java - 比较Json Array的对象并显示具有相同参数的对象

Question

我有一个包含四个对象的 json 数组。

{"name":"Ram", "email":"ram@gmail.com", "age":23}, 
{"name":"Shyam", "email":"shyam23@gmail.com", "age":28},  
{"name":"John", "email":"john@gmail.com", "age":23},    
{"name":"Bob", "email":"bob32@gmail.com", "age":41}   

我想迭代 json 对象并显示具有相同年龄的人的详细信息。我正在使用Java。我是 json 新手。任何人都可以建议如何继续。我正在使用 json.org 库。

我已经走到这一步了:

public static void main(String[] args) {
    String text="{\"name\":\"Ram\", \"email\":\"ram@gmail.com\", \"age\":23}"
            + "{\"name\":\"Shyam\", \"email\":\"shyam23@gmail.com\", \"age\":28}"
            + "{\"name\":\"John\", \"email\":\"john@gmail.com\", \"age\":23}"
            + "{\"name\":\"Bob\", \"email\":\"bob32@gmail.com\", \"age\":41}";
    String changed=text.toString();
    int pos=changed.lastIndexOf("}");
    String change=changed.substring(0,pos );
    change=change.replace("}", "},");
    String res=change.concat("}"); 
    String msg="["+res+"]";
    JSONArray json=new JSONArray(msg);
    for(int i=0;i<json.length();i++){
        JSONObject obj= json.getJSONObject(i);
    }
}

Answer 1

public class JSONThing {

    public void change() {

        String text = "{\"name\":\"Ram\", \"email\":\"ram@gmail.com\", \"age\":23}"
            + "{\"name\":\"Shyam\", \"email\":\"shyam23@gmail.com\", \"age\":28}"
            + "{\"name\":\"John\", \"email\":\"john@gmail.com\", \"age\":23}"
            + "{\"name\":\"Bob\", \"email\":\"bob32@gmail.com\", \"age\":41}";
        String changed = text.toString();
        int pos = changed.lastIndexOf("}");
        String change = changed.substring(0, pos);
        change = change.replace("}", "},");
        String res = change.concat("}");
        String msg = "[" + res + "]";
        JSONArray json;
        try {
            json = new JSONArray(msg);
            Map<Integer, List<JSONObject>> mapp = new HashMap<>();
                for (int i = 0; i < json.length(); i++) {
                    JSONObject obj = json.getJSONObject(i);
                    List<JSONObject> list = mapp.getOrDefault(obj.getInt("age"),new ArrayList<>());
                    list.add(obj);
                    mapp.put(obj.getInt("age"),list);
            }

        System.out.println(mapp);
        for (Entry<Integer, List<JSONObject>> entry : mapp.entrySet())
        {
          ListIterator<JSONObject> i=entry.getValue().listIterator();
          System.out.println(entry.getKey());
            //System.out.println(entry.getKey() + "/" + entry.getValue());
          while(i.hasNext()){
              System.out.println(i.next());
          }
        }

    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

public static void main(String[] args) {
    JSONThing j  = new JSONThing();
    j.change();
}

}

实现这个，它将打印所有具有相同年龄的用户。