how to convert json data into map string string

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public String readFromSD(){
    File newFolder = new File(Environment.getExternalStorageDirectory(), "Contacts");
    File file = new File(newFolder,"/Allcontact.txt");
    StringBuilder data = new StringBuilder();       
    try 
    {
        BufferedReader br = new BufferedReader(new FileReader(file));
        String line;
        while ((line = br.readLine()) != null) {
            data.append(line);
            data.append('\n');
        }           
        txtData.setText(data.toString());

        try
        {

        JSONObject jobj = new JSONObject(data.toString());          
        JSONArray arr = new JSONArray(jobj);            
        //Toast.makeText(getApplicationContext(),"File Contents ==> " +arr.toString(),Toast.LENGTH_SHORT).show();
        Map m = toMap(jobj);
        m.get(jobj);

       txtData.setText(m.toString());
        }catch(Exception e){
            e.getMessage();
        }           
    }
    catch (IOException e) {
    }

how to convert json data into map string string