把json格式的字符串存入到对象中

 package com.json.parse;

 import net.sf.json.JSONObject;

 import com.bean.Message;

 public class JsonParseDemo {
     public static void main(String[] args) {
         String jsonString = "{\"from\":\"老周\",\"to\":\"小周\",\"content\":\"hello\",\"type\":1}";

         Message msg = new Message();

         JSONObject jsonObject = JSONObject.fromObject(jsonString);

         msg.setFrom(jsonObject.getString("from"));
         msg.setContent(jsonObject.getString("content"));
         msg.setTo(jsonObject.getString("to"));
         msg.setType(jsonObject.getInt("type"));

         System.out.println(msg.toString());

     }
 }

Message.Java

 package com.bean;

 public class Message {
     private String from;
     private String to;
     private String content;
     private int type;

     public String getFrom() {
         return from;
     }

     public void setFrom(String from) {
         this.from = from;
     }

     public String getTo() {
         return to;
     }

     public void setTo(String to) {
         this.to = to;
     }

     public String getContent() {
         return content;
     }

     public void setContent(String content) {
         this.content = content;
     }

     public int getType() {
         return type;
     }

     public void setType(int type) {
         this.type = type;
     }

     public Message(String from, String to, String content, int type) {
         super();
         this.from = from;
         this.to = to;
         this.content = content;
         this.type = type;
     }

     public Message() {
         super();
     }

     public String toString() {
         return "Message [from=" + from + ", to=" + to + ", content=" + content
                 + ", type=" + type + "]";
     }

 }

json解析所需jar包

http://download.csdn.NET/detail/hoho_12/9600557

将json格式的数据存入对象中

MessageList.json

 [
 {
 "from":"小王",
 "to":"周",
 "content":"好好工作！",
 "type":1
 },
 {
 "from":"周",
 "to":"小王",
 "content":"我会加油的，争取早日回到中南海",
 "type":2
 }
 ]

 package com.json.parse;

 import java.io.*;
 import java.util.*;

 import net.sf.json.JSONArray;
 import net.sf.json.JSONObject;

 import com.bean.Message;
 public class MessageParse {
     public static void main(String[] args) throws IOException {
         String jsonString=readJson(new File("src/MessageList.json"));
         //System.out.println(jsonString);
         List messageList=parseJson(jsonString);
         System.out.println(messageList.toString());

     }

     private static List parseJson(String jsonString) {
         List messageList = new ArrayList();

         // 将jsonString 封装成jsonArray
         JSONArray jsonArray = JSONArray.fromObject(jsonString);
         // jsonArray数组放的是jsonObject
         for (int index = 0; index < jsonArray.size(); index++) {
             JSONObject jsonObject = jsonArray.getJSONObject(index);

             Message msg = new Message();
             msg.setFrom(jsonObject.getString("from"));
             msg.setTo(jsonObject.getString("to"));
             msg.setContent(jsonObject.getString("content"));
             msg.setType(jsonObject.getInt("type"));

             messageList.add(msg);
         }

         return messageList;
     }

     private static String readJson(File file) throws IOException {
         StringBuffer sb = new StringBuffer();
         BufferedReader br = new BufferedReader(new FileReader(file));
         String line = null;
         while ((line = br.readLine()) != null) {
             sb.append(line);
         }
         br.close();
         return sb.toString();
     }
 }