Android中實現JSON字串和JSON物件的轉換

json字串到json物件萬能轉換器（java實現），就一百來行程式碼，非常輕量小巧。對於一般應用場景資源消耗非常低，速度也足夠快，尤其適用於Android應用開發。

通過CommonJSONParser可以把json字串轉換為包含Map、List、String、Integer等標準Java物件的集合，具體使用方法：

CommonJSONParser commonJSONParser = new CommonJSONParser();
Map<String, Object> result = commonJSONParser.parse(jsonDataStr);

CommonJSONParser原始碼如下（主要使用“遞迴”思想）：

1 import java.util.ArrayList; 
 2 import java.util.HashMap; 
 3 import java.util.Iterator; 
 4 import java.util.List; 
 5 import java.util.Map; 
 6  
 7 import org.json.JSONArray; 
 8 import org.json.JSONException; 
 9 import org.json.JSONObject; 
10  
11 public class CommonJSONParser { 
12  
13     public Map<String, Object> parse(String jsonStr) { 
14  
15         Map<String, Object> result = null; 
16  
17         if (null != jsonStr) { 
18             try { 
19  
20                 JSONObject jsonObject = new JSONObject(jsonStr); 
21                 result = parseJSONObject(jsonObject); 
22  
23             } catch (JSONException e) { 
24                 // TODO Auto-generated catch block 
25                 e.printStackTrace(); 
26             } 
27         } // if (null != jsonStr) 
28  
29         return result; 
30     } 
31  
32     private Object parseValue(Object inputObject) throws JSONException { 
33         Object outputObject = null; 
34  
35         if (null != inputObject) { 
36  
37             if (inputObject instanceof JSONArray) { 
38                 outputObject = parseJSONArray((JSONArray) inputObject); 
39             } else if (inputObject instanceof JSONObject) { 
40                 outputObject = parseJSONObject((JSONObject) inputObject); 
41             } else if (inputObject instanceof String || inputObject instanceof Boolean || inputObject instanceof Integer) { 
42                 outputObject = inputObject; 
43             } 
44  
45         } 
46  
47         return outputObject; 
48     } 
49  
50     private List<Object> parseJSONArray(JSONArray jsonArray) throws JSONException { 
51  
52         List<Object> valueList = null; 
53  
54         if (null != jsonArray) { 
55             valueList = new ArrayList<Object>(); 
56  
57             for (int i = 0; i < jsonArray.length(); i++) { 
58                 Object itemObject = jsonArray.get(i); 
59                 if (null != itemObject) { 
60                     valueList.add(parseValue(itemObject)); 
61                 } 
62             } // for (int i = 0; i < jsonArray.length(); i++) 
63         } // if (null != valueStr) 
64  
65         return valueList; 
66     } 
67  
68     private Map<String, Object> parseJSONObject(JSONObject jsonObject) throws JSONException { 
69  
70         Map<String, Object> valueObject = null; 
71         if (null != jsonObject) { 
72             valueObject = new HashMap<String, Object>(); 
73  
74             Iterator<String> keyIter = jsonObject.keys(); 
75             while (keyIter.hasNext()) { 
76                 String keyStr = keyIter.next(); 
77                 Object itemObject = jsonObject.opt(keyStr); 
78                 if (null != itemObject) { 
79                     valueObject.put(keyStr, parseValue(itemObject)); 
80                 } // if (null != itemValueStr) 
81  
82             } // while (keyIter.hasNext()) 
83         } // if (null != valueStr) 
84  
85         return valueObject; 
86     } 
87 }