十五、状态模式

package com.shi.common;

public class StatePattern {

    public static void main(String[] args) {
        Server1 server1 = new Server1();
        String result = server1.getServer(2);
        System.out.println(result);
        result = server1.getServer(1);
        System.out.println(result);
        result = server1.getServer(3);
        System.out.println(result);
        result = server1.getServer(4);
        System.out.println(result);

    }

}

interface State{
    public String  getServer(int state);
}

class Server1 implements State{

    @Override
    public String getServer(int state) {
        if (state == 1) {
            return "服务器1，为您服务";
        }else{
            return new Server2().getServer(state);
        }
        
    }
    
}

class Server2 implements State{

    @Override
    public String getServer(int state) {
        if (state == 2) {
            return "服务器2，为您服务";
        }else{
            return new Server3().getServer(state);
        }
        
    }
    
}

class Server3 implements State{

    @Override
    public String getServer(int state) {
        if (state == 3) {
            return "服务器3，为您服务";
        }else{
            return "未找到服务器";
        }
        
    }
    
}

服务器2，为您服务
服务器1，为您服务
服务器3，为您服务
未找到服务器