java对象和json对象之间互相转换

1. import java.util.ArrayList;  
2. import java.util.Collection;  
3. import java.util.Iterator;  
4. import java.util.List;  
5.   
6. import net.sf.json.JSONArray;  
7. import net.sf.json.JSONObject;  
8.   
9. public class MainClass {  
10.   
11.     public static void main(String[] args) {  
12.         TestJsonBean();  
13.         TestJsonAttribute();  
14.         TestJsonArray();          
15.     }  
16.   
17.     @SuppressWarnings("rawtypes")  
18.     private static void TestJsonArray() {  
19.         Student student1 = new Student();  
20.         student1.setId(1);  
21.         student1.setName("jag");  
22.         student1.setSex("man");  
23.         student1.setAge(25);  
24.         student1.setHobby(new String[]{"篮球","游戏"});  
25.           
26.         Student student2 = new Student();  
27.         student2.setId(2);  
28.         student2.setName("tom");  
29.         student2.setSex("woman");  
30.         student2.setAge(23);  
31.         student2.setHobby(new String[]{"上网","跑步"});  
32.           
33.         List<Student> list = new ArrayList<Student>();  
34.         list.add(student1);  
35.         list.add(student2);  
36.           
37.         JSONArray jsonArray = JSONArray.fromObject(list);  
38.         System.out.println(jsonArray.toString());  
39.           
40.         JSONArray new_jsonArray=JSONArray.fromObject(jsonArray.toArray());  
41.         Collection java_collection=JSONArray.toCollection(new_jsonArray);  
42.         if(java_collection!=null && !java_collection.isEmpty())  
43.         {  
44.             Iterator it=java_collection.iterator();  
45.             while(it.hasNext())  
46.             {  
47.                 JSONObject jsonObj=JSONObject.fromObject(it.next());  
48.                 Student stu=(Student) JSONObject.toBean(jsonObj,Student.class);  
49.                 System.out.println(stu.getName());  
50.             }  
51.         }  
52.     }  
53.   
54.     private static void TestJsonAttribute() {  
55.         /** 
56.          * 创建json对象并为该对象设置属性 
57.          */  
58.         JSONObject jsonObj = new JSONObject();  
59.         jsonObj.put("Int_att",25);//添加int型属性  
60.         jsonObj.put("String_att","str");//添加string型属性  
61.         jsonObj.put("Double_att",12.25);//添加double型属性  
62.         jsonObj.put("Boolean_att",true);//添加boolean型属性  
63.         //添加JSONObject型属性  
64.         JSONObject jsonObjSon = new JSONObject();  
65.         jsonObjSon.put("id", 1);  
66.         jsonObjSon.put("name", "tom");  
67.         jsonObj.put("JSONObject_att",jsonObjSon);  
68.         //添加JSONArray型属性  
69.         JSONArray jsonArray = new JSONArray();  
70.         jsonArray.add("array0");  
71.         jsonArray.add("array1");  
72.         jsonArray.add("array2");  
73.         jsonArray.add("array3");  
74.         jsonObj.put("JSONArray_att", jsonArray);  
75.         System.out.println(jsonObj.toString());  
76.         System.out.println("Int_att:"+jsonObj.getInt("Int_att"));  
77.         System.out.println("String_att:"+jsonObj.getString("String_att"));  
78.         System.out.println("Double_att:"+jsonObj.getDouble("Double_att"));  
79.         System.out.println("Boolean_att:"+jsonObj.getBoolean("Boolean_att"));  
80.         System.out.println("JSONObject_att:"+jsonObj.getJSONObject("JSONObject_att"));  
81.         System.out.println("JSONArray_att:"+jsonObj.getJSONArray("JSONArray_att"));  
82.     }  
83.   
84.     /** 
85.      * java对象与json对象互相转换 
86.      */  
87.     private static void TestJsonBean() {  
88.         /** 
89.          * 创建java对象 
90.          */  
91.         Student student = new Student();  
92.         student.setId(1);  
93.         student.setName("jag");  
94.         student.setSex("man");  
95.         student.setAge(25);  
96.         student.setHobby(new String[]{"篮球","上网","跑步","游戏"});  
97.         /** 
98.          * java对象转换成json对象，并获取json对象属性 
99.          */  
100.         JSONObject jsonStu = JSONObject.fromObject(student);  
101.         System.out.println(jsonStu.toString());  
102.         System.out.println(jsonStu.getJSONArray("hobby"));  
103.         /** 
104.          * json对象转换成java对象，并获取java对象属性 
105.          */  
106.         Student stu = (Student) JSONObject.toBean(jsonStu, Student.class);  
107.         System.out.println(stu.getName());  
108.         /** 
109.          * 创建json对象 
110.          */  
111.         JSONObject jsonObj = new JSONObject();  
112.         jsonObj.put("id",1);  
113.         jsonObj.put("name","张勇");  
114.         jsonObj.put("sex","男");  
115.         jsonObj.put("age",24);  
116.         //jsonObj.put("hobby",new String[]{"上网","游戏","跑步","音乐"});  
117.         //System.out.println(jsonObj.toString());  
118.         /** 
119.          * json对象转换成java对象 
120.          */  
121.         Student stud = (Student) JSONObject.toBean(jsonObj,Student.class);  
122.         System.out.println(stud.getName());       
123.     }  
124. }  

java对象和json对象之间互相转换

原文：http://www.cnblogs.com/zhwl/p/4766814.html