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);        }      });    }  }}