/*
* JBoss, Home of Professional Open Source.
* Copyright 2011, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.jpa.classloader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Enumeration;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
import org.jboss.modules.ConcurrentClassLoader;
/**
* Return a new instance of a ClassLoader that the may be used to temporarily load any classes,
* resources, or open URLs. None of the classes loaded by this class loader will be visible to
* application components.
* <p/>
* TempClassLoader is suitable for implementing javax.persistence.spi.PersistenceUnitInfo.getNewTempClassLoader()
* <p/>
*
* @author Scott Marlow
* @author Antti Laisi
*/
public class TempClassLoader extends ConcurrentClassLoader {
private final ClassLoader delegate;
private static final String MANIFEST_MF = "META-INF" + File.separatorChar + "MANIFEST.MF";
static {
try {
ClassLoader.registerAsParallelCapable();
} catch (Throwable ignored) {}
}
TempClassLoader(final ClassLoader delegate) {
super((ConcurrentClassLoader) null);
this.delegate = delegate;
}
@Override
protected Class<?> findClass(String name, boolean exportsOnly, boolean resolve) throws ClassNotFoundException {
Class<?> loaded = findLoadedClass(name);
if (loaded != null) {
return loaded;
}
// javax.persistence classes must be loaded by module classloader, otherwise
// the persistence provider can't read JPA annotations with reflection
if (name.startsWith("javax.")) {
return Class.forName(name, resolve, delegate);
}
InputStream resource = delegate.getResourceAsStream(name.replace('.', '/') + ".class");
if (resource == null) {
throw new ClassNotFoundException(name);
}
// Ensure that the package is loaded
final int lastIdx = name.lastIndexOf('.');
if (lastIdx != -1) {
// there's a package name; get the Package for it
final String packageName = name.substring(0, lastIdx);
synchronized (this) {
Package pkg = findLoadedPackage(packageName);
if (pkg == null) {
Manifest manifest = readManifestFile();
if (manifest != null) {
final Attributes mainAttribute = manifest.getMainAttributes();
final Attributes entryAttribute = manifest.getAttributes(packageName);
URL url =
"true".equals(getDefinedAttribute(Attributes.Name.SEALED, entryAttribute, mainAttribute))
? delegate.getResource(name.replace('.', '/') + ".class") : null;
definePackage(
packageName,
getDefinedAttribute(Attributes.Name.SPECIFICATION_TITLE, entryAttribute, mainAttribute),
getDefinedAttribute(Attributes.Name.SPECIFICATION_VERSION, entryAttribute, mainAttribute),
getDefinedAttribute(Attributes.Name.SPECIFICATION_VENDOR, entryAttribute, mainAttribute),
getDefinedAttribute(Attributes.Name.IMPLEMENTATION_TITLE, entryAttribute, mainAttribute),
getDefinedAttribute(Attributes.Name.IMPLEMENTATION_VERSION, entryAttribute, mainAttribute),
getDefinedAttribute(Attributes.Name.IMPLEMENTATION_VENDOR, entryAttribute, mainAttribute),
url
);
}
else {
definePackage(packageName, null, null, null, null, null, null, null);
}
}
}
}
ByteArrayOutputStream baos = new ByteArrayOutputStream();
try {
byte[] buffer = new byte[1024];
for (int i = 0; (i = resource.read(buffer, 0, buffer.length)) != -1; ) {
baos.write(buffer, 0, i);
}
buffer = baos.toByteArray();
return defineClass(name, buffer, 0, buffer.length);
} catch (IOException e) {
throw new ClassNotFoundException(name, e);
} finally {
try {
resource.close();
} catch (IOException e) {
// ignore
}
}
}
@Override
protected URL findResource(String name, boolean exportsOnly) {
return delegate.getResource(name);
}
@Override
protected Enumeration<URL> findResources(String name, boolean exportsOnly) throws IOException {
return delegate.getResources(name);
}
@Override
protected InputStream findResourceAsStream(String name, boolean exportsOnly) {
return delegate.getResourceAsStream(name);
}
/** {@inheritDoc} */
@Override
protected final Package definePackage(final String name, final String specTitle, final String specVersion, final String specVendor, final String implTitle, final String implVersion, final String implVendor, final URL sealBase) throws IllegalArgumentException {
return super.definePackage(name, specTitle, specVersion, specVendor, implTitle, implVersion, implVendor, sealBase);
}
private Manifest readManifestFile() {
InputStream resource = null;
try {
resource = delegate.getResourceAsStream(MANIFEST_MF);
return resource != null ? new Manifest(resource) : null;
} catch (IOException e) {
return null;
}
finally {
if ( resource != null) {
try {
resource.close();
} catch (IOException ignored) {
}
}
}
}
private static String getDefinedAttribute(Attributes.Name name, Attributes entryAttribute, Attributes mainAttribute) {
final String value = entryAttribute == null ? null : entryAttribute.getValue(name);
return value == null ? mainAttribute == null ? null : mainAttribute.getValue(name) : value;
}
}