Java tutorial
/*! * The MIT License (MIT) * * Copyright(c) 2014 SF Toolworks <info@sftoolworks.com> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.sftoolworks.nfcoptions; import android.app.PendingIntent; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.content.SharedPreferences; import android.nfc.NdefMessage; import android.nfc.NdefRecord; import android.nfc.NfcAdapter; import android.nfc.Tag; import android.nfc.tech.Ndef; import android.os.Parcelable; import android.support.v7.app.ActionBarActivity; import android.os.Bundle; import android.util.Log; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.AdapterView; import android.widget.CheckBox; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.json.JSONTokener; import java.util.ArrayList; import java.util.Timer; import java.util.TimerTask; public class SelectActivity extends ActionBarActivity { protected NfcAdapter nfcAdapter = null; protected PendingIntent pendingIntent = null; protected Boolean handledIntent = false; protected Boolean launchIntent = true; protected final String CHECKBOX_STATE = "checkboxList"; protected final String KEY_STATE = "key"; protected String selectKey = null; private static final String TAG = SelectActivity.class.getName(); @Override protected void onPause() { nfcAdapter.disableForegroundDispatch(this); super.onPause(); } @Override protected void onResume() { super.onResume(); if (!handledIntent) { if (getIntent().getAction().equals(NfcAdapter.ACTION_NDEF_DISCOVERED)) { if (!launchIntent) { Log.d(TAG, "This is a second tap"); writeSelection(getIntent()); } } handledIntent = true; } nfcAdapter.enableForegroundDispatch(this, pendingIntent, new IntentFilter[] { new IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED) }, null); } protected void writeSelection(Intent intent) { ListView list = (ListView) findViewById(R.id.listView1); if (list.getCount() == 0) return; try { Object[] results = ((OptionListAdapter) list.getAdapter()).getCheckedValues(); JSONObject obj = new JSONObject(); JSONArray array = new JSONArray(); if (null != results) { for (Object result : results) array.put(result.toString()); } obj.put("selection", array); obj.put("key", selectKey); SharedPreferences sharedPref = getSharedPreferences(getString(R.string.preference_file_key), Context.MODE_PRIVATE); // android studio (0.5.1) decorates this line as an error (some // of the time, anyway) but it's not an error. String identifier = sharedPref.getString(getString(R.string.user_id_key), ""); if (identifier.length() > 0) obj.put("user", identifier); String json = obj.toString(0); String outbound = "\u0002en"; outbound += json; NdefRecord textRecord = new NdefRecord(NdefRecord.TNF_WELL_KNOWN, new byte[] { 'T' }, null, outbound.getBytes()); NdefMessage message = new NdefMessage(new NdefRecord[] { textRecord }); Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG); Ndef ndef = Ndef.get(tag); ndef.connect(); ndef.writeNdefMessage(message); ndef.close(); Toast.makeText(this, R.string.write_ok, Toast.LENGTH_LONG).show(); new Timer().schedule(new TimerTask() { @Override public void run() { finish(); } }, 1500); } catch (Exception e) { Log.d(TAG, e.toString()); String err = getString(R.string.tag_write_err) + "\n" + e.getMessage(); Toast.makeText(this, err, Toast.LENGTH_LONG).show(); } } @Override public void onRestoreInstanceState(Bundle savedInstanceState) { super.onRestoreInstanceState(savedInstanceState); ListView list = (ListView) findViewById(R.id.listView1); if (list.getCount() == 0) return; if (savedInstanceState.containsKey(CHECKBOX_STATE)) { boolean[] checkboxes = savedInstanceState.getBooleanArray(CHECKBOX_STATE); ((OptionListAdapter) (list.getAdapter())).restoreCheckState(checkboxes); } if (savedInstanceState.containsKey(KEY_STATE)) { selectKey = savedInstanceState.getString(KEY_STATE); } } @Override public void onSaveInstanceState(Bundle savedInstanceState) { ListView list = (ListView) findViewById(R.id.listView1); if (list.getCount() > 0) { savedInstanceState.putBooleanArray(CHECKBOX_STATE, ((OptionListAdapter) list.getAdapter()).getCheckState()); } if (null != selectKey) savedInstanceState.putString(KEY_STATE, selectKey); // Always call the superclass so it can save the view hierarchy state super.onSaveInstanceState(savedInstanceState); } @Override public void onNewIntent(Intent intent) { handledIntent = false; launchIntent = false; setIntent(intent); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_select); nfcAdapter = NfcAdapter.getDefaultAdapter(this); pendingIntent = PendingIntent.getActivity(this, 0, new Intent(this, this.getClass()).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0); Intent intent = getIntent(); Parcelable[] rawMessages = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES); String title = getString(R.string.default_select_title); TextView textViewBottom = (TextView) findViewById(R.id.textView2); textViewBottom.setText(""); if (rawMessages != null) { ArrayList<Object> entries = new ArrayList<Object>(); String data = null; for (Parcelable rawMessage : rawMessages) { NdefMessage message = (NdefMessage) rawMessage; NdefRecord[] records = message.getRecords(); if (records.length > 1) { byte[] bArray = records[1].getPayload(); byte languageLength = bArray[0]; languageLength++; // because of the length byte data = new String(bArray, languageLength, bArray.length - languageLength); } } try { JSONObject json = (JSONObject) new JSONTokener(data).nextValue(); if (json.has("title")) title = json.getString("title"); if (json.has("key")) selectKey = json.getString("key"); if (json.has("options")) { JSONArray arr = json.getJSONArray("options"); for (int i = 0; i < arr.length(); i++) { entries.add(parseJObject(arr.getJSONObject(i))); } } ListView list = (ListView) findViewById(R.id.listView1); list.setAdapter(new OptionListAdapter(this, entries.toArray())); list.setOnItemClickListener(new ListView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int index, long id) { CheckBox cb = (CheckBox) view.findViewById(R.id.optionListCheckBox); cb.setChecked(!cb.isChecked()); } }); textViewBottom.setText(getString(R.string.tap_again)); } catch (Exception e) { String message = getString(R.string.json_err); message += "\n"; message += e.getMessage(); Toast.makeText(this, message, Toast.LENGTH_LONG).show(); Log.d(TAG, getString(R.string.json_err)); Log.d(TAG, e.toString()); Log.d(TAG, data); } } else { title = getString(R.string.no_tag); } TextView msg = (TextView) findViewById(R.id.textView1); msg.setText(title); } protected Object parseJObject(JSONObject obj) throws JSONException { String[] elements = new String[3]; if (obj.has("title") && obj.has("label")) { elements[0] = obj.getString("title"); elements[1] = obj.getString("label"); if (obj.has("value")) elements[2] = obj.getString("value"); else elements[2] = obj.getString("title"); return elements; } else throw new JSONException("Missing required element "); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.select, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); if (id == R.id.action_settings) { Intent intent = new Intent(this, MainActivity.class); startActivity(intent); return true; } return super.onOptionsItemSelected(item); } }