如何在 Android Studio 中从没有字符串 ID 的解析 JSON 中获取字符串

Question

How do I get a string from Parse JSON with data like below?

My Data JSON:

[ 
   [ 
      "John Gorman",
      "3344764667200003",
      "Student",
      "2018-08-09 08:21:30.807"
   ],
   [ 
      "Andy William",
      "3403032311690003",
      "Student",
      "2018-08-09 08:21:30.807"
   ],
   [ 
      "Thomas Endry",
      "3408932311690078",
      "Student",
      "2018-08-09 08:21:30.807"
   ],
   [ 
      "Robet Calm",
      "3403077711690890",
      "Student",
      "2018-08-09 08:21:30.807"
   ]
]

I use the code below, then to get the string what I have to do, I really don't understand, if there is help, I really need to thank you.

try {
    JSONObject object = new JSONObject(result);
    JSONArray jsonArray = object.getJSONArray("");
    //JSONArray jsonArray = new JSONArray(result);

    for (int i = 0; i < jsonArray.length(); i++) {
        JSONObject c = jsonArray.getJSONObject(i);
        String name = c.getString("What should I write here");
        System.out.println(c.getString(""));
    }

I want to get the string from Parse JSON that I have

How do I get a string for listview, for example:

John Gorman
3344764667200003
Student

Andy William
3403032311690003
Student

Thomas Endry
3408932311690078
Student

Robet Calm
3403077711690890
Student

Answer 1

A couple of things are wrong with the posted code. See my comments inline:

 JSONObject object = new JSONObject(result); ^^^^^^^^^^^^^^^^^^^^^^ the content of result is not an object, but an array. JSONArray jsonArray = object;getJSONArray(""); ^^ a proper JSON document had better not have empty keys; //JSONArray jsonArray = new JSONArray(result). ^^^^^^^^^^^^^^^^^^^^^ this was actually going in the right direction; for (int i = 0. i < jsonArray;length(), i++) { JSONObject c = jsonArray.getJSONObject(i); ^^^^^^^^^^^^^^^^^^^^^^^^^^ the i-th element of the array is not an object, but an array!

Fixing the issues above:

JSONArray jsonArray = new JSONArray(result);

for (int i = 0; i < jsonArray.length(); i++) {
  JSONArray subArray = jsonArray.getJSONArray(i);
  for (int j = 0; j < subArray.length(); j++) {
    System.out.println(subArray.getString(j));
  }
  System.out.println();
}

Answer 2

You can do something like this:

try {
    JSONObject object = new JSONObject(result);
    JSONArray jsonArray = object.getJSONArray("");
    //JSONArray jsonArray = new JSONArray(result);

    for (int i = 0; i < jsonArray.length(); i++) {
        JSONObject c = jsonArray.getJSONObject(i);
        String name = c.getString(0);
        String id = c.getString(1);
        String student = c.getString(2);
        // and so on ... This index refers to the index number on the string inside json object
        System.out.println(name);
    }

Hope this answers your query.

Answer 3

You are receiving a JSONArray not object so use the below code.

for(int i=0;i<jsonarray.length();i++){
   JSONArray array=jsonarray.getJSONArray(i);
     for(int j=0;j<array.length();j++){
     Log.d(TAG,array.getString(j));
   }
}

Answer 4

Following method will construct a list of string from the given Json. You can pass that list in the adapter of the list view.

public List<String> getList (String result) throws JSONException {
        List<String> list = new LinkedList<>();
        JSONArray jsonArray = new JSONArray(result);
        for (int i = 0; i < jsonArray.length(); i++) {
            JSONArray arr = jsonArray.getJSONArray(i);
            StringBuilder sb = new StringBuilder();
            for(int j=0;j<arr.length(); j++) {
                sb.append(arr.getString(j));
                if(j<arr.length()-1) sb.append("\n");
            }
            list.add(sb.toString());
        }
        return list;
}