责任链模式的目的是减轻调用者的压力，让它们无需了解哪个对象可以处理调用请求。
如果开发过程中遇到以下几种情况，可以考虑应用责任链模式：
有多个的对象可以处理一个请求，哪个对象处理该请求运行时刻自动确定
你想在不明确指定接收者的情况下，向多个对象中的一个提交一个请求
可处理一个请求的对象集合应被动态指定
public interface RequestHandle {
void handleRequest(Request request);
}public class HRRequestHandle implements RequestHandle {
public void handleRequest(Request request) {
if (request instanceof DimissionRequest) {
System.out.println("要离职, 人事审批!");
}
System.out.println("请求完毕");
}
}public class PMRequestHandle implements RequestHandle {
RequestHandle rh;
public PMRequestHandle(RequestHandle rh) {
this.rh = rh;
}
public void handleRequest(Request request) {
if (request instanceof AddMoneyRequest) {
System.out.println("要加薪, 项目经理审批!");
} else {
rh.handleRequest(request);
}
}
}public class TLRequestHandle implements RequestHandle {
RequestHandle rh;
public TLRequestHandle(RequestHandle rh) {
this.rh = rh;
}
public void handleRequest(Request request) {
if (request instanceof LeaveRequest) {
System.out.println("要请假, 项目组长审批!");
} else {
rh.handleRequest(request);
}
}
}public class Test {
public static void main(String[] args) {
RequestHandle hr = new HRRequestHandle();
RequestHandle pm = new PMRequestHandle(hr);
RequestHandle tl = new TLRequestHandle(pm);
//team leader处理离职请求
Request request = new DimissionRequest();
tl.handleRequest(request);
System.out.println("===========");
//team leader处理加薪请求
request = new AddMoneyRequest();
tl.handleRequest(request);
System.out.println("========");
//项目经理上理辞职请求
request = new DimissionRequest();
pm.handleRequest(request);
}
} Java设计模式——Chain of Responsibility（责任链）模式
原文：http://blog.csdn.net/lindonglian/article/details/46514667