| /* |
| * Copyright 1999-2004 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.garbage.serializer.encoding; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.File; |
| import java.io.PrintWriter; |
| import java.io.PrintStream; |
| import java.io.IOException; |
| import java.io.OutputStreamWriter; |
| import java.io.UnsupportedEncodingException; |
| import java.net.URL; |
| import java.util.Enumeration; |
| import java.util.HashMap; |
| import java.util.zip.ZipEntry; |
| import java.util.zip.ZipFile; |
| |
| /** |
| * |
| * |
| * @author <a href="mailto:pier@apache.org">Pier Fumagalli</a>, February 2003 |
| * @version CVS $Id: CharsetFactory.java,v 1.2 2004/03/05 10:07:22 bdelacretaz Exp $ |
| */ |
| public final class CharsetFactory { |
| |
| /** Our private instance. */ |
| private static CharsetFactory instance = new CharsetFactory(); |
| |
| /** The instance of the JVM default <code>Charset</code>. */ |
| private Charset defaultCharset = null; |
| |
| /** The instance of the JVM unknown <code>Charset</code>. */ |
| private Charset unknownCharset = null; |
| |
| /** All our charsets, mapped by their name and aliases. */ |
| private HashMap charsets = new HashMap(); |
| |
| /** |
| * Create a new instance of this <code>CharsetFactory</code>. |
| */ |
| private CharsetFactory() { |
| super(); |
| this.unknownCharset = new UnknownCharset(); |
| |
| ClassLoader loader = this.getClass().getClassLoader(); |
| String file = this.getClass().getName().replace('.','/') + ".class"; |
| URL url = loader.getResource(file); |
| |
| if ("jar".equals(url.getProtocol())) { |
| this.loadCharsetsFromJar(url); |
| } else if ("file".equals(url.getProtocol())) { |
| this.loadCharsetsFromFile(url); |
| } else { |
| throw new CharsetFactoryException("Unable to load charsets " + |
| "from protocol \"" + url.getProtocol() + "\"", null); |
| } |
| |
| ByteArrayOutputStream otmp = new ByteArrayOutputStream(); |
| OutputStreamWriter wtmp = new OutputStreamWriter(otmp); |
| String etmp = wtmp.getEncoding(); |
| try { |
| defaultCharset = this.getCharset(etmp); |
| } catch (UnsupportedEncodingException exception) { |
| throw new CharsetFactoryException("The default encoding of this " |
| + "JVM \"" + etmp + "\" is not supported", exception); |
| } |
| |
| } |
| |
| /** |
| * Load a <code>Charset</code> into this factory. |
| */ |
| private void loadCharset(Charset charset) { |
| this.charsets.put(charset.getName().toLowerCase(), charset); |
| String aliases[] = charset.getAliases(); |
| for (int x = 0; x < aliases.length; x++) { |
| this.charsets.put(aliases[x].toLowerCase(), charset); |
| } |
| } |
| |
| /** |
| * Instantiate and load a <code>Charset</code> into this factory. |
| */ |
| private void loadCharset(String clazz) { |
| try { |
| Class c = Class.forName(clazz); |
| Object o = c.newInstance(); |
| if (o instanceof Charset) { |
| loadCharset((Charset)o); |
| } |
| } catch (Exception exception) { |
| throw new CharsetFactoryException("Unable to instantiate class \"" |
| + clazz + "\"", exception); |
| } |
| } |
| |
| /** |
| * Load all <code>Charset</code> available if this class was loaded |
| * from a JAR file. |
| */ |
| private void loadCharsetsFromJar(URL url) { |
| try { |
| String file = url.getFile(); |
| String mtch = file.substring(file.indexOf('!')); |
| file = file.substring(5, file.indexOf('!')); |
| mtch = mtch.substring(2, mtch.lastIndexOf('/') + 1) + "cs_"; |
| |
| ZipFile zip = new ZipFile(file); |
| Enumeration enum = zip.entries(); |
| while (enum.hasMoreElements()) { |
| ZipEntry entry = (ZipEntry)enum.nextElement(); |
| String name = entry.getName(); |
| if ((! name.startsWith(mtch)) || |
| (! name.endsWith(".class"))) continue; |
