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

/**
 * This application only make two tasks: send a "Hello World" message and
 * receive it.
 * 
 * @author Carles Pairot <[e-mail]>
 * @author Jordi Pujol <[e-mail]>
 * @version 1.0
 */
public class DHTApplication implements Application {
	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() {
	}
	
	/**
	 * 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(){}
	
	/**
	 * Build a new DHTPeerTestMessage with the specified data.
	 * 
	 * @param data
	 *            Data to be sent with the new message.
	 * @return New generated Message with the data.
	 */
	public Message makeTestMessage(String data) {
		return new DHTPeerTestMessage(data);
	}
	/**
	 * Sets the underlying EndPoint for interact with the Node, for sending and
	 * receiving messages.
	 * 
	 * @param ep
	 *            EndPoint to interact.
	 */
	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
	 *            Application Message to test if is forwarding or not.
	 * 
	 * @return Whether or not to forward the message further. Always true.
	 */
	public boolean forward(Message message) {
		System.out.println("[" + appId + "] sobre [" + endPoint.getId()
				+ "]: Fent forward del missatge...");
		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("Delivered Message: "
					+ ((DHTPeerTestMessage) message).getData());
			System.out.println("Destination Node : " + this.endPoint.getId());
			System.out.println("Message Id       : " + id);
		}
	}
	/**
	 * Gets the identification of the Application
	 * 
	 * @see planet.commonapi.Application#getId()
	 */
	public String getId() {
		return appId;
	}
	/**
	 * Sets the identification of the Application
	 * 
	 * @see planet.commonapi.Application#setId(java.lang.String)
	 * @param appId
	 *            New String identification of this application.
	 */
	public void setId(String appId) {
		this.appId = appId;
	}
	/**
	 * This method permits to send a message with the specified key <b>textKey
	 * </b>
	 * 
	 * @param textKey
	 *            The String to use as key of the message.
	 * @param mess
	 *            Message to be sent.
	 */
	public void send(String textKey, DHTPeerTestMessage mess) {
		try {
			endPoint.route(GenericFactory.buildKey(textKey), mess, null);
		} catch (InitializationException e) {
			System.out.println("Cannot to be sent the message [" + mess
					+ "] with this key [" + textKey + "]");
			e.printStackTrace();
		}
	}
	
	/**
	 * 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;
    }

}