/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.tomcat.util.res;
import java.text.MessageFormat;
import java.util.Hashtable;
import java.util.Locale;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
/**
* An internationalization / localization helper class which reduces
* the bother of handling ResourceBundles and takes care of the
* common cases of message formating which otherwise require the
* creation of Object arrays and such.
*
* <p>The StringManager operates on a package basis. One StringManager
* per package can be created and accessed via the getManager method
* call.
*
* <p>The StringManager will look for a ResourceBundle named by
* the package name given plus the suffix of "LocalStrings". In
* practice, this means that the localized information will be contained
* in a LocalStrings.properties file located in the package
* directory of the classpath.
*
* <p>Please see the documentation for java.util.ResourceBundle for
* more information.
*
* @version $Revision: 466585 $ $Date: 2006-10-21 23:16:34 +0100 (Sat, 21 Oct 2006) $
*
* @author James Duncan Davidson [duncan@eng.sun.com]
* @author James Todd [gonzo@eng.sun.com]
* @author Mel Martinez [mmartinez@g1440.com]
* @see java.util.ResourceBundle
*/
public class StringManager {
/**
* The ResourceBundle for this StringManager.
*/
private ResourceBundle bundle;
private Locale locale;
/**
* Creates a new StringManager for a given package. This is a
* private method and all access to it is arbitrated by the
* static getManager method call so that only one StringManager
* per package will be created.
*
* @param packageName Name of package to create StringManager for.
*/
private StringManager(String packageName) {
this( packageName, Locale.getDefault() );
}
private StringManager(String packageName, Locale loc) {
String bundleName = packageName + ".LocalStrings";
bundle = ResourceBundle.getBundle(bundleName, loc);
// Get the actual locale, which may be different from the requested one
locale = bundle.getLocale();
}
private StringManager(ResourceBundle bundle )
{
this.bundle=bundle;
locale = bundle.getLocale();
}
/**
Get a string from the underlying resource bundle or return
null if the String is not found.
@param key to desired resource String
@return resource String matching <i>key</i> from underlying
bundle or null if not found.
@throws IllegalArgumentException if <i>key</i> is null.
*/
public String getString(String key) {
if(key == null){
String msg = "key may not have a null value";
throw new IllegalArgumentException(msg);
}
String str = null;
try{
str = bundle.getString(key);
}catch(MissingResourceException mre){
//bad: shouldn't mask an exception the following way:
// str = "[cannot find message associated with key '" + key + "' due to " + mre + "]";
// because it hides the fact that the String was missing
// from the calling code.
//good: could just throw the exception (or wrap it in another)
// but that would probably cause much havoc on existing
// code.
//better: consistent with container pattern to
// simply return null. Calling code can then do
// a null check.
str = null;
}
return str;
}
/**
* Get a string from the underlying resource bundle and format
* it with the given set of arguments.
*
* @param key
* @param args
*/
public String getString(String key, Object[] args) {
String iString = null;
String value = getString(key);
// this check for the runtime exception is some pre 1.1.6
// VM's don't do an automatic toString() on the passed in
// objects and barf out
try {
// ensure the arguments are not null so pre 1.2 VM's don't barf
if(args==null){
args = new Object[1];
}
Object[] nonNullArgs = args;
for (int i=0; i<args.length; i++) {
if (args[i] == null) {
if (nonNullArgs==args){
nonNullArgs=(Object[])args.clone();
}
nonNullArgs[i] = "null";
}
}
if( value==null ) value=key;
MessageFormat mf = new MessageFormat(value);
mf.setLocale(locale);
iString = mf.format(nonNullArgs, new StringBuffer(), null).toString();
} catch (IllegalArgumentException iae) {
StringBuffer buf = new StringBuffer();
buf.append(value);
for (int i = 0; i < args.length; i++) {
buf.append(" arg[" + i + "]=" + args[i]);
}
iString = buf.toString();
}
return iString;
}
/**
* Get a string from the underlying resource bundle and format it
* with the given object argument. This argument can of course be
* a String object.
*
* @param key
* @param arg
*/
public String getString(String key, Object arg) {
Object[] args = new Object[] {arg};
return getString(key, args);
}
/**
* Get a string from the underlying resource bundle and format it
* with the given object arguments. These arguments can of course
* be String objects.
*
* @param key
* @param arg1
* @param arg2
*/
public String getString(String key, Object arg1, Object arg2) {
Object[] args = new Object[] {arg1, arg2};
return getString(key, args);
}
/**
* Get a string from the underlying resource bundle and format it
* with the given object arguments. These arguments can of course
* be String objects.
*
* @param key
* @param arg1
* @param arg2
* @param arg3
*/
public String getString(String key, Object arg1, Object arg2,
Object arg3) {
Object[] args = new Object[] {arg1, arg2, arg3};
return getString(key, args);
}
/**
* Get a string from the underlying resource bundle and format it
* with the given object arguments. These arguments can of course
* be String objects.
*
* @param key
* @param arg1
* @param arg2
* @param arg3
* @param arg4
*/
public String getString(String key, Object arg1, Object arg2,
Object arg3, Object arg4) {
Object[] args = new Object[] {arg1, arg2, arg3, arg4};
return getString(key, args);
}
// --------------------------------------------------------------
// STATIC SUPPORT METHODS
// --------------------------------------------------------------
private static Hashtable managers = new Hashtable();
/**
* Get the StringManager for a particular package. If a manager for
* a package already exists, it will be reused, else a new
* StringManager will be created and returned.
*
* @param packageName The package name
*/
public synchronized static StringManager getManager(String packageName) {
StringManager mgr = (StringManager)managers.get(packageName);
if (mgr == null) {
mgr = new StringManager(packageName);
managers.put(packageName, mgr);
}
return mgr;
}
/**
* Get the StringManager for a particular package. If a manager for
* a package already exists, it will be reused, else a new
* StringManager will be created and returned.
*
* @param bundle The resource bundle
*/
public synchronized static StringManager getManager(ResourceBundle bundle) {
return new StringManager( bundle );
}
/**
* Get the StringManager for a particular package and Locale. If a manager for
* a package already exists, it will be reused, else a new
* StringManager will be created for that Locale and returned.
*
* @param packageName The package name
* @param loc The locale
*/
public synchronized static StringManager getManager(String packageName,Locale loc) {
StringManager mgr = (StringManager)managers.get(packageName+"_"+loc.toString());
if (mgr == null) {
mgr = new StringManager(packageName,loc);
managers.put(packageName+"_"+loc.toString(), mgr);
}
return mgr;
}
}
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