http://blog.csdn.net/superit401/article/details/51727739

1.String转JSONObject

String jsonMessage = "{\"语文\":\"88\",\"数学\":\"78\",\"计算机\":\"99\"}";

JSONObject  myJson = JSONObject.fromObject(jsonMessage);

2.String转JSONArray

String jsonMessage = "[{'num':'成绩', '外语':88, '历史':65, '地理':99, 'object':{'aaa':'1111','bbb':'2222','cccc':'3333'}}," +
          "{'num':'兴趣', '外语':28, '历史':45, '地理':19, 'object':{'aaa':'11a11','bbb':'2222','cccc':'3333'}}," +
          "{'num':'爱好', '外语':48, '历史':62, '地理':39, 'object':{'aaa':'11c11','bbb':'2222','cccc':'3333'}}]";
 JSONArray myJsonArray = JSONArray.fromObject(jsonMessage);
 System.out.println(myJsonArray);

3.String转Map

(1)

String jsonMessage = "{\"语文\":\"88\",\"数学\":\"78\",\"计算机\":\"99\"}";

JSONObject  myJson = JSONObject.fromObject(jsonMessage);

Map m = myJson; 

(2) (需要引入jackjson的core、databind、annotations三个jar包  )

String json = "{\"PayPal key2\":\"PayPal value2\",\"PayPal key1\":\"PayPal value1\",\"PayPal key3\":\"PayPalvalue3\"}";  

ObjectMapper mapper = new ObjectMapper();    
 Map<String,Object> m = mapper.readValue(json, Map.class);  

(3)(特殊格式的String)

String a ="{se=2016, format=xml, at=en co=3}";

a =  a.substring(1, a.length()-1);
Map docType = new HashMap();  
Java.util.StringTokenizer items;  
for(StringTokenizer entrys = new StringTokenizer(a, ", ");entrys.hasMoreTokens();   
docType.put(items.nextToken(), items.hasMoreTokens() ? ((Object) (items.nextToken())) : null)){  
     items = new StringTokenizer(entrys.nextToken(), "=");  
   }

4.JSONObject、JSONArray,Map转String

JSONObject——String:

System.out.println(myJsonObject);//可直接输出JSONObject的内容

myJsonObject.toString();

JSONArray——String:

System.out.println(myJsonArray);//可直接输出myJsonArray的内容

myJsonArray.toString();

Map——String:

System.out.println(map);//可直接输出map的内容

map.toString();

5.JSONObject转JSONArray

6.JSONObject转Map

方法一:JSONObject  myJson = JSONObject.fromObject(jsonString);

Map m = myJson;

方法二:Map<String, Object> map = (Map<String, Object>) JSONObject.toBean(myJson, Map.class);

7.JSONArray转JSONObject

  for(int i=0 ; i < myJsonArray.length() ;i++)
   {
    //获取每一个JsonObject对象
    JSONObject myjObject = myJsonArray.getJSONObject(i);

}

8.JSONArray转Map

9.Map转JSONObject

JSONObject json = JSONObject.fromObject( map );  

10.Map转JSONArray

 JSONArray.fromObject(map);

11.List转JSONArray

JSONArray jsonArray2 = JSONArray.fromObject( list );     

12.JSONArray转List

List<Map<String,Object>> mapListJson = (List)jsonArray;

13.String转数组

String string = "a,b,c";
String [] stringArr= string.split(",");  //注意分隔符是需要转译滴...
如果是"abc"这种字符串,就直接
String string = "abc" ;
char [] stringArr = string.toCharArray(); //注意返回值是char数组
如果要返回byte数组就直接使用getBytes方法就ok了~~
String string = "abc" ;
byte [] stringArr = string.getBytes();

数组转String

char[] data={a,b,c}; 
String s=new String(data);