菜鸟硕枫设计模式系列之14 职责链模式

职责链模式是保证一个事件一定能够被处理的一种模式。比如：一个coder去请假，temLeader批5天一下的，Manager批10天的，就这么简单。职责链模式是一种行为模式。

职责链模式类图：
[img]http://dl.iteye.com/upload/attachment/364668/53040d7b-7b4a-3089-8bd4-83a72de64730.jpg[/img]

说明：
Coder发出Something请求，经过TeamLeader->Manager构成的链，如果TeamLeader能处理，就返回结果，不能则有Manager处理。变化之处在于，当TeamLeader不在时（也可以是因为某种原因这里down掉了），则由链中其他环节去处理了，这样就保证了请求一定能被处理，增强了系统的健壮性。


具体代码：

package chainOfResponsibilityPattern;

public class Something {
	private String name;
	private int days;

	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getDays() {
		return days;
	}
	public void setDays(int days) {
		this.days = days;
	}

}

抽象人

package chainOfResponsibilityPattern;

public abstract class Person {

	private Something something;
	private boolean isHere;//上班标志位

	public abstract void request(Something something,Person toperson);
	public abstract void response(Person person);

	public Something getSomething() {
		return something;
	}
	public void setSomething(Something something) {
		this.something = something;
	}
	public boolean isHere() {
		return isHere;
	}
	public void setHere(boolean isHere) {
		this.isHere = isHere;
	}

}

manager:

package chainOfResponsibilityPattern;

public class Manager extends Person{

	@Override
	public void request(Something something, Person toperson) {
		// TODO Auto-generated method stub

	}

	@Override
	public void response(Person person) {
		if(person.getSomething().getDays()<10&&this.isHere()){
			System.out.println("Manager deal with it");
			System.out.println("Agree");
		}else{
			System.out.println("Disagree");
		}
	}

}

码农：

package chainOfResponsibilityPattern;

public class Coder extends Person{

	private Something something;
	private Person leader;

	public Person getLeader() {
		return leader;
	}

	public void setLeader(Person leader) {
		this.leader = leader;
	}

	public Something getSomething() {
		return something;
	}

	public void setSomething(Something something) {
		this.something = something;
	}

	@Override
	public void response(Person person) {
		// TODO Auto-generated method stub

	}
	@Override
	public void request(Something something,Person toPerson) {

		System.out.println("For "+something.getName()+" ask for a " +
				"leave of about "+something.getDays()+" days");

		leader.response(Coder.this);
	}

}

TeamLeader

package chainOfResponsibilityPattern;

public class TeamLeader extends Person{

	private Person leader;
	private boolean isHere;

	public Person getLeader() {
		return leader;
	}

	public void setLeader(Person leader) {
		this.leader = leader;
	}


	@Override
	public void response( Person person) {
		if(person.getSomething().getDays()<5 && this.isHere){
			System.out.println("Agree");
		}else{
			System.out.println("TeamLeader can not deal,send it to Manager");
			leader.response(person);
		}

	}

	@Override
	public void request(Something something, Person toperson) {


	}


}

测试类：

package chainOfResponsibilityPattern;

public class ChainOfResponsibilityTest {

	public static void main(String[] args){
		Something something = new Something();
		something.setDays(4);
		something.setName("nothing");

		Coder coder = new Coder();
		coder.setSomething(something);


		TeamLeader teamLeader = new TeamLeader(); 
		Person manager = new Manager();

		manager.setHere(true);
		teamLeader.setHere(true);
		teamLeader.setLeader(manager);
		coder.setLeader(teamLeader);

		coder.request(something, teamLeader);

		teamLeader.setHere(false);
		manager.setHere(true);
		coder.setSomething(something);
		coder.request(something, teamLeader);


	}
}