IP查询系统的异步回调案例

 package com.lxj.demo;

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.MalformedURLException;
 import java.net.URL;

 public class Http extends Thread{
     // 下载结束的回调接口
     public interface IResult{
         void success(String msg);
         void fail(String msg);
     }
     // 创建网络地址的引用
     String addr;
     // 创建回调接口的引用
     IResult iResult ;
     // 生成构造方法把网络和接口的引用传进去
     public Http(String addr, IResult iResult) {
         super();
         this.addr = addr;
         this.iResult = iResult;
         // 开启线程  线程一开启就产生了异步
         start();
     }
     @Override
     // 重写线程的run方法，只要是网络就要用到多线程
     public void run() {
         try {
             // 创建URL，把网络地址传进去
             URL url = new URL(addr);
             try {
                 // 利用字符缓冲读取流读取网络数据
                 BufferedReader br = new BufferedReader(new InputStreamReader(url.openStream()));
                 // 创建stringbuffer对象
                 StringBuffer sb = new StringBuffer();
                 // 创建一个临时储存字符串的变量
                 String temp;
                 // 当temp不为空是就一直读取数据
                 while ((temp = br.readLine()) != null) {
                     sb.append(temp);
                 }
                 // 数据读取成功后
                 // 把读取的所有数据传到回调接口，再由接口传出去
                 iResult.success(sb.toString());
             } catch (IOException e) {
                 e.printStackTrace();
             }
         } catch (MalformedURLException e) {
             e.printStackTrace();
             // 网络请求发生异常
             iResult.fail("网络请求失败");
         }
     }
 }

package com.lxj.demo;

import net.sf.json.JSONObject;

import com.xykj.demo.Http.IResult;

public class IPRequest {
    // 请求IP信息的回调接口，在这里必须要使用回调，因为不知道Http什么时候下载完成
    public interface IRequest{
        void success(IPBean ipBean);
        void fail(String msg);
    }
    // 只要给一个ip地址和回调接口，我们可以通过回调接口传回转化好的ip信息对象
    public void request(String IP,IRequest iRequest){
        // 把用户输入的ip地址拼接到url中，发起Http请求
        String addr ="http://apicloud.mob.com/ip/query?key=520520test&ip="
                + IP
                + "";
        new Http(addr, new IResult() {
            // 创建完的IResult success和fail不会马上调用，必须要等到Http下载完成或者发生异常才会调用
            @Override
            public void success(String msg) {
                // 把接收的json数据转化成IPBean对象
                JSONObject jsonObject = JSONObject.fromObject(msg);
                IPBean ipBean = (IPBean) JSONObject.toBean(jsonObject, IPBean.class);
                // 产生回调，把转化好的对象传递出去给Demo
                iRequest.success(ipBean);
            }

            @Override
            public void fail(String msg) {
                // Http请求失败的时候
                iRequest.fail(msg);
            }
        });
    }
}

package com.lxj.demo;

public class IPBean {
    public static class Result{
        private String city;
        private String country;
        private String ip;
        private String province;
        public String getCity() {
            return city;
        }
        public void setCity(String city) {
            this.city = city;
        }
        public String getCountry() {
            return country;
        }
        public void setCountry(String country) {
            this.country = country;
        }
        public String getIp() {
            return ip;
        }
        public void setIp(String ip) {
            this.ip = ip;
        }
        public String getProvince() {
            return province;
        }
        public void setProvince(String province) {
            this.province = province;
        }
        @Override
        // 这里必须要重写toString方法，否则将打印的内存里面的地址
        public String toString() {
            return "city：" + city + "\ncountry：" + country + "\nip："
                    + ip + "\nprovince：" + province;
        }

    }
    Result result;
    private String msg;
    private String retCode;
    public Result getResult() {
        return result;
    }
    public void setResult(Result result) {
        this.result = result;
    }
    public String getMsg() {
        return msg;
    }
    public void setMsg(String msg) {
        this.msg = msg;
    }
    public String getRetCode() {
        return retCode;
    }
    public void setRetCode(String retCode) {
        this.retCode = retCode;
    }

}

package com.lxj.demo;

import java.util.Scanner;

import com.xykj.demo.IPRequest.IRequest;

public class Demo {
    public static void main(String[] args) {
        System.out.println("************欢迎使用IP查询系统************");
        Scanner sc = new Scanner(System.in);
        // 创建IPRequest对象
        IPRequest ipRequest = new IPRequest();
        while (true) {
            System.out.println("请输入要查询的IP:");
            String ip = sc.next();
            // 调用IPRequest里面的request方法
            ipRequest.request(ip, new IRequest() {
                @Override
                public void success(IPBean ipBean) {
                    System.out.println("*************查询结果*************");
                    System.out.println(ipBean.getResult());
                }
                @Override
                public void fail(String msg) {
                    System.out.println(msg);
                }
            });

        }
    }
}