How to write into a json file in Android

Question

I am using a bundled json file in my application. I want to read and write data into the json file. I have a listview which displays the currently available data in json and an edittext into which user enters data. That data has to be written into the json. How to do this?

This is my code...

 public class MainActivity extends Activity { String myjsonstring; ArrayList<Data> web = new ArrayList<Data>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); JsonParser(); } private void JsonParser() { // Reading text file from assets folder StringBuffer sb = new StringBuffer(); BufferedReader br = null; try { br = new BufferedReader(new InputStreamReader(getAssets().open( "single.json"))); String temp; while ((temp = br.readLine()) != null) sb.append(temp); } catch (IOException e) { e.printStackTrace(); } finally { try { br.close(); // stop reading } catch (IOException e) { e.printStackTrace(); } } myjsonstring = sb.toString(); // Try to parse JSON try { JSONObject jsonObjMain = new JSONObject(myjsonstring); JSONArray jsonArray = jsonObjMain.getJSONArray("message"); for (int i=0; i<jsonArray.length(); i++) { JSONObject jsonObj = jsonArray.getJSONObject(i); // Getting data from individual JSONObject Data data = new Data(jsonObj.getString("name") , jsonObj.getString("msg")); web.add(data); } final customtest1 adapter = new customtest1(MainActivity.this,R.layout.list_single,web); final ListView list = (ListView)findViewById(R.id.list); list.setAdapter(adapter); list.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Toast.makeText(MainActivity.this, "TEST.........", Toast.LENGTH_SHORT).show(); adapter.notifyDataSetChanged(); } }); //Send activity...... final EditText et = (EditText)findViewById(R.id.EditText1); final Button imb=(Button)findViewById(R.id.btn_send); imb.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { String str = et.getText().toString(); Data store = new Data(et.getText().toString()); web.add(store); Toast.makeText(MainActivity.this, "You entered...."+store, Toast.LENGTH_SHORT).show(); et.setText(" "); scrollMyListViewToBottom(); adapter.notifyDataSetChanged(); } //Screen auto scrollup.... private void scrollMyListViewToBottom() { list.post(new Runnable() { @Override public void run() { // Select the last row so it will scroll into view... list.setSelection(adapter.getCount() - 1); } }); }}); } catch (JSONException e) { e.printStackTrace(); } } }

You cannot edit files added as resources, make a copy of it in your application data folder — Marco Acierno
– Marco Acierno, Commented Apr 7, 2014 at 7:05

penkzhou · Accepted Answer · 2014-04-07 07:05:52Z

In my opinion,you could parse the jsonarray from the exist file,then add the new data to the old jasonarray,then write the new data to the exist file.

Waqar Ahmed · Accepted Answer · 2014-04-07 09:39:45Z

0

you cannot edit file in asset folder at runtime .load file into memory and then try this method to write to internal memory :

private void writeToFile(String jsonData) { try { OutputStreamWriter outputStreamWriter = new OutputStreamWriter(openFileOutput("single.json", Context.MODE_PRIVATE)); outputStreamWriter.write(jsonData); outputStreamWriter.close(); } catch (IOException e) { Log.e("Exception", "File write failed: " + e.toString()); } }