dhtapplication.java

p2p仿真器。开发者可以工作在覆盖层中进行创造和测试逻辑算法或者创建和测试新的服务。PlanetSim还可以将仿真代码平稳转换为在Internet上的实验代码

package planet.test.broadcast;

import planet.commonapi.*;
import planet.commonapi.exception.InitializationException;
import planet.generic.commonapi.factory.GenericFactory;

import java.util.*;

/**
 * @author Carles Pairot   <[e-mail]>
 * @author Jordi Pujol     <[e-mail]>
 * @version 1.0
 */
public class DHTApplication implements Application {
  private Properties store = null;
  private EndPoint endPoint = null;
  /**
   * Identification of the application.
   */
  public static String applicationId= "DHTApplication";
  /**
   * Identification of the application instance.
   */
  private String appId = applicationId;
  
  /**
   * Constructor
   */
  public DHTApplication() {
  }
  
  /**
   * Sets a new application id.
   * @param name New application id.
   */
  public DHTApplication(String name) {
  	this.appId = name;
  }
  
  /**
   * An upcall to inform this Application for a new step.
   * This method is invoked at the end of each simulation step. 
   * Before this, may arrive any number of application Messages,
   * depending on your own main application.
   */
  public void byStep(){}
  
  /**
   * Makes a new instance of a Message to be sent with
   * the specified data.
   * @param data Data to be sent.
   * @return A new Message to be sent.
   */
  public Message makeTestMessage (String data) {
      return new DHTPeerTestMessage(this.endPoint.getId(),data);
  }

  /**
   * Sets the underlying EndPoint of this application.
   * @param ep Underlying EndPoint to be used in Message comunication.
   */
  public void setEndPoint(EndPoint ep) {
    endPoint = ep;
  }

  /**
   * This method is invoked on applications when the underlying node
   * is about to forward the given message with the provided target to
   * the specified next hop.  Applications can change the contents of
   * the message, specify a different nextHop (through re-routing), or
   * completely terminate the message.
   *
   * @param message The message being sent, containing an internal message
   * along with a destination key and nodeHandle next hop.
   *
   * @return Whether or not to forward the message further
   */
  public boolean forward(Message message) {
    System.out.println ("["+appId+"] over ["+endPoint.getId()+"]: Message forwarding...");
    return true;
  }

  /**
   * This method is called on the application at the destination node
   * for the given id.
   *
   * @param id The destination id of the message
   * @param message The message being sent
   */
  public void deliver (Id id, Message message) {
    if (message instanceof DHTPeerTestMessage) {
        DHTPeerTestMessage mesg = (DHTPeerTestMessage) message;
        System.out.println("["+this.endPoint.getId()+"] has received ["+ mesg.getData()+"] from ["+mesg.getSourceNodeId()+"]");
    }

  }
  
	/**
	 * Gets the identification of the Application
	 * @see planet.commonapi.Application#getId()
	 */
	public String getId() {
		return appId;
	}

	/**
	 * Sets the String identification of this application.
	 * @see planet.commonapi.Application#setId(java.lang.String)
	 * @param appId New identification of this application.
	 */
	public void setId(String appId) {
		this.appId = appId;
	}

	
	/**
	 * Owner DHTApplication method which permits to send a broadcast
	 * Message.
	 * @param textKey Text to be used as material for construct Message Id.
	 * @param mess Message to be send with broadcast.
	 */
	public void send(String textKey, DHTPeerTestMessage mess) {
		try {
			mess.setSourceNodeId(this.endPoint.getId());
			endPoint.broadcast(GenericFactory.buildKey(textKey), mess);
		} catch (InitializationException e) {
			e.printStackTrace();
            System.exit(-1);
		}
	}
	
	/**
	 * Shows a String representation of the actual Application.
	 * @see java.lang.Object#toString()
	 * @return String representation of this Application with its ApplicationId
	 * and its EndPoint reference.
	 */
	public String toString() {
		return "DHTApplication {id=["+this.appId+"] endPoint=["+this.endPoint+"]}";
	}
	
	/**
	 * Shows that the node has been <b>joinded</b> or not to the network.
	 * @see planet.commonapi.Application#update(planet.commonapi.NodeHandle, boolean)
	 * @param node Node that has been <b>joined</b> or leaved.
	 * @param joined If true, the <b>node</b> has been joinded. If false, the
	 * <b>node</b> has been leaved to the network.
	 */
	public void update(NodeHandle node, boolean joined) {
	}
    
    /**
     * Sets the name for this applicaton.
     * @param applicationName Name for this application.
     * @return The same instance, once it has been updated.
     */
    public Application setValues(String applicationName)
    {
        this.appId = applicationName;
        return this;
    }
}