1.從Object到String
要先用Object對象構造一個JSONObject或者JSONArray對象，然后調用它的toString()方法即可
（1）示例一
1 Book book=new Book();
2 book.setName("Java");
3 book.setPrice(52.3f);
4 JSONObject object=JSONObject.fromObject(book);
5 System.out.println(object.toString());
（2）示例二
1 Book book=new Book();
2 book.setName("Java");
3 book.setPrice(52.3f);
4
5 Book book2=new Book();
6 book2.setName("C");
7 book2.setPrice(42.3f);
8 List list=new ArrayList();
9 list.add(book);
10 list.add(book2);
11 JSONArray arry=JSONArray.fromObject(list);
12 System.out.println(arry.toString());
13 //結果如下：
14 [{"name":"Java","price":52.3},{"name":"C","price":42.3}]
2.從String到Object
要先用String對象構造一個JSONObject或者JSONArray對象
(1)示例一
1 String json="{name:'Java',price:52.3}";
2 JSONObject object=JSONObject.fromObject(json);
3 System.out.println(object.get("name")+" "+object.get("price"));(2)示例二
1 String json="[{name:'Java',price:52.3},{name:'C',price:42.3}]";
2 JSONArray array=JSONArray.fromObject(json);
3 for(int i=0;i<array.size();i++){
4 Map o=(Map)array.get(i);
5 System.out.println(o.get("name")+" "+o.get("price"));
6 } 3.從String到Bean
(1)單個Bean對象
1 String json="{name:'Java',price:52.3}";
2 JSONObject object=JSONObject.fromObject(json);
3 Product product=(Product)JSONObject.toBean(object,Product.class);
4 System.out.println(product.getName()+" "+product.getPrice());(2).Bean的數組
1 String json="[{name:'Java',price:52.3},{name:'C',price:42.3}]";
2 JSONArray array=JSONArray.fromObject(json);
3 Product[] products=(Product[]) JSONArray.toArray(array,Product.class);
4 for(Product p:products){
5 System.out.println(p.getName()+" "+p.getPrice());
6 } 自定義封裝JSON操作的類
1 package com.util;
2
3 import java.util.List;
4 import java.util.Map;
5
6 import net.sf.json.JSONArray;
7 import net.sf.json.JSONObject;
8
9 public class JsonHelper {
10 //從普通的Bean轉換為字符串
11 public static String getJson(Object o){
12 JSONObject jo=JSONObject.fromObject(o);
13 return jo.toString();
14 }
15 //從Java的列表轉換為字符串
16 public static String getJson(List list){
17 JSONArray ja=JSONArray.fromObject(list);
18 return ja.toString();
19 }
20 //從Java對象數組轉換為字符串
21 public static String getJson(Object[] arry){
22 JSONArray ja=JSONArray.fromObject(arry);
23 return ja.toString();
24 }
25 //從json格式的字符串轉換為Map對象
26 public static Map getObject(String s){
27 return JSONObject.fromObject(s);
28 }
29 //從json格式的字符串轉換為List數組
30 public static List getArray(String s){
31 return JSONArray.fromObject(s);
32 }
33 //從json格式的字符串轉換為某個Bean
34 public static Object getObject(String s,Class cls){
35 JSONObject jo=JSONObject.fromObject(s);
36 return JSONObject.toBean(jo, cls);
37 }
38 //從json格式的字符串轉換為某類對象的數組
39 public static Object getArray(String s,Class cls){
40 JSONArray ja=JSONArray.fromObject(s);
41 return JSONArray.toArray(ja, cls);
42 }
43 }