java中Json/List/Map/Object的相互转换

日常开发中免不了和json格式的字符串数组，list，json，map打交道，因此这篇文章的着重点就是这四者的相互转换

1、json格式的字符串数组转list

String json = "['北京','天津','杭州']";//"[\"北京\",\"天津\",\"杭州\"]";
 
    String[] pathArr = (json.substring(1, json.length() - 1)).split(",");//string数组
 
    // 使用Arrays.asList 转换
    List<String> pathList = Arrays.asList(pathArr);
    for (String s : pathList) {
        System.out.println(s);
    }
    //使用collections
    List list=new ArrayList();
    Collections.addAll(list,pathArr);
    for (Object o : list) {
        System.out.println(o);
    }

2、list转json格式数组

List<String> list1=new ArrayList<String>();
        list1.add("a");
        list1.add("b");
        list1.add("vc");
 
        JSONArray jsonArray = JSONArray.fromObject(list1);
        String string=jsonArray.toString();//string
        String[] sd = (string.substring(1, string.length() - 1)).split(",");//string数组
        System.out.println(sd instanceof String[]);
        for (String s : sd) {
            System.out.println(s);
        }

3、list转JSONArray

JSONArray jsonArray1=JSONArray.fromObject(list1);

4、JSONArray转list

List<String> list1=new ArrayList<String>();
        list1.add("a");
        list1.add("b");
        list1.add("vc");
        JSONArray jsonArray1=JSONArray.fromObject(list1);
        List<String> list=JSONArray.toList(jsonArray1);
        for (String s : list) {
            System.out.println(s);
        }

5、Java对象、list、map转json字符串

JSONObject.toJSONString(user);
JSONObject.toJSONString(list);
JSONObject.toJSONString(map);

6、json字符串转java对象、list、map

Employee employee=new Employee();
        employee.setA("a");
        employee.setB("bb");
        employee.setC("cc");
 
        String s= JSONObject.toJSONString(employee);//Java对象转json字符串
        System.out.println(s);
 
        employee=JSONObject.parseObject(s,Employee.class);//json字符串转java对象
        System.out.println(employee.toString());
        
 
        public static String jsonmap = "{\"001\":           {\"name\":\"xiaohong\",\"password\":\"654321\"},\"002\":[{\"$ref\":\"$.001\"},{\"name\":\"xixi\",\"password\":\"789\"}]}";
        public static String jsonuser = "{\"name\":\"xiaohong\",\"password\":\"654321\"}";
        public static String jsonlist = "[{\"name\":\"xiaohong\",\"password\":\"654321\"},{\"name\":\"xixi\",\"password\":\"789\"}]";       
 
        List list1 =  JSONObject.parseObject(jsonlist, List.class);//jsonlist转list
        Map map1 = JSONObject.parseObject(jsonmap, Map.class);//jsonmap转map