {@code null}.
* @param encoding the encoding to use when reading the resource bundle, must not be {@code null}.
*/
public ResourceBundleMessageProvider(String baseName, String encoding) {
this.baseName = baseName;
this.encoding = encoding;
}
@Override
public MessageFormat resolveCode(String s, Locale locale) {
final ResourceBundle resourceBundle = getResourceBundle(locale);
final String message = getString(resourceBundle, s);
return getMessageFormat(message, locale);
}
private ResourceBundle getResourceBundle(Locale locale) {
try {
return ResourceBundle.getBundle(baseName, locale, new MessageControl());
} catch (MissingResourceException ex) {
LOGGER.warn("No message bundle with basename [{}] found for locale [{}]", baseName, locale);
return null;
}
}
private String getString(ResourceBundle bundle, String s) {
if (bundle == null) {
return null;
}
try {
return bundle.getString(s);
} catch (MissingResourceException ex) {
return null;
}
}
private MessageFormat getMessageFormat(String message, Locale locale) {
if (message == null) {
return null;
}
return new MessageFormat(message, locale);
}
private class MessageControl extends ResourceBundle.Control {
@Override
public ResourceBundle newBundle(String baseName, Locale locale, String format, ClassLoader loader, boolean reload) throws IllegalAccessException, InstantiationException, IOException {
if ("java.properties".equals(format)) {
final String resourceName = toResourceName(toBundleName(baseName, locale), "properties");
final InputStream stream = loader.getResourceAsStream(resourceName);
if (stream == null) {
return null; // Not found
}
Reader reader = null;
try {
reader = new InputStreamReader(stream, encoding);
return new PropertyResourceBundle(reader);
} catch (UnsupportedEncodingException ex) {
stream.close();
throw ex;
} finally {
if (reader != null) {
reader.close();
}
}
} else {
return super.newBundle(baseName, locale, format, loader, reload);
}
}
}
}