谷歌的Gson.jar:

//list转换为json
Gson gson = new Gson();  
List<Person> persons = new ArrayList<Person>();  
String str = gson.toJson(persons);  

//json转换为list
Gson gson = new Gson();  
List<Person> persons = gson.fromJson(str, new TypeToken<List<Person>>(){}.getType());  

阿里的fastJson.jar：

//list转换为json
List<CustPhone> list = new ArrayList<CustPhone>();
String str=JSON.toJSON(list).toString();

//json转换为list
  List<Person> list = new ArrayList<Person>();  
        list = JSONObject.parseArray(jasonArray, Person.class); 

JSON和list之间的转换