http://www.verejava.com/?id=16992821172850

/**
    接口的实际应用:

    题目: 两个人A,B开发一个火车票显示功能A负责客户端, B负责服务器端

    思路:
        1. 抽象出类: 
            1.1 客户端显示类(Terminal)
            1.2 服务器端服务类(TrainService)
            1.3 火车票(Ticket)
        2. 找出类关系: 
            2.1 客户端 调用 服务器端 的获取火车票信息显示
                TrainService -> Terminal(调用)
            2.2 服务器端 提供 火车票信息 给 客户端 
                Ticket->TrainService(多对1) Ticket -> Terminal(多对多)
        3. 找出类属性:
            3.1 Ticket(车次,出发地,到达地,票价)
            3.2 TrainService(火车站名称)
            3.3 Terminal(代售点名称)
        4. 找出类方法: 
            4.1 TrainService: 提供火车票信息 Ticket[] getTickets()
            4.2 Terminal: 显示火车票信息 display()
*/
import java.util.Scanner;

public class ApplyInterface {
    
    public static void main(String[] args) {
        //北京西站火车票服务器打开
        TrainService beijingWestService = new BeijingWestTrainService("北京西站");
        //北京站火车票服务器打开
        TrainService beijingService = new BeijingTrainService("北京站");

        //我是北京朝阳区大黄庄的 代售点
        Terminal t = new Terminal("北京朝阳区大黄庄的 代售点");

        Scanner in = new Scanner(System.in);
        System.out.println("请输入要查的火车站代码 1:北京西站 2:北京站");
        int trainId = in.nextInt();

        if (trainId == 1) {
            t.setTrainService(beijingWestService);
        }
        if (trainId == 2) {
            t.setTrainService(beijingService);
        }

        //打开火车电脑终端 查看火车票信息
        t.display();
    }
}

class Ticket {
    
    private String id;//车次
    private String startCity;//出发城市
    private String endCity;//到达城市
    private float price;//票价

    public Ticket(String id, String startCity, String endCity, float price) {
        this.id = id;
        this.startCity = startCity;
        this.endCity = endCity;
        this.price = price;
    }

    public String getId() {
        return this.id;
    }

    public String getStartCity() {
        return this.startCity;
    }

    public String getEndCity() {
        return this.endCity;
    }

    public float getPrice() {
        return this.price;
    }
}

interface TrainService {
    //A和B约定一个提供火车票的方法
    public Ticket[] getTickets();

    //获取火车站名字
    public String getName();
}

class BeijingWestTrainService implements TrainService {
    
    private String name;

    public BeijingWestTrainService(String name) {
        this.name = name;
    }

    public String getName() {
        return this.name;
    }

    //提供火车票的实现方法
    public Ticket[] getTickets() {
        Ticket[] tickets = { new Ticket("T1", "北京", "长沙", 175f) };
        return tickets;
    }
}

class BeijingTrainService implements TrainService {
    
    private String name;

    public BeijingTrainService(String name) {
        this.name = name;
    }

    public String getName() {
        return this.name;
    }

    //提供火车票的实现方法
    public Ticket[] getTickets() {
        Ticket[] tickets = { new Ticket("T215", "北京", "吉林", 130f) };
        return tickets;
    }
}

class Terminal {
    
    private String proxy;//代售点名称
    private Ticket[] tickets;// 火车票引用
    private TrainService trainService;// 服务器接口引用

    public Terminal(String proxy) {
        this.proxy = proxy;
    }

    public void setTrainService(TrainService trainService) {
        this.trainService = trainService;
    }

    //显示火车票的信息
    //    思路:
    //        1. 首先要从服务器端 获取 火车票信息
    //        2. 循环把火车票信息显示在电脑终端上
    public void display() {
        //获取火车票信息
        tickets = trainService.getTickets();
        //输出火车票信息
        System.out.println(trainService.getName());
        System.out.println("车次------出发地------到达地------票价");
        if (tickets != null) {
            for (int i = 0; i < tickets.length; i++) {
                System.out.println(tickets[i].getId() + "------" + tickets[i].getStartCity() + "------" + tickets[i].getEndCity() + "------" + tickets[i].getPrice());
            }
        }
    }
}

http://www.verejava.com/?id=16992821172850