《大话设计模式》java实现之责任链模式

最新推荐文章于 2025-06-04 20:47:53 发布

原创最新推荐文章于 2025-06-04 20:47:53 发布 · 565 阅读

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文章标签：

#设计模式 #责任链模式

本文通过一个具体的请假审批流程实例，详细介绍了责任链模式的应用。该模式允许请求沿着处理者链传递，直到找到能够处理它的对象。文章展示了如何通过设置上级处理者来构建链条，并提供了完整的代码实现。

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责任链模式各个对象的下一个处理对象在客户端指定，可以自由组合，灵活性强，状态模式各状态则是在编译时设置，即在各状态对象中指定，可对比struts的filter。
另外，书中变量的命名如jingli、zongjian、zongjingli这些是为了让读者区分，实际上不推荐使用拼音命名，我觉得还不如在name属性中设置成经理、总监、总经理比使用金利、宗剑这些要好
UML
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代码结构

public class Client {
    public static void main(String[] args) {
        CommonManager jinli = new CommonManager("金利");
        Majordomo zongjian = new Majordomo("宗剑");
        GeneralManager zongjingli = new GeneralManager("钟精励");
        jinli.setSuperior(zongjian);
        zongjian.setSuperior(zongjingli);

        Request request = new Request();
        request.setRequestType("请假");
        request.setRequestContent("小菜请假");
        request.setNumber(1);
        jinli.requestApplications(request);

        Request request2 = new Request();
        request2.setRequestType("请假");
        request2.setRequestContent("小菜请假");
        request2.setNumber(4);
        jinli.requestApplications(request2);

        Request request3 = new Request();
        request3.setRequestType("加薪");
        request3.setRequestContent("小菜请求加薪");
        request3.setNumber(500);
        jinli.requestApplications(request3);

        Request request4 = new Request();
        request4.setRequestType("加薪");
        request4.setRequestContent("小菜请求加薪");
        request4.setNumber(1000);
        jinli.requestApplications(request4);
    }
}

public class CommonManager extends Manager {

    public CommonManager(String name) {
        super(name);
    }

    @Override
    public void requestApplications(Request request) {
        if("请假".equals(request.getRequestType()) && request.getNumber() <= 2) {
            System.out.println(name + ":" + request.getRequestContent() + "数量" + 
                    request.getNumber() + "被批准");
        } else {
            if(getSuperior() != null) {
                getSuperior().requestApplications(request);
            }
        }
    }

}

//总经理
public class GeneralManager extends Manager {

    public GeneralManager(String name) {
        super(name);
    }

    @Override
    public void requestApplications(Request request) {
        if("请假".equals(request.getRequestType())) {
            System.out.println(name + ":" + request.getRequestContent() + "数量" + 
                    request.getNumber() + "被批准");
        } else if("加薪".equalsIgnoreCase(request.getRequestType()) && request.getNumber() <= 500){
            System.out.println(name + ":" + request.getRequestContent() + "数量" + 
                    request.getNumber() + "被批准");
        } else if("加薪".equalsIgnoreCase(request.getRequestType()) && request.getNumber() > 500){
            System.out.println(name + ":" + request.getRequestContent() + "数量" + 
                    request.getNumber() + "再说吧");
        }
    }

}

//总监
public class Majordomo extends Manager {

    public Majordomo(String name) {
        super(name);
    }

    @Override
    public void requestApplications(Request request) {
        if("请假".equals(request.getRequestType()) && request.getNumber() <= 5
                ) {
            System.out.println(name + ":" + request.getRequestContent() + "数量" + 
                    request.getNumber() + "被批准");
        } else {
            if(getSuperior() != null) {
                getSuperior().requestApplications(request);
            }
        }
    }

}

public abstract class Manager {
    protected String name;

    public Manager(String name) {
        super();
        this.name = name;
    }

    private Manager superior;

    public Manager getSuperior() {
        return superior;
    }

    public void setSuperior(Manager superior) {  //关键的方法
        this.superior = superior;
    }

    public abstract void requestApplications(Request request);
}

public class Request {
    //申请类别
    private String requestType;
    //申请内容
    private String requestContent;
    //数量
    private int number;

    public String getRequestType() {
        return requestType;
    }
    public void setRequestType(String requestType) {
        this.requestType = requestType;
    }
    public String getRequestContent() {
        return requestContent;
    }
    public void setRequestContent(String requestContent) {
        this.requestContent = requestContent;
    }
    public int getNumber() {
        return number;
    }
    public void setNumber(int number) {
        this.number = number;
    }

}

运行结果
这里写图片描述