需要引包:
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
pom.xml需要引入:
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.44</version>
</dependency>
<artifactId>fastjson</artifactId>
<version>1.2.44</version>
</dependency>
数据格式
//JSONObject的数据是用 { } 来表示的
{ "id":"123", "name":"张三", "age":"11"}
//JSONArray是由JSONObject组成的数组 用【】和{}来表示
[{ "id":"123", "name":"张三", "age":"11"},{ "id":"321", "name":"李四", "age":"21"}]
获取jsonArray中每一个JsonObject里的键对应的内容
1 String jsonstr = "[{"id":"123","name":"张三","age":"11"},{"id":"321", "name":"李四","age":"21"}]"; 2 JSONArray jsonArray = JSONArray.parseArray(jsonstr); 3 for (int i=0;i<jsonArray.size();i++) {//会循环两次 4 JSONObject jsonObject = jsonArray.getJSONObject(i); 5 String id = jsonObject.getString("id");//123,321 6 String name = jsonObject.getString("name");//张三,李四 7 String age = jsonObject.getString("age");//11,21 8 }
String转JsonObject
1 String configstr = "{"user1":{"u1":"1","u2":"3","u3":"1","u4":"0"},"user2":"","user3":""}"; 2 JSONObject jsonObject = JSONObject.parseObject(configstr);//string转json 3 String user1 = jsonObject.getString("user1");//获取user1的string类型的json 4 JSONObject jsonObject = JSONObject.parseObject(user1); 5 String u1 = jsonObjectin.getString("u1");
判断某个JsonObject中是否有某个键或值
1 jsonObject.containsKey()//判断jsonobject中是否包含某个键 2 jsonObject.containsValue()//判断jsonobject中是否包含某个值