java - 在 JSON 中追加或删除数据

Question

我想要得到的结果:

[
{"id":1,"name":"example1","description":"An example"},
{"id":2, "name":"example2","description":"Just another example"}, 
... ]

要将新数据添加到 JSON，我尝试了以下操作:

String jsonDataString = ALL MY JSON DATA HERE;
JSONObject mainObject = new JSONObject(jsonDataString);
JSONObject valuesObject = new JSONObject();
JSONArray list = new JSONArray();
valuesObject.put("id", "3");
valuesObject.put("name", "example3");
valuesObject.put("description", "Yet another example");
list.put(valuesObject);
mainObject.accumulate("", list);

但我没有得到正确的结果。

如何根据 ID 的值删除 JSON 数据？

谢谢。

Answer 1

1. 要构建新的 JSONArray，您可以使用以下代码:

   try {
   
       JSONArray jsonArray = new JSONArray();
   
       // Object 1
       JSONObject jsonObject1 = new JSONObject();
       jsonObject1.put("id", 1);
       jsonObject1.put("name", "example1");
       jsonObject1.put("description", "An example");
   
       // Object 2
       JSONObject jsonObject2 = new JSONObject();
       jsonObject2.put("id", 2);
       jsonObject2.put("name", "example2");
       jsonObject2.put("description", "Just another example");
   
       // Add Object 1 & 2 JSONArray
       jsonArray.put(jsonObject1);
       jsonArray.put(jsonObject2);
   
   
       Log.d("JSON", "JSON: " + jsonArray.toString());
   
   } catch (final JSONException e) {
       Log.e("FAILED", "Json parsing error: " + e.getMessage());
   }
   

输出:

D/JSON: JSON: [{"id":1,"name":"example1","description":"An example"},{"id":2,"name":"example2","description":"Just another example"}]

要将新的 JSONObject 添加到现有的 JSONArray 中，您可以使用以下代码:

// Your Existing JSONArray
// [{"id":1,"name":"example1","description":"An example"},
//  {"id":2, "name":"example2","description":"Just another example"}]

String jsonDataString = "[{\"id\":1,\"name\":\"example1\",\"description\":\"An example\"},{\"id\":2,\"name\":\"example2\",\"description\":\"Just another example\"}]";

try {

    JSONArray jsonArray = new JSONArray(jsonDataString);

    // Object 3
    JSONObject jsonObject3 = new JSONObject();
    jsonObject3.put("id", 3);
    jsonObject3.put("name", "example3");
    jsonObject3.put("description", "Third example");

    // Add Object 3 JSONArray
    jsonArray.put(jsonObject3);

    Log.d("JSON", "JSON: " + jsonArray.toString());

} catch (final JSONException e) {
    Log.e("FAILED", "Json parsing error: " + e.getMessage());
}

输出:

D/JSON: JSON: [{"id":1,"name":"example1","description":"An example"},{"id":2,"name":"example2","description":"Just another example"},{"id":3,"name":"example3","description":"Third example"}]

要从 JSONArray 中删除 JSONObject，您可以使用以下代码:

// Your Existing JSONArray
// [{"id":1,"name":"example1","description":"An example"},
//  {"id":2,"name":"example2","description":"Just another example"},
//  {"id":3,"name":"example3","description":"Third example"}]  

String jsonDataString = "[{\"id\":1,\"name\":\"example1\",\"description\":\"An example\"},{\"id\":2,\"name\":\"example2\",\"description\":\"Just another example\"},{\"id\":3,\"name\":\"example3\",\"description\":\"Third example\"}]";

try {

    JSONArray jsonArray = new JSONArray(jsonDataString);

    Log.d("JSON", "JSON before Remove: " + jsonArray.toString());

    // Remove Object id = 2
    int removeId = 2;

    for (int i = 0; i < jsonArray.length(); i++)
    {
        JSONObject object = jsonArray.getJSONObject(i);

        if (object.has("id") && !object.isNull("id")) {

            int id = object.getInt("id");

            if (id == removeId)
            {
                jsonArray.remove(i);
                break;
            }
        }
    }

    Log.d("JSON", "JSON After Remove: " + jsonArray.toString());

} catch (final JSONException e) {
    Log.e("FAILED", "Json parsing error: " + e.getMessage());
}

输出:

D/JSON: JSON Before Remove: [{"id":1,"name":"example1","description":"An example"},{"id":2,"name":"example2","description":"Just another example"},{"id":3,"name":"example3","description":"Third example"}]

D/JSON: JSON After Remove: [{"id":1,"name":"example1","description":"An example"},{"id":3,"name":"example3","description":"Third example"}]

希望这对您有帮助。