dispatchproxy.java

用java和windows的word应用的通用编程接口 关联起来

/*
 * Copyright (c) 1999-2004 Sourceforge JACOB Project.
 * All rights reserved. Originator: Dan Adler (http://danadler.com).
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution. 
 * 3. Redistributions in any form must be accompanied by information on
 *    how to obtain complete source code for the JACOB software.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package com.jacob.com;

/**
 * If you need to pass a COM Dispatch object between STA threads, you have to
 * marshall the interface. This class is used as follows: the STA that creates
 * the Dispatch object must construct an instance of this class. Another thread
 * can then call toDispatch() on that instance and get a Dispatch pointer which
 * has been marshalled. WARNING: You can only call toDispatch() once! If you
 * need to call it multiple times (or from multiple threads) you need to
 * construct a separate DispatchProxy instance for each such case!
 */
public class DispatchProxy extends JacobObject {
    /**
     * Comment for <code>m_pStream</code>
     */
    public int m_pStream;

    /**
     * Marshals the passed in dispatch into the stream
     * @param localDispatch
     */
    public DispatchProxy(Dispatch localDispatch) {
        MarshalIntoStream(localDispatch);
    }

    /**
     * 
     * @return Dispatch the dispatch retrieved from the stream
     */
    public Dispatch toDispatch() {
        return MarshalFromStream();
    }

    private native void MarshalIntoStream(Dispatch d);

    private native Dispatch MarshalFromStream();

    /**
     *  now private so only this object can asccess
     *  was: call this to explicitly release the com object before gc
     * 
     */
    private native void release();

    /* (non-Javadoc)
     * @see java.lang.Object#finalize()
     */
    public void finalize() {
        safeRelease();
    }
    
    /*
     *  (non-Javadoc)
     * @see com.jacob.com.JacobObject#safeRelease()
     */
    public void safeRelease()
    {
        super.safeRelease();
        if (m_pStream != 0){
            release();
            m_pStream = 0;
        } else {
            // looks like a double release
            if (isDebugEnabled()){debug(this.getClass().getName()+":"+this.hashCode()+" double release");}
        }
    }
}