org.jboss.util.loading: public class: ContextClassLoaderSwitcher

org.jboss.util.loading
public class: ContextClassLoaderSwitcher [javadoc | source]

java.lang.Object
   org.jboss.util.loading.ContextClassLoader
      org.jboss.util.loading.ContextClassLoaderSwitcher

A helper for context classloading switching.

When a security manager is installed, the constructor checks for the runtime permissions "getClassLoader" and "setContextClassLoader". This allows the methods of this class to be used later without having to run in privileged blocks. There are optimized methods to perform the operations within a switch context. This avoids retrieving the current thread on every operation.

version: < - tt>$Revision: 1.4 $

author: < - a href="mailto:adrian@jboss.org">Adrian Brock

Nested Class Summary:
public class	ContextClassLoaderSwitcher.SwitchContext	A helper class to remember the original classloader and avoid continually retrieveing the current thread.

Field Summary
public static final RuntimePermission	SETCONTEXTCLASSLOADER	Set the context classloader permission
public static final ContextClassLoaderSwitcher.NewInstance	INSTANTIATOR	Instantiate a new context class loader switcher

Fields inherited from org.jboss.util.loading.ContextClassLoader:
GETCLASSLOADER, INSTANTIATOR

Method from org.jboss.util.loading.ContextClassLoaderSwitcher Summary:
getSwitchContext, getSwitchContext, getSwitchContext, setContextClassLoader, setContextClassLoader

Methods from org.jboss.util.loading.ContextClassLoader:
getContextClassLoader, getContextClassLoader

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.jboss.util.loading.ContextClassLoaderSwitcher Detail:
public ContextClassLoaderSwitcher.SwitchContext getSwitchContext() { return new SwitchContext(); } Retrieve a switch context
public ContextClassLoaderSwitcher.SwitchContext getSwitchContext(ClassLoader cl) { return new SwitchContext(cl); } Retrieve a switch context and set the new context classloader
public ContextClassLoaderSwitcher.SwitchContext getSwitchContext(Class clazz) { return new SwitchContext(clazz.getClassLoader()); } Deprecated! `using` - a class to determine the classloader is a bad idea, it has the same problems as Class.forName() Retrieve a switch context for the classloader of a given class
public void setContextClassLoader(ClassLoader cl) { setContextClassLoader(Thread.currentThread(), cl); } Set the context classloader
public void setContextClassLoader(Thread thread, ClassLoader cl) { AccessController.doPrivileged(new PrivilegedAction() { public Object run() { thread.setContextClassLoader(cl); return null; } }); } Set the context classloader for the given thread

Method from org.jboss.util.loading.ContextClassLoaderSwitcher Detail:

 public ContextClassLoaderSwitcher.SwitchContext getSwitchContext() {
      return new SwitchContext();
}

Retrieve a switch context

 public ContextClassLoaderSwitcher.SwitchContext getSwitchContext(ClassLoader cl) {
      return new SwitchContext(cl);
}

Retrieve a switch context and set the new context classloader

 public ContextClassLoaderSwitcher.SwitchContext getSwitchContext(Class clazz) {
      return new SwitchContext(clazz.getClassLoader());
}

Deprecated! using - a class to determine the classloader is a bad idea, it has the same problems as Class.forName()

Retrieve a switch context for the classloader of a given class

 public  void setContextClassLoader(ClassLoader cl) {
      setContextClassLoader(Thread.currentThread(), cl);
}

Set the context classloader

 public  void setContextClassLoader(Thread thread,
    ClassLoader cl) {
      AccessController.doPrivileged(new PrivilegedAction()
      {
         public Object run()
         {
            thread.setContextClassLoader(cl);
            return null;
         }
      });
}

Set the context classloader for the given thread