实现java中的json数组(JSONArray) 根据某个共同字段 分组

Question

如何用java代码将下面的对象数组：[
    {"id":"1001","name":"值1","value":"111"},
    {"id":"1001","name":"值1","value":"11111"},
    {"id":"1002","name":"值2","value":"25462"},
    {"id":"1002","name":"值2","value":"23131"},
    {"id":"1002","name":"值2","value":"2315432"},
    {"id":"1003","name":"值3","value":"333333"}
]根据相同id字段分组，转换成下面这种形式：[
    {
        "id": "1001",       
        "data": [
            {"id": "1001", "name": "值1", "value": "111"},
            { "id": "1001", "name": "值1", "value": "11111"}
        ]
    },
    {
        "id": "1002",        
        "data": [
            { "id": "1002",  "name": "值2", "value": "25462" },
            { "id": "1002", "name": "值2", "value": "23131"},
            {"id": "1002", "name": "值2","value": "2315432" }
        ]
    },
    {
        "id": "1003",       
        "data": [
            {"id": "1003", "name": "值3", "value": "333333" }
        ]
    }
]

Answer 1

用fastjson或jackson把json转成对象，重新组装后再转成json

Answer 2

可否提供一段比较完整的java代码啊？非常感谢！

Answer 3

https://blog.csdn.net/zhang89xiao/article/details/51942614参考下这个吧,自己研究出来的才是自己的东西

Answer 4

看这个比较好https://blog.csdn.net/qq_34638435/article/details/80076878

Answer 5

就当做个练习题了，我采用fastjson，总感觉代码不够严谨，求大佬指点：    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.62</version>
    </dependency>
        String sourceStr = "[\n" +
                "    {\"id\":\"1001\",\"name\":\"值1\",\"value\":\"111\"},\n" +
                "    {\"id\":\"1001\",\"name\":\"值1\",\"value\":\"11111\"},\n" +
                "    {\"id\":\"1002\",\"name\":\"值2\",\"value\":\"25462\"},\n" +
                "    {\"id\":\"1002\",\"name\":\"值2\",\"value\":\"23131\"},\n" +
                "    {\"id\":\"1002\",\"name\":\"值2\",\"value\":\"2315432\"},\n" +
                "    {\"id\":\"1003\",\"name\":\"值3\",\"value\":\"333333\"}\n" +
                "]";
        JSONArray jsonArray = JSONArray.parseArray(sourceStr);
        Map<String, List<JSONObject>> map = new HashMap<String, List<JSONObject>>();
        String tempIdStr = "";
        List<JSONObject> list = null;
        for(Object obj : jsonArray){
            JSONObject jsonObject = (JSONObject) obj;
            tempIdStr = jsonObject.getString("id");
            if(map.containsKey(tempIdStr)){
                list = map.get(tempIdStr);
                list.add(jsonObject);
            }else{
                list = new ArrayList<JSONObject>();
                list.add(jsonObject);
                map.put(tempIdStr, list);
            }
        }
        List targetList = new ArrayList();
        Map targetMap = null;
        for(Map.Entry<String, List<JSONObject>> entry : map.entrySet()){
            targetMap = new HashMap();
            targetMap.put("id", entry.getKey());
            targetMap.put("data", entry.getValue());
            targetList.add(targetMap);
        }
        //String targetStr = JSONArray.toJSONString(targetList);
        String targetStr = JSONArray.toJSONString(targetList, SerializerFeature.PrettyFormat); //PrettyFormat用于美化输出
        System.out.println(targetStr);