转换复杂的JSON对象为Map对象

本文在参考https://www.cnblogs.com/Animation-programmer/p/7997621.html后，在原来代码上做了改动（添加了对内层json的递归解析），写成了工具方法

一、问题描述

现有如下调用接口返回的json数据，

需要将其转换为Map对象，如果json中含有数组，则在对应的Map对象中嵌套ArrayList。解析结果如下图所示：

二、代码实现

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

import java.util.*;

public class JSONUtil {

/**
* 将json对象转换为HashMap
* @param json
* @return
*/
public static Map<String, Object> parseJSON2Map(JSONObject json) {
Map<String, Object> map = new HashMap<String, Object>();
// 最外层解析
for (Object k : json.keySet()) {
Object v = json.get(k);
// 如果内层还是json数组的话，继续解析
if (v instanceof JSONArray) {
List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
Iterator<JSONObject> it = ((JSONArray) v).iterator();
while (it.hasNext()) {
JSONObject json2 = it.next();
list.add(parseJSON2Map(json2));
}
map.put(k.toString(), list);
} else if (v instanceof JSONObject) {
// 如果内层是json对象的话，继续解析
map.put(k.toString(), parseJSON2Map((JSONObject) v));
} else {
// 如果内层是普通对象的话，直接放入map中
map.put(k.toString(), v);
}
}
return map;
}

/**
* 将json字符串转换为Map
* @param jsonStr
* @return
*/
public static Map<String, Object> parseJSONstr2Map(String jsonStr) {
JSONObject json = JSONObject.fromObject(jsonStr);
Map<String, Object> map = parseJSON2Map(json);
return map;
}
}

测试json字符串转Map的方法，符合预期结果：

public static void main(String[] args) {
Map<String, Object> myresult = JSONUtil.parseJSONstr2Map("{" +
""data": {" +
""studentList": [{" +
""scourse": {" +
""cname": "语文,数学,英语"," +
""cscore": "93,95,98"" +
"}," +
""sname": "张三"," +
""sage": "20"," +
""sid": "101"" +
"}," +
"{" +
""scourse": {" +
""cname": "物理,化学,生物"," +
""cscore": "92,93,97"" +
"}," +
""sname": "李四"," +
""sage": "30"," +
""sid": "102"" +
"}]" +
"}," +
""resultCode": "1"" +
"}");
System.out.println(myresult);
}
补充：生成测试数据的代码

public static void main(String[] args) {
List<Map<String, Object>> studentList = new ArrayList<Map<String, Object>>();
Map<String, Object> student = new HashMap<String, Object>(){{
put("sid", "101");
put("sname", "张三");
put("sage", "20");
put("scourse", new HashMap<String, String>(){{
put("cname", "语文,数学,英语");
put("cscore", "93,95,98");
}});
}};
studentList.add(student);
student = new HashMap<String, Object>(){{
put("sid", "102");
put("sname", "李四");
put("sage", "30");
put("scourse", new HashMap<String, String>(){{
put("cname", "物理,化学,生物");
put("cscore", "92,93,97");
}});
}};
studentList.add(student);
Map<String, Object> resultMap = new HashMap<String, Object>(){{
put("data", new HashMap<String, Object>(){{
put("studentList", studentList);
}});
put("resultCode", "1");
}};
System.out.println(JSONObject.fromObject(resultMap).toString());
}