[java] How do I remove a specific element from a JSONArray?

I am building one app in which I request a PHP file from server. This PHP file returns a JSONArray having JSONObjects as its elements e.g.,

[ 
  {
    "uniqid":"h5Wtd", 
    "name":"Test_1", 
    "address":"tst", 
    "email":"[email protected]", 
    "mobile":"12345",
    "city":"ind"
  },
  {...},
  {...},
  ...
]

my code:

/* jArrayFavFans is the JSONArray i build from string i get from response.
   its giving me correct JSONArray */
JSONArray jArrayFavFans=new JSONArray(serverRespons);
for (int j = 0; j < jArrayFavFans.length(); j++) {
  try {
    if (jArrayFavFans.getJSONObject(j).getString("uniqid").equals(id_fav_remov)) {
      //jArrayFavFans.getJSONObject(j).remove(j); //$ I try this to remove element at the current index... But remove doesn't work here ???? $
      //int index=jArrayFavFans.getInt(j);
      Toast.makeText(getParent(), "Object to remove...!" + id_fav_remov, Toast.LENGTH_SHORT).show();
    }
  } catch (JSONException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }
}

How do I remove a specific element from this JSONArray?

 JSONArray jArray = new JSONArray();

    jArray.remove(position); // For remove JSONArrayElement

Note :- If remove() isn't there in JSONArray then...

API 19 from Android (4.4) actually allows this method.

Call requires API level 19 (current min is 16): org.json.JSONArray#remove

Right Click on Project Go to Properties

Select Android from left site option

And select Project Build Target greater then API 19

Hope it helps you.

We can use iterator to filter out the array entries instead of creating a new  Array. 

'public static void removeNullsFrom(JSONArray array) throws JSONException {
                if (array != null) {
                    Iterator<Object> iterator = array.iterator();
                    while (iterator.hasNext()) {
                        Object o = iterator.next();
                        if (o == null || o == JSONObject.NULL) {
                            iterator.remove();
                        }
                    }
                }
            }'

In case if someone returns with the same question for Android platform, you cannot use the inbuilt remove() method if you are targeting for Android API-18 or less. The remove() method is added on API level 19. Thus, the best possible thing to do is to extend the JSONArray to create a compatible override for the remove() method.

public class MJSONArray extends JSONArray {

    @Override
    public Object remove(int index) {

        JSONArray output = new JSONArray();     
        int len = this.length(); 
        for (int i = 0; i < len; i++)   {
            if (i != index) {
                try {
                    output.put(this.get(i));
                } catch (JSONException e) {
                    throw new RuntimeException(e);
                }
            }
        } 
        return output;
        //return this; If you need the input array in case of a failed attempt to remove an item.
     }
}

EDIT As Daniel pointed out, handling an error silently is bad style. Code improved.

public static JSONArray RemoveJSONArray( JSONArray jarray,int pos) {

JSONArray Njarray=new JSONArray();
try{
for(int i=0;i<jarray.length();i++){     
    if(i!=pos)
        Njarray.put(jarray.get(i));     
}
}catch (Exception e){e.printStackTrace();}
return Njarray;

}

i guess you are using Me version, i suggest to add this block of function manually, in your code (JSONArray.java) :

public Object remove(int index) {
    Object o = this.opt(index);
    this.myArrayList.removeElementAt(index);
    return o;
}

In java version they use ArrayList, in ME Version they use Vector.

To Remove some element from Listview in android then it will remove your specific element and Bind it to listview.

BookinhHistory_adapter.this.productPojoList.remove(position);

BookinhHistory_adapter.this.notifyDataSetChanged();

You can use reflection

A Chinese website provides a relevant solution: http://blog.csdn.net/peihang1354092549/article/details/41957369
If you don't understand Chinese, please try to read it with the translation software.

He provides this code for the old version:

public void JSONArray_remove(int index, JSONArray JSONArrayObject) throws Exception{
    if(index < 0)
        return;
    Field valuesField=JSONArray.class.getDeclaredField("values");
    valuesField.setAccessible(true);
    List<Object> values=(List<Object>)valuesField.get(JSONArrayObject);
    if(index >= values.size())
        return;
    values.remove(index);
}

In my case I wanted to remove jsonobject with status as non zero value, so what I did is made a function "removeJsonObject" which takes old json and gives required json and called that function inside the constuctor.

public CommonAdapter(Context context, JSONObject json, String type) {
        this.context=context;
        this.json= removeJsonObject(json);
        this.type=type;
        Log.d("CA:", "type:"+type);

    }

public JSONObject removeJsonObject(JSONObject jo){
        JSONArray ja= null;
        JSONArray jsonArray= new JSONArray();
        JSONObject jsonObject1=new JSONObject();

        try {
            ja = jo.getJSONArray("data");

        } catch (JSONException e) {
            e.printStackTrace();
        }
        for(int i=0; i<ja.length(); i++){
            try {

                if(Integer.parseInt(ja.getJSONObject(i).getString("status"))==0)
                {
                    jsonArray.put(ja.getJSONObject(i));
                    Log.d("jsonarray:", jsonArray.toString());
                }


            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
        try {
            jsonObject1.put("data",jsonArray);
            Log.d("jsonobject1:", jsonObject1.toString());

            return jsonObject1;
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return json;
    }