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The Fedora Client is a Java Library that allows API access to a Fedora Repository. The client is typically one part of a full Fedora installation.

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/*
 * -----------------------------------------------------------------------------
 *
 * 

License and Copyright: The contents of this file are subject to 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.fedora-commons.org/licenses.

* *

Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for * the specific language governing rights and limitations under the License.

* *

The entire file consists of original code.

*

Copyright © 2008 Fedora Commons, Inc.
*

Copyright © 2002-2007 The Rector and Visitors of the University of * Virginia and Cornell University
* All rights reserved.

* * ----------------------------------------------------------------------------- */ package fedora.client; import java.util.HashMap; import javax.swing.SwingUtilities; /** * This is the 3rd version of SwingWorker (also known as * SwingWorker 3), an abstract class that you subclass to * perform GUI-related work in a dedicated thread. For * instructions on and examples of using this class, see: * * http://java.sun.com/docs/books/tutorial/uiswing/misc/threads.html * * Note that the API changed slightly in the 3rd version: * You must now invoke start() on the SwingWorker after * creating it. */ public abstract class SwingWorker { private Object value; // see getValue(), setValue() public boolean done; // set to true only upon finish public Exception thrownException; /** * Class to maintain reference to current worker thread * under separate synchronization control. */ private static class ThreadVar { private Thread thread; ThreadVar(Thread t) { thread = t; } synchronized Thread get() { return thread; } synchronized void clear() { thread = null; } } private ThreadVar threadVar; /** * Get the value produced by the worker thread, or null if it * hasn't been constructed yet. */ protected synchronized Object getValue() { return value; } /** * Set the value produced by worker thread */ public synchronized void setValue(Object x) { value = x; } /** * Compute the value to be returned by the get method. */ public abstract Object construct(); /** * Called on the event dispatching thread (not on the worker thread) * after the construct method has returned. */ public void finished() { done=true; } /** * A new method that interrupts the worker thread. Call this method * to force the worker to stop what it's doing. */ public void interrupt() { Thread t = threadVar.get(); if (t != null) { t.interrupt(); } threadVar.clear(); } /** * Return the value created by the construct method. * Returns null if either the constructing thread or the current * thread was interrupted before a value was produced. * * @return the value created by the construct method */ public Object get() { while (true) { Thread t = threadVar.get(); if (t == null) { return getValue(); } try { t.join(); } catch (InterruptedException e) { Thread.currentThread().interrupt(); // propagate return null; } } } public HashMap parms; /** * Start a thread that will call the construct method * and then exit. */ public SwingWorker(HashMap parms) { this.parms=parms; final Runnable doFinished = new Runnable() { public void run() { finished(); } }; Runnable doConstruct = new Runnable() { public void run() { try { setValue(construct()); } finally { threadVar.clear(); } done=true; SwingUtilities.invokeLater(doFinished); } }; Thread t = new Thread(doConstruct); threadVar = new ThreadVar(t); } /** * Start the worker thread. */ public void start() { Thread t = threadVar.get(); if (t != null) { t.start(); } } }




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