com.atlassian.plugin.util

Class ClassLoaderStack

java.lang.Object

com.atlassian.plugin.util.ClassLoaderStack

public class ClassLoaderStack
extends Object

This utility provides a thread local stack of ClassLoaders. The current "top" of the stack is the thread's current context class loader. This can be used when implementing delegating plugin Filters or Servlets that need to set the ClassLoader to the PluginClassLoader the filter or servlet is declared in.

Since:

2.5.0

Constructor Summary

Constructors

Constructor and Description
ClassLoaderStack()

Method Summary

Modifier and Type	Method and Description
static ClassLoader	pop() Pops the current ContextClassLoader off the stack, setting the new ContextClassLoader to the previous one on the stack.
static void	push(ClassLoader loader) Makes the given classLoader the new ContextClassLoader for this thread, and pushes the current ContextClassLoader onto a ThreadLocal stack so that we can do a pop() operation later to return to that ContextClassLoader.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ClassLoaderStack

public ClassLoaderStack()

Method Detail

push

public static void push(ClassLoader loader)

Makes the given classLoader the new ContextClassLoader for this thread, and pushes the current ContextClassLoader onto a ThreadLocal stack so that we can do a pop() operation later to return to that ContextClassLoader.

Passing null is allowed and will act as a no-op. This means that you can safely pop() a ClassLoader and push it back in and it will work safely whether the stack was empty at time of pop() or not.

Parameters:

loader - The new ClassLoader to set as ContextClassLoader.

pop

public static ClassLoader pop()

Pops the current ContextClassLoader off the stack, setting the new ContextClassLoader to the previous one on the stack.

• If the stack is not empty, then the current ClassLoader is replaced by the previous one on the stack, and then returned.
• If the stack is empty, then null is returned and the current ContextClassLoader is not changed.

Returns:

the previous ContextClassLoader that was just replaced, or null if the stack is empty.