org.apache.ws.security.util.Loader Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of wss4j Show documentation
Show all versions of wss4j Show documentation
The Apache WSS4J project provides a Java implementation of the primary security standards
for Web Services, namely the OASIS Web Services Security (WS-Security) specifications
from the OASIS Web Services Security TC.
/**
* 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.ws.security.util;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.lang.reflect.InvocationTargetException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
/**
* Load resources (or images) from various sources.
*
*
* @author Davanum Srinivas ([email protected]).
*/
public class Loader {
private static Log log = LogFactory.getLog(Loader.class.getName());
/**
* This method will search for resource in different
* places. The search order is as follows:
*
* - Search for
resource using the thread context
* class loader under Java2.
* - Try one last time with
*
ClassLoader.getSystemResource(resource), that is is
* using the system class loader in JDK 1.2 and virtual machine's
* built-in class loader in JDK 1.1.
*
*
*
* @param resource
* @return TODO
*/
public static URL getResource(String resource) {
ClassLoader classLoader = null;
URL url = null;
try {
classLoader = getTCL();
if (classLoader != null) {
log.debug("Trying to find [" + resource + "] using " + classLoader + " class loader.");
url = classLoader.getResource(resource);
if (url != null) {
return url;
}
}
} catch (Throwable t) {
log.warn("Caught Exception while in Loader.getResource. This may be innocuous.", t);
}
// Last ditch attempt: get the resource from the class path. It
// may be the case that clazz was loaded by the Extension class
// loader which the parent of the system class loader. Hence the
// code below.
log.debug("Trying to find [" + resource + "] using ClassLoader.getSystemResource().");
return ClassLoader.getSystemResource(resource);
}
/**
* This method will search for resource in different
* places. The search order is as follows:
*
* - Search for
resource using the supplied class loader.
* If that fails, search for resource using the thread context
* class loader.
* - Try one last time with
*
ClassLoader.getSystemResource(resource), that is is
* using the system class loader in JDK 1.2 and virtual machine's
* built-in class loader in JDK 1.1.
*
*
*
* @param resource
* @return TODO
*/
public static URL getResource(ClassLoader loader, String resource) {
URL url = null;
try {
if (loader != null) {
log.debug("Trying to find [" + resource + "] using " + loader + " class loader.");
url = loader.getResource(resource);
if (url != null) {
return url;
}
}
} catch (Throwable t) {
log.warn("Caught Exception while in Loader.getResource. This may be innocuous.", t);
}
return getResource(resource);
}
/**
* Get the Thread context class loader.
*
*
* @return the Thread context class loader
* @throws IllegalAccessException
* @throws InvocationTargetException
*/
public static ClassLoader getTCL() throws IllegalAccessException, InvocationTargetException {
return (ClassLoader)AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
return Thread.currentThread().getContextClassLoader();
}
});
}
/**
* Get the class loader of the class argument
*
*
* @return the class loader of the argument
*/
public static ClassLoader getClassLoader(final Class clazz) {
return (ClassLoader)AccessController.doPrivileged(new PrivilegedAction() {
public Object run() {
return clazz.getClassLoader();
}
});
}
/**
* Try the specified classloader and then fall back to the loadClass
*
*
* @param loader
* @param clazz
* @return Class
* @throws ClassNotFoundException
*/
public static Class loadClass(ClassLoader loader, String clazz) throws ClassNotFoundException {
try {
if (loader != null) {
Class c = loader.loadClass(clazz);
if (c != null) {
return c;
}
}
} catch (Throwable e) {
log.warn(e.getMessage(), e);
}
return loadClass(clazz, true);
}
/**
* If running under JDK 1.2 load the specified class using the
* Thread contextClassLoader if that
* fails try Class.forname.
*
*
* @param clazz
* @return TODO
* @throws ClassNotFoundException
*/
public static Class loadClass(String clazz) throws ClassNotFoundException {
return loadClass(clazz, true);
}
public static Class loadClass(String clazz, boolean warn) throws ClassNotFoundException {
try {
ClassLoader tcl = getTCL();
if (tcl != null) {
Class c = tcl.loadClass(clazz);
if (c != null) {
return c;
}
}
} catch (Throwable e) {
if (warn) {
log.warn(e.getMessage(), e);
} else {
log.debug(e.getMessage(), e);
}
}
// we reached here because tcl was null or because of a
// security exception, or because clazz could not be loaded...
// In any case we now try one more time
return Class.forName(clazz);
}
}