sta.java

java 与COM组件的连接桥

/*
 * Copyright (c) 1999-2004 Sourceforge JACOB Project.
 * All rights reserved. Originator: Dan Adler (http://danadler.com).
 * Get more information about JACOB at http://sourceforge.net/projects/jacob-project
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package com.jacob.com;

/**
 * A class that implements a Single Threaded Apartment. Users will subclass this
 * and override OnInit() and OnQuit() where they will create and destroy a COM
 * component that wants to run in an STA other than the main STA.
 */
public class STA extends Thread {
    /**
     * referenced by STA.cpp
     */
    public int threadID;

    /**
     * constructor for STA
     */
    public STA() {
        start(); // start the thread
    }

    /* (non-Javadoc)
     * @see java.lang.Thread#run()
     */
    public void run() {
        // init COM
        ComThread.InitSTA();
        if (OnInit()) {
            // this call blocks in the win32 message loop
            // until quitMessagePump is called
            doMessagePump();
        }
        OnQuit();
        // uninit COM
        ComThread.Release();
    }

    /**
     * Override this method to create and initialize any COM component that you
     * want to run in this thread. If anything fails, return false to terminate
     * the thread.
     * @return always returns true
     */
    public boolean OnInit() {
        return true;
    }

    /**
     * Override this method to destroy any resource before the thread exits and
     * COM in uninitialized
     */
    public void OnQuit() {
        // there is nothing to see here
    }

    /**
     * calls quitMessagePump
     */
    public void quit() {
        quitMessagePump();
    }

    /**
     * run a message pump for the main STA
     */
    public native void doMessagePump();

    /**
     * quit message pump for the main STA
     */
    public native void quitMessagePump();

    /**
     * STA isn't a subclass of JacobObject so a reference to it doesn't load
     * the DLL without this
     */
    static {
    	LibraryLoader.loadJacobLibrary();
    }
}