在JSON

Question

我想得到的结果：

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

要向JSON添加新数据，我尝试了这个：

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。

如何删除JSON数据取决于ID的值？

感谢的。

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());
   }
   

<强>输出：

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

1. 要将新JSONObject添加到现有JSONArray，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());
   }
   

<强>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"}]

1. 要从JSONObject移除JSONArray，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());
   }
   

<强>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"}]

希望这会对你有所帮助。

Answer 2

json的根对象是一个数组，所以你应该使用JSONArray，而不是JSONObject。

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