net.sf.ehcache.management.ResourceClassLoader Maven / Gradle / Ivy
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Show all versions of ehcache-core Show documentation
This is the ehcache core module. Pair it with other modules for added functionality.
/**
* Copyright Terracotta, Inc.
*
* 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 net.sf.ehcache.management;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.Manifest;
import java.util.jar.Attributes.Name;
import net.sf.ehcache.util.MergedEnumeration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* ResourceClassLoader can load classes nested in a subdirectory of a jar
* Example :
* ehcache.jar!/net/sf/ehcache/CacheManager is in the "normal" classpath and will be loaded by any typical classloader
* ehcache.jar!/subdirectory/net/sf/ehcache/CacheManager can only be loaded by the ResourceClassLoader, with prefix "subdirectory"
*
* @author Anthony Dahanne
*
*/
public class ResourceClassLoader extends ClassLoader {
private static final int BUFFER_SIZE = 1024;
private static final Logger LOG = LoggerFactory.getLogger(ResourceClassLoader.class);
private final String prefix;
private final String implementationVersion;
/**
* Given a parent classloader and the prefix to apply to the lookup path
* Creates a ResourceClassLoader able to load classes from resources prefixed with "prefix"
*
* @param prefix
* @param parent
* @throws IOException
*/
public ResourceClassLoader(String prefix, ClassLoader parent) {
super(parent);
this.prefix = prefix;
String temporaryImplementationVersion = null;
InputStream in = null;
// looking up the version of our jar, from the Manifest in the private package (prefix)
try {
URL manifestResource = getParent().getResource(prefix + "/META-INF/MANIFEST.MF");
in = manifestResource.openStream();
Manifest man = new Manifest(in);
Attributes attributes = man.getMainAttributes();
temporaryImplementationVersion = attributes.getValue(Name.IMPLEMENTATION_VERSION);
} catch (Exception e) {
LOG.debug("Could not read the Manifest", e);
} finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e) {
/* Ignore */
}
}
this.implementationVersion = temporaryImplementationVersion;
}
@Override
public synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
// changing the order of delegation to prefer the resourceClassLoader over its parents
Class c = findLoadedClass(name);
if (c == null) {
try {
c = findClass(name);
} catch (ClassNotFoundException e) {
c = super.loadClass(name, resolve);
}
}
if (resolve) {
resolveClass(c);
}
return c;
}
@Override
public URL getResource(String name) {
URL url;
url = findResource(name);
if (url == null) {
return super.getResource(name);
}
return url;
}
@Override
protected URL findResource(String name) {
URL resource = getParent().getResource(prefix + "/" + name);
return resource;
}
@Override
/**
* very similar to what OracleJDK classloader does,
* except the first resources (more important) are the ones found with our ResourceClassLoader
*/
public Enumeration getResources(String resourceName) throws IOException {
Enumeration[] tmp = new Enumeration[2];
tmp[0] = findResources(resourceName);
tmp[1] = getParent().getResources(resourceName);
return new MergedEnumeration(tmp[0], tmp[1]);
};
@Override
protected Enumeration findResources(String name) throws IOException {
Enumeration resources = getParent().getResources(prefix + "/" + name);
// DEV-8100 add support for Jboss AS, translating vfs URLs
List urls = new ArrayList();
while (resources.hasMoreElements()) {
URL elementToAdd;
URL nextElement = resources.nextElement();
if (nextElement.toExternalForm().startsWith("vfs")) {
elementToAdd = translateFromVFSToPhysicalURL(nextElement);
} else {
elementToAdd = nextElement;
}
urls.add(elementToAdd);
}
return Collections.enumeration(urls);
}
@Override
protected Class findClass(String className) throws ClassNotFoundException {
String classRealName = prefix + "/" + className.replace('.', '/') + ".class";
URL classResource = getParent().getResource(classRealName);
if (classResource != null) {
// classresource ok, let's define its package too
int index = className.lastIndexOf('.');
if (index != -1) {
String pkgname = className.substring(0, index);
if (getPackage(pkgname) == null) {
definePackage(pkgname, null, null, null, null, implementationVersion, null, null);
}
}
InputStream in = null;
try {
byte[] array = new byte[BUFFER_SIZE];
in = classResource.openStream();
ByteArrayOutputStream out = new ByteArrayOutputStream(array.length);
int length = in.read(array);
while (length > 0) {
out.write(array, 0, length);
length = in.read(array);
}
Class defineClass = defineClass(className, out.toByteArray(), 0, out.size());
return defineClass;
} catch (IOException e) {
LOG.warn("Impossible to open " + classRealName + " for loading", e);
} finally {
try {
if (in != null) {
in.close();
}
} catch (Exception e) {
/* Ignore */
}
}
}
throw new ClassNotFoundException(className);
}
/**
* DEV-8100 add support for Jboss AS
* jersey does not understand Jboss VFS URLs , so we use Jboss VFS classes to translate those URLs to file: URLs
*/
private URL translateFromVFSToPhysicalURL(URL vfsUrl) throws IOException {
URL physicalUrl = null;
URLConnection vfsURLConnection = vfsUrl.openConnection();
Object vfsVirtualFile = vfsURLConnection.getContent();
try {
Class vfsUtilsClass = Class.forName("org.jboss.vfs.VFSUtils");
Class virtualFileClass = Class.forName("org.jboss.vfs.VirtualFile");
Method getPathName = virtualFileClass.getDeclaredMethod("getPathName", new Class[0]);
Method getPhysicalURL = vfsUtilsClass.getDeclaredMethod("getPhysicalURL", virtualFileClass);
Method recursiveCopy = vfsUtilsClass.getDeclaredMethod("recursiveCopy", virtualFileClass, File.class);
String pathName = (String) getPathName.invoke(vfsVirtualFile, (Object[]) null);
physicalUrl = (URL) getPhysicalURL.invoke(null, vfsVirtualFile);
File physicalURLAsFile = new File(physicalUrl.getFile());
// https://issues.jboss.org/browse/JBAS-8786
if (physicalURLAsFile.isDirectory() && physicalURLAsFile.list().length == 0) {
// jboss does not unpack the libs in WEB-INF/lib, we have to unpack them (partially) ourselves
unpackVfsResourceToPhysicalURLLocation(physicalUrl, vfsVirtualFile, recursiveCopy);
}
} catch (ClassNotFoundException e) {
// ignore, jboss-5 and below doesn't have this class
} catch (NoSuchMethodException e) {
throw new RuntimeException(e);
} catch (InvocationTargetException e) {
throw new RuntimeException(e.getCause());
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
} catch (IllegalArgumentException e) {
throw new RuntimeException(e);
}
return physicalUrl;
}
private void unpackVfsResourceToPhysicalURLLocation(URL physicalUrl, Object vfsVirtualFile, Method recursiveCopy)
throws IllegalAccessException, InvocationTargetException {
String physicalPath = physicalUrl.getFile() + "/../";
recursiveCopy.invoke(null, vfsVirtualFile, new File(physicalPath));
}
}
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