String bestimmten Wert heraus holen

  try {
                items = json.getJSONArray(TAG_ITEMS);
                for (int i = 0; i < items.length(); i++) {
                    JSONObject c = items.getJSONObject(i);
                    final String betreff = c.getString(TAG_BETREFF);
                    final String beschreibung = c.getString(TAG_BESCHREIBUNG);
                    String datum = c.getString(TAG_DATUM);


                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put(TAG_BETREFF, betreff);
                    map.put(TAG_BESCHREIBUNG, beschreibung);
                    map.put(TAG_DATUM, datum);
                    osList.add(map);
                    list = (ListView) findViewById(R.id.listView);
                    final ListAdapter adapter = new SimpleAdapter(MyActivity.this,
                            osList,
                            R.layout.list_item,
                            new String[]{TAG_BETREFF, TAG_BESCHREIBUNG, TAG_DATUM},
                            new int[]{R.id.filename, R.id.tvBeschreibung, R.id.tvDatum});

                    list.setAdapter(adapter);

                    list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
                        @Override
                        public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                                                long arg3) {


                            String o = list.getAdapter().getItem(arg2).toString();

                            Toast.makeText(getApplicationContext(), o,
                                    Toast.LENGTH_SHORT).show();


                        }


                    });