| name = name.substring(mtch.length()); |
| name = ".cs_" + name.substring(0, name.length() - 6); |
| name = this.getClass().getPackage().getName() + name; |
| loadCharset(name); |
| } |
| } catch (IOException exception) { |
| throw new CharsetFactoryException("Unable to access JAR \"" |
| + url.toString() + "\"", exception); |
| } |
| } |
| |
| /** |
| * Load all <code>Charset</code> available if this class was loaded |
| * from a plain file on disk. |
| */ |
| private void loadCharsetsFromFile(URL url) { |
| File file = new File(url.getFile()).getParentFile(); |
| String children[] = file.list(); |
| for (int x = 0; x < children.length; x++) { |
| String child = children[x]; |
| if ((! child.startsWith("cs_")) || |
| (! child.endsWith(".class"))) continue; |
| child = '.' + child.substring(0, child.length() - 6); |
| child = this.getClass().getPackage().getName() + child; |
| this.loadCharset(child); |
| } |
| } |
| |
| /** |
| * Return an instance of this <code>CharsetFactory</code>. |
| */ |
| public static CharsetFactory newInstance() { |
| if (instance != null) return (instance); |
| synchronized (CharsetFactory.class) { |
| if (instance != null) return (instance); |
| instance = new CharsetFactory(); |
| } |
| return(instance); |
| } |
| |
| /** |
| * Return the <code>Charset</code> instance for the unknown charset. |
| * <br /> |
| * All calls to the <code>allows(...)</code> method of the returned |
| * <code>Charset</code> will return <b>true</b>. |
| */ |
| public Charset getCharset() { |
| return(unknownCharset); |
| } |
| |
| /** |
| * Return the <code>Charset</code> instance for the default charset. |
| * |
| * @throws UnsupportedEncodingException If the default is invalid or |
| * cannot be accessed. |
| */ |
| public Charset getDefaultCharset() { |
| return(defaultCharset); |
| } |
| |
| /** |
| * Return the <code>Charset</code> instance for a specifc charset. |
| * |
| * @throws UnsupportedEncodingException If the specified is invalid or |
| * cannot be accessed. |
| */ |
| public Charset getCharset(String name) |
| throws UnsupportedEncodingException { |
| if (name == null) return(this.getDefaultCharset()); |
| Charset charset = (Charset)this.charsets.get(name.toLowerCase()); |
| if (charset != null) return(charset); |
| throw new UnsupportedEncodingException("Unsupported charset \"" |
| + name + "\""); |
| } |
| |
| /** |
| * An <code>RuntimeException</code> thrown if something bad happens |
| * while initializing our factory. |
| */ |
| private static class CharsetFactoryException extends RuntimeException { |
| |
| /** The root cause of this exception. */ |
| private Exception exception = null; |
| |
| /** |
| * Create a new <code>CharsetFactoryException</code> instance. |
| */ |
| private CharsetFactoryException(String message, Exception exception) { |
| super(message == null? exception.getMessage(): message); |
| this.exception = exception; |
| } |
| |
| /** |
| * Return the <code>Exception</code> cause of this exception. |
| */ |
| public Exception getException() { |
| return(this.exception); |
| } |
| |
| /** |
| * Print this <code>Exception</code> stacktrace to a specified |
| * <code>PrintWriter</code>. |
| */ |
| public void printStackTrace(PrintWriter out) { |
| super.printStackTrace(out); |
| if (this.exception != null) { |
| out.print("Root cause: "); |
| this.exception.printStackTrace(out); |
| } |
| } |
| |
| /** |
| * Print this <code>Exception</code> stacktrace to a specified |
| * <code>PrintStream</code>. |
| */ |
| public void printStackTrace(PrintStream out) { |
| super.printStackTrace(out); |
| if (this.exception != null) { |
| out.print("Root cause: "); |
| this.exception.printStackTrace(out); |
| } |
| } |
| } |
| } |