在前端：

1.如果json是List对象转换的，可以直接遍历json，读取数据。

2.如果是需要把前端的List对象转换为json传到后台，param是ajax的参数，那么转换如下所示：

var jsonStr = JSON.stringify(list); var param= {}; param.jsonStr=jsonStr;

在后台：

1.把String转换为List(str转换为list)

List<T> list = new ArrayList<T>(); JSONArray jsonArray = JSONArray.fromObject(str);//把String转换为json list = JSONArray.toList(jsonArray,t);//这里的t是Class<T>

2.把List转换为json

JSONArray json = JSONArray.fromObject(object); String str = json.toString();//把json转换为String

eg:

1.根据页面用户输入的信息形成 Answer 对象的List

/** * @param answers * @param question_ids * @param types * @return */ private List<Answer> toAnswerList(String[] studenAnswers, int[] question_ids, int[] types,int[] scores) { List<Answer> answerList = new ArrayList<Answer>(); if(studenAnswers!=null && question_ids!= null && types!= null&& scores!= null){ for (int i = 0; i < studenAnswers.length; i++) { Answer answer = new Answer(); String studenAnswer = studenAnswers[i]; int type = types[i]; int question_id = question_ids[i]; int score = scores[i]; answer.setQuestion_id(question_id); answer.setScore(score); answer.setStudenAnswer(studenAnswer); answer.setType(type); answerList.add(answer); } } return answerList; } /** * 将一个json字串转为list * @param props * @return */ public static List<Answer> converAnswerFormString(String answer){ if (answer == null || answer.equals("")) return new ArrayList(); JSONArray jsonArray = JSONArray.fromObject(answer); List<Answer> list = (List) JSONArray.toCollection(jsonArray, Answer.class); return list; }

2.将一个 Answer 对象的List 生成Json字串，是根据客户端页面用户输入的信息生成的

public String getAnswerString(String[] studenAnswers, int[] question_ids, int[] types,int[] scores) { List list = toAnswerList(studenAnswers, question_ids, types, scores); JSONArray jsonarray = JSONArray.fromObject(list); return jsonarray.toString(); }