I am trying to finish this program and i am stuck. This is my first program and now it wont work. I keep getting this error when i add query.fromLocalDatastore(); The code runs fine until i try to get it from the local storage. This is telling me there is nothing there for it to retrieve and i don't know why. When i added my test data it worked fine but when i try to pull data from another table i get the error above. Apparently when i added the test data the server synced with the local datastore. Now it is not. Can someone tell me what I did wrong?
public class DataHolder extends Application {
int age;
#Override
public void onCreate() {
super.onCreate();
Parse.enableLocalDatastore(getApplicationContext());
Parse.initialize(this,key, key);
ParseUser.enableAