java json，jsonarray各种变化解决方法

package wechat;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.List;

import java.util.Map;

import javax.json.JsonArray;

import net.sf.json.JSONArray;

import net.sf.json.JSONObject;

public class test2 {
public static void main(String[] args) {
MapToJson();
ListToJson();
ObjectToJson();
ObjectListToJson();
JsonToObject();
JsonListToObject();
}
/*
* Map转json
*/
public static void MapToJson(){
Map map=new HashMap();
map.put("name", "dajitui");
JSONObject jsonObject=JSONObject.fromObject(map);
System.out.println(jsonObject);
}
/*
* List转json
*/
public static void ListToJson(){
List list=new ArrayList();
Map map=new HashMap();
map.put("name", "dajitui");

list.add(map);
JSONArray jsonArray=JSONArray.fromObject(list);
System.out.println(jsonArray);
}
/*
* 对象转json
*/
public static JSONObject ObjectToJson(){
User user=new User(1, "dabai");
JSONObject jsonObject=JSONObject.fromObject(user);
//System.out.println(jsonObject);
return jsonObject;
}
/*
* 对象list转json
*/
public static JSONArray ObjectListToJson(){
User user=new User(1, "dabai");
User user1=new User(2, "dajitui");
List<User> list=new ArrayList<User>();
list.add(user);
list.add(user1);
JSONArray jsonArray=JSONArray.fromObject(list);
//System.out.println(jsonArray);
return jsonArray;
}
/*
* json转String
*/
public static void JsonToObject(){
JSONObject jsonObject=ObjectToJson();
int i=jsonObject.getInt("id");
String s=jsonObject.getString("name");
System.out.println(i+" "+s);
}
/*
* 复杂json转String
*/
public static void JsonListToObject(){
JSONArray jsonArray=ObjectListToJson();
for(int i=0;i<jsonArray.size();i++){
   JSONObject job = jsonArray.getJSONObject(i);  // 遍历 jsonarray 数组，把每一个对象转成 json 对象
   System.out.println(job.getInt("id")+" "+job.getString("name")) ;  // 得到 每个对象中的属性值
 }
}

} 

package wechat;

public class User{
private int id;
private String name;

public User(){}

public User(int id,String name){
this.id=id;
this.name=name;
}

public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}

}