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javase请求并解析后端返回的json数据

发布时间：2017-09-21 17:31:23编辑：雪饮阅读（）

 所需附件：

fastjson-1.2.38.jar

f23a1811ac9d25f3e75367983668bffe.jar (513.94 KB)

后端返回json数据如：

{"msg":1,"data":[{"id":1,"title":"test1"},{"id":2,"title":"test2"}]}

 

在eclipse项目目录中建立lib文件夹将下载的jar文件fastjson-1.2.38.jar放进该文件夹中。然后执行如下操作：



建立jsonbean包并在该包下建立空的bean模型：

package bean;

 

import java.util.List;

 

 

public class JsonBean {

 

    private int msg;

    private List<JsonBean.DataBean> listBean;

   

    public int getMsg() {

       return msg;

    }

 

    public void setMsg(int msg) {

       this.msg = msg;

    }

 

    public List<JsonBean.DataBean> getListBean() {

       return listBean;

    }

 

    public void setListBean(List<JsonBean.DataBean> listBean) {

       this.listBean = listBean;

    }

 

 

 

    public static class DataBean{

       private int id;

       private String title;

       public int getId() {

           return id;

       }

       public void setId(int id) {

           this.id = id;

       }

       public String getTitle() {

           return title;

       }

       public void setTitle(String title) {

           this.title = title;

       }

    }

 

 

    @Override

    public String toString() {

       return "JsonBean [msg=" + msg + ", listBean=" + listBean

              + ", getMsg()=" + getMsg() + ", getListBean()=" + getListBean()

              + ", getClass()=" + getClass() + ", hashCode()=" + hashCode()

              + ", toString()=" + super.toString() + "]";

    }

   

   

}

建立net.sf.json包并建立JSONObject类（用来解析json并填充bean）：

package net.sf.json;

 

import java.util.ArrayList;

import java.util.List;

 

import com.alibaba.fastjson.JSONArray;

 

import bean.JsonBean;

import bean.JsonBean.DataBean;

 

public class JSONObject {

    public static JsonBean fromObjects(String str){

       com.alibaba.fastjson.JSONObject object = com.alibaba.fastjson.JSONObject.parseObject(str);

       JsonBean bean = new  JsonBean();

       bean.setMsg(object.getIntValue("msg"));

       JSONArray array = object.getJSONArray("data");

       List<JsonBean.DataBean> list = new ArrayList<JsonBean.DataBean>();

       for(int i = 0; i < array.size(); i ++){

           JsonBean.DataBean bean2 = new DataBean();

           com.alibaba.fastjson.JSONObject object2 = com.alibaba.fastjson.JSONObject.parseObject(array.get(i).toString());

           bean2.setId(object2.getIntValue("id"));

           bean2.setTitle(object2.getString("title"));

           list.add(bean2);

       }

       bean.setListBean(list);

       return bean;

    }

 

}

 

建立ui包，并在包里建立HttpRequestUtil用来获取网络接口：

package ui;

 

import java.io.BufferedReader; 

import java.io.IOException; 

import java.io.InputStream; 

import java.io.InputStreamReader; 

import java.io.OutputStream; 

import java.net.ConnectException; 

import java.net.HttpURLConnection; 

import java.net.URL; 

 

import bean.JsonBean;

 

import net.sf.json.JSONObject; 

/**

 * 发起http请求并获取结果 

 * @author zyz

 * @date 20140522

 *

 */ 

public class HttpRequestUtil { 

    /** 

     * 发起http请求并获取结果 

     *  

     * @param requestUrl 请求地址 

     * @param requestMethod 请求方式（GET、POST） 

     * @param outputStr 提交的数据 

     * @return JSONObject(通过JSONObject.get(key)的方式获取json对象的属性值) 

     */   

    public static JsonBean httpRequest(String requestUrl, String requestMethod, String outputStr) {     

        JsonBean jsonBean = null;

        StringBuffer buffer = new StringBuffer(); 

        InputStream inputStream=null; 

        try { 

            URL url = new URL(requestUrl); 

            HttpURLConnection httpUrlConn = (HttpURLConnection) url.openConnection();   

            httpUrlConn.setDoOutput(true);   

            httpUrlConn.setDoInput(true);   

            httpUrlConn.setUseCaches(false); 

            // 设置请求方式（GET/POST）   

            httpUrlConn.setRequestMethod(requestMethod);   

            if ("GET".equalsIgnoreCase(requestMethod))   

                httpUrlConn.connect();   

   

            // 当有数据需要提交时   

            if (null != outputStr) {   

                OutputStream outputStream = httpUrlConn.getOutputStream();   

                // 注意编码格式，防止中文乱码   

                outputStream.write(outputStr.getBytes("UTF-8"));   

                outputStream.close();   

            } 

            //将返回的输入流转换成字符串   

            inputStream = httpUrlConn.getInputStream();   

            InputStreamReader inputStreamReader = new InputStreamReader(inputStream, "utf-8");   

            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);   

   

            String str = null;   

            while ((str = bufferedReader.readLine()) != null) {   

                buffer.append(str);   

            }   

            bufferedReader.close();   

            inputStreamReader.close();   

            // 释放资源   

            inputStream.close();   

            inputStream = null;   

            httpUrlConn.disconnect();   

            jsonBean = JSONObject.fromObjects(buffer.toString()); 

        } catch (ConnectException ce) {   

              ce.printStackTrace(); 

              System.out.println("连接超时"); 

        } catch (Exception e) {   

               e.printStackTrace(); 

               System.out.println("http request error:{}"); 

        }finally{ 

            try { 

                if(inputStream!=null){ 

                    inputStream.close(); 

                } 

            } catch (IOException e) {

                e.printStackTrace(); 

            } 

        }  

        return jsonBean;   

    }   

 

} 

ui包下建立test类做测试：

package ui;

 

import bean.JsonBean;

import net.sf.json.JSONObject;

 

public class test {

 

    /**

     * @param args

     */

    public static void main(String[] args) {

       JsonBean jsonData=HttpRequestUtil.httpRequest("http://localhost/", "POST", "");

      

       //访问数组

       for(int i=0;i<jsonData.getListBean().size();i++){

           System.out.print(jsonData.getListBean().get(i).getTitle()+"\n");

       }

       //直接访问属性

       System.out.println(jsonData.getMsg());

    }

 

 

}