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());
}