// Copyright 2004 The Apache Software Foundation
//
// 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.apache.hivemind.impl;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.hivemind.HiveMind;
import org.apache.hivemind.Messages;
import org.apache.hivemind.Resource;
import org.apache.hivemind.util.LocalizedNameGenerator;
/**
* Implementation of {@link org.apache.hivemind.Messages} for
* a {@link org.apache.hivemind.internal.Module}.
*
* TODO: Refactor this and {@link org.apache.hivemind.impl.MessageFormatter} into
* common base classes.
*
* @author Howard Lewis Ship
*/
public final class MessagesImpl implements Messages
{
private static final Log LOG = LogFactory.getLog(MessagesImpl.class);
private Properties _properties;
private Locale _locale;
public MessagesImpl(Resource moduleLocation, Locale locale)
{
_locale = locale;
initialize(moduleLocation);
}
private void initialize(Resource moduleLocation)
{
if (LOG.isDebugEnabled())
LOG.debug("Reading message properties for module at " + moduleLocation);
String descriptorName = moduleLocation.getName();
int dotx = descriptorName.lastIndexOf('.');
String baseName = descriptorName.substring(0, dotx);
LocalizedNameGenerator g = new LocalizedNameGenerator(baseName, _locale, ".properties");
List urls = new ArrayList();
while (g.more())
{
String name = g.next();
Resource l = moduleLocation.getRelativeResource(name);
URL url = l.getResourceURL();
if (url != null)
urls.add(url);
}
// Now read an assemble them, least specific to most specific.
// More specific keys overwrite less specific keys.
int count = urls.size();
_properties = new Properties();
for (int i = count - 1; i >= 0; i--)
{
URL url = (URL) urls.get(i);
if (LOG.isDebugEnabled())
LOG.debug("Reading message properties from " + url);
try
{
InputStream stream = url.openStream();
_properties.load(stream);
stream.close();
}
catch (IOException ex)
{
throw new ApplicationRuntimeException(ImplMessages.unabelToReadMessages(url), ex);
}
}
}
public String getMessage(String key)
{
String result = _properties.getProperty(key);
if (result == null)
result = "[" + key.toUpperCase() + "]";
// Reasons not to write the result back in as a new property:
// 1) This is a developer error that should be resolved before an app goes into production
// 2) Would have to synchronize getMessage() methods
// 3) Would screw up #getMessage(String, String)
return result;
}
public String getMessage(String key, String defaultValue)
{
return _properties.getProperty(key, defaultValue);
}
public String format(String key, Object[] args)
{
String pattern = getMessage(key);
for (int i = 0; i < args.length; i++)
{
Object arg = args[i];
if (arg != null && arg instanceof Throwable)
args[i] = extractMessage((Throwable) arg);
}
// This ugliness is mandated for JDK 1.3 compatibility, which has a bug
// in MessageFormat ... the
// pattern is applied in the constructor, using the system default Locale,
// regardless of what locale is later specified!
// It appears that the problem does not exist in JDK 1.4.
MessageFormat messageFormat = new MessageFormat("");
messageFormat.setLocale(_locale);
messageFormat.applyPattern(pattern);
return messageFormat.format(args);
}
private String extractMessage(Throwable t)
{
String message = t.getMessage();
return HiveMind.isNonBlank(message) ? message : t.getClass().getName();
}
public String format(String key, Object arg0)
{
return format(key, new Object[] { arg0 });
}
public String format(String key, Object arg0, Object arg1)
{
return format(key, new Object[] { arg0, arg1 });
}
public String format(String key, Object arg0, Object arg1, Object arg2)
{
return format(key, new Object[] { arg0, arg1, arg2 });
}
}