mymsg.java

pastry的java实现的2.0b版

/*************************************************************************

"FreePastry" Peer-to-Peer Application Development Substrate 

Copyright 2002, Rice University. All rights reserved.

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********************************************************************************/
/*
 *  Created on Feb 15, 2005
 */
package rice.tutorial.rawserialization;

import java.io.IOException;

import rice.p2p.commonapi.*;
import rice.p2p.commonapi.rawserialization.*;

/**
 * An example message.
 *
 * @version $Id: pretty.settings 2305 2005-03-11 20:22:33Z jeffh $
 * @author Jeff Hoye
 */
public class MyMsg implements RawMessage {

  /**
   * Where the Message came from.
   */
  Id from;
  /**
   * Where the Message is going.
   */
  Id to;
  /**
   * DESCRIBE THE FIELD
   */
  protected final static short TYPE = 1;

  /**
   * Constructor.
   *
   * @param from DESCRIBE THE PARAMETER
   * @param to DESCRIBE THE PARAMETER
   */
  public MyMsg(Id from, Id to) {
    this.from = from;
    this.to = to;
  }

  /**
   * Constructor for MyMsg.
   *
   * @param buf DESCRIBE THE PARAMETER
   * @param endpoint DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public MyMsg(InputBuffer buf, Endpoint endpoint) throws IOException {
    from = endpoint.readId(buf, buf.readShort());
    to = endpoint.readId(buf, buf.readShort());
  }

  /**
   * Use low priority to prevent interference with overlay maintenance traffic.
   *
   * @return The Priority value
   */
  public byte getPriority() {
    return Message.LOW_PRIORITY;
  }

  /**
   * Gets the Type attribute of the MyMsg object
   *
   * @return The Type value
   */
  public short getType() {
    return TYPE;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @return DESCRIBE THE RETURN VALUE
   */
  public String toString() {
    return "MyMsg from " + from + " to " + to;
  }

  /**
   * DESCRIBE THE METHOD
   *
   * @param buf DESCRIBE THE PARAMETER
   * @exception IOException DESCRIBE THE EXCEPTION
   */
  public void serialize(OutputBuffer buf) throws IOException {
    buf.writeShort(from.getType());
    from.serialize(buf);
    buf.writeShort(to.getType());
    to.serialize(buf);
  }
}