behavioursinvokerimpl.java

来自「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」· Java 代码 · 共 84 行

package planet.generic.commonapi.behaviours;

import java.util.Random;

import planet.commonapi.Node;
import planet.commonapi.RouteMessage;
import planet.commonapi.behaviours.Behaviour;
import planet.commonapi.behaviours.BehavioursInvoker;

/**
 * This class is used to invoke a behaviour. It acts 
 * like a facade calling a behaviour only when several preconditions are met. 
 * Pre-conditions on this default implementation are probability-based.  
 * @author <a href="mailto: [e-mail]">Marc Sanchez</a>
 * @author <a href="mailto: [e-mail]">Jordi Pujol</a>
 */
public class BehavioursInvokerImpl implements BehavioursInvoker {
	/**
	 * Behaviour object: this properties is a placeholder for a behaviour.
	 */
	protected Behaviour beh = null;
	/**
	 * Behaviour property: probability to be checked.
	 */
	protected double prob;
	/**
	 * Randomizer.
	 */
	private java.util.Random random = null;

	/**
     * Builds an uninitialized BehavioursInvoker. Requires to invoke
     * setValues(...) method.
	 */
	public BehavioursInvokerImpl(){}
    
    /**
     * Initializes this invoker with specified values. 
     * @param behaviour Behaviour to be invoked at any incomming RouteMessage
     * @param probability The probability to be checked at any invokation
     * of specified Behaviour.
     * @return This same instance once has been initialized.
     */
    public BehavioursInvoker setValues(Behaviour behaviour, double probability) {
		this.beh = behaviour;
		this.prob = probability;
        this.random = new Random();
        return this;
	}
    
	/**
	 * This method invokes a behaviour. 
	 * @param msg The RouteMessage recently arrived.
	 * @param node The Node which holds the behaviour.
	 * @return Returns a BehaviourInvokerStatus with replies from the
	 * behaviour's invocation and a boolean signaling if the invocation
	 * was finally made.
	 */
	public boolean invoke(RouteMessage msg, Node node) {
		if (random.nextDouble() <= prob)
        {
            beh.onMessage(msg,node);
            return true;
        }
		else 
            return false;
	}
	/**
	 * @return Returns the name of a behaviour.
	 */
	public String getName() {
		return beh.getName();
	}
	/**
	 * @return Returns a string representation of the behaviour. In general, the toString
	 * method returns a string that "textually represents" this behaviour. The result should 
	 * be a concise but informative representation that is easy for a person to read. 
	 */ 
	public String toString() {
		return "Behaviour [" + this.beh + "] " +
			   "PreCondition On [" + this.prob + "]"; 
	}
}