《HeadFirst设计模式(第二版)》第十一章代码——代理模式

代码文件目录：

RMI：

MyRemote

package Chapter11_ProxyPattern.RMI;

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface MyRemote extends Remote {
    public String sayHello() throws RemoteException;
}

MyRemoteClient

package Chapter11_ProxyPattern.RMI;

import java.rmi.Naming;

public class MyRemoteClient {
    public static void main(String[] args) {
        new MyRemoteClient().go();
    }

    public void go(){
        try{
            MyRemote service = (MyRemote) Naming.lookup("rmi://127.0.0.1/RemoteHello");
            String s = service.sayHello();
            System.out.println(s);
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }
}

MyRemoteImpl

package Chapter11_ProxyPattern.RMI;

import java.rmi.Naming;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class MyRemoteImpl extends UnicastRemoteObject implements MyRemote {
    private static final long serialVersion = 1L;

    public String sayHello() throws RemoteException {
        return "Server says: Hey!";
    }

    public MyRemoteImpl()throws RemoteException{}

    public static void main(String[] args) {
        try{
            MyRemote service = new MyRemoteImpl();
            Naming.rebind("RemoteHello",service);
        }catch (Exception ex){
            ex.printStackTrace();
        }
    }
}

能够远程监控的糖果机：

在上一章的代码的基础上做一些修改

GumballMachine

public class GumballMachine
        extends UnicastRemoteObject implements GumballMachineRemote
    {
    private static final long serialVersionUID = 2L;
    //加上地理位置支持
    String location;
    State soldOutState;
    State noQuarterState;
    State hasQuarterState;
    State soldState;
    State winnerState;

    State state = soldOutState;
    int count = 0;

    public GumballMachine(String location,int numberGumballs) throws RemoteException {
        soldOutState = new SoldOutState(this);
        noQuarterState = new NoQuarterState(this);
        hasQuarterState = new HasQuarterState(this);
        soldState = new SoldState(this);
        winnerState = new WinnerState(this);

        this.location = location;
        this.count = numberGumballs;
        if (numberGumballs > 0) {
            state = noQuarterState;
        }
    }

GumballMachineRemote

package Chapter11_ProxyPattern.Origin;

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface GumballMachineRemote extends Remote {
    public int getCount() throws RemoteException;
    public String getLocation() throws RemoteException;
    public State getState() throws RemoteException;
}

GumballMachineTestDrive

package Chapter11_ProxyPattern.Origin;

import java.rmi.Naming;

/**
 * @Author 竹心
 * @Date 2023/8/19
 **/

public class GumballMachineTestDrive {
    public static void main(String[] args) {
        GumballMachineRemote gumballMachine = null;
        int count;

        if (args.length < 2) {
            System.out.println("GumballMachine <name> <inventory>");
            System.exit(1);
        }

        try {
            count = Integer.parseInt(args[1]);

            gumballMachine =
                    new GumballMachine(args[0], count);
            Naming.rebind("//" + args[0] + "/gumballmachine", gumballMachine);
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

GumballMonitor

package Chapter11_ProxyPattern.Origin;

import java.rmi.RemoteException;

/**
 * @Author 竹心
 * @Date 2023/8/20
 **/

//糖果监视器
public class GumballMonitor {
    GumballMachineRemote gumballMachine;

    public GumballMonitor(GumballMachineRemote machine){
        this.gumballMachine = machine;
    }

    public void report(){
        try{
            System.out.println("Gumball Machine: "+this.gumballMachine.getLocation());
            System.out.println("Current inventory: "+this.gumballMachine.getCount()+" gumballs");
            System.out.println("Current State: "+this.gumballMachine.getState());
        }catch (RemoteException e){
            e.printStackTrace();
        }

    }
}

GumballMonitorTestDrive

package Chapter11_ProxyPattern.Origin;

import java.rmi.Naming;

public class GumballMonitorTestDrive {
    public static void main(String[] args) {
        String[] location = {"rmi://127.0.0.1/gumballmachine",
                "rmi://127.0.0.1/gumballmachine",
                "rmi://127.0.0.1/gumballmachine"};

        if (args.length >= 0)
        {
            location = new String[1];
            location[0] = "rmi://" + args[0] + "/gumballmachine";
        }

        GumballMonitor[] monitor = new GumballMonitor[location.length];


        for (int i=0;i < location.length; i++) {
            try {
                GumballMachineRemote machine =
                        (GumballMachineRemote) Naming.lookup(location[i]);
                monitor[i] = new GumballMonitor(machine);
                System.out.println(monitor[i]);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        for (int i=0; i < monitor.length; i++) {
            monitor[i].report();
        }
    }
}

五个状态类：

同样的修改：

public class HasQuarterState implements State {
    private static final long serialVersionUID = 2L;
    Random randomWinner = new Random(System.currentTimeMillis());