com.sun.istack.tools.ParallelWorldClassLoader Maven / Gradle / Ivy
Show all versions of jaxb-xjc Show documentation
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2011 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.istack.tools;
import java.io.InputStream;
import java.io.ByteArrayOutputStream;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.net.MalformedURLException;
import java.net.URLConnection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Set;
import java.util.jar.JarFile;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Load classes/resources from a side folder, so that
* classes of the same package can live in a single jar file.
*
*
* For example, with the following jar file:
*
* /
* +- foo
* +- X.class
* +- bar
* +- X.class
*
*
* {@link ParallelWorldClassLoader}("foo/") would load X.class from
* /foo/X.class (note that X is defined in the root package, not
* foo.X.
*
*
* This can be combined with {@link MaskingClassLoader} to mask classes which are loaded by the parent
* class loader so that the child class loader
* classes living in different folders are loaded
* before the parent class loader loads classes living the jar file publicly
* visible
* For example, with the following jar file:
*
* /
* +- foo
* +- X.class
* +- bar
* +-foo
* +- X.class
*
*
* {@link ParallelWorldClassLoader}(MaskingClassLoader.class.getClassLoader()) would load foo.X.class from
* /bar/foo.X.class not the foo.X.class in the publicly visible place in the jar file, thus
* masking the parent classLoader from loading the class from foo.X.class
* (note that X is defined in the package foo, not
* bar.foo.X.
*
* @author Kohsuke Kawaguchi
*/
public class ParallelWorldClassLoader extends ClassLoader implements Closeable {
/**
* Strings like "prefix/", "abc/", or "" to indicate
* classes should be loaded normally.
*/
private final String prefix;
private final Set jars;
public ParallelWorldClassLoader(ClassLoader parent,String prefix) {
super(parent);
this.prefix = prefix;
jars = Collections.synchronizedSet(new HashSet());
}
protected Class findClass(String name) throws ClassNotFoundException {
StringBuffer sb = new StringBuffer(name.length()+prefix.length()+6);
sb.append(prefix).append(name.replace('.','/')).append(".class");
URL u = getParent().getResource(sb.toString());
if (u == null) {
throw new ClassNotFoundException(name);
}
InputStream is = null;
URLConnection con = null;
try {
con = u.openConnection();
is = con.getInputStream();
} catch (IOException ioe) {
throw new ClassNotFoundException(name);
}
if (is==null)
throw new ClassNotFoundException(name);
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[1024];
int len;
while((len=is.read(buf))>=0)
baos.write(buf,0,len);
buf = baos.toByteArray();
int packIndex = name.lastIndexOf('.');
if (packIndex != -1) {
String pkgname = name.substring(0, packIndex);
// Check if package already loaded.
Package pkg = getPackage(pkgname);
if (pkg == null) {
definePackage(pkgname, null, null, null, null, null, null, null);
}
}
return defineClass(name,buf,0,buf.length);
} catch (IOException e) {
throw new ClassNotFoundException(name,e);
} finally {
try {
if (con != null && con instanceof JarURLConnection) {
jars.add(((JarURLConnection) con).getJarFile());
}
} catch (IOException ioe) {
//ignore
}
if (is != null) {
try {
is.close();
} catch (IOException ioe) {
//ignore
}
}
}
}
@Override
protected URL findResource(String name) {
URL u = getParent().getResource(prefix + name);
if (u != null) {
try {
jars.add(new JarFile(new File(toJarUrl(u).toURI())));
} catch (URISyntaxException ex) {
Logger.getLogger(ParallelWorldClassLoader.class.getName()).log(Level.WARNING, null, ex);
} catch (IOException ex) {
Logger.getLogger(ParallelWorldClassLoader.class.getName()).log(Level.WARNING, null, ex);
} catch (ClassNotFoundException ex) {
//ignore - not a jar
}
}
return u;
}
@Override
protected Enumeration findResources(String name) throws IOException {
Enumeration en = getParent().getResources(prefix + name);
while (en.hasMoreElements()) {
try {
jars.add(new JarFile(new File(toJarUrl(en.nextElement()).toURI())));
} catch (URISyntaxException ex) {
//should not happen
Logger.getLogger(ParallelWorldClassLoader.class.getName()).log(Level.WARNING, null, ex);
} catch (IOException ex) {
Logger.getLogger(ParallelWorldClassLoader.class.getName()).log(Level.WARNING, null, ex);
} catch (ClassNotFoundException ex) {
//ignore - not a jar
}
}
return en;
}
public synchronized void close() throws IOException {
for (JarFile jar : jars) {
jar.close();
}
}
/**
* Given the URL inside jar, returns the URL to the jar itself.
*/
public static URL toJarUrl(URL res) throws ClassNotFoundException, MalformedURLException {
String url = res.toExternalForm();
if(!url.startsWith("jar:"))
throw new ClassNotFoundException("Loaded outside a jar "+url);
url = url.substring(4); // cut off jar:
url = url.substring(0,url.lastIndexOf('!')); // cut off everything after '!'
return new URL(url);
}
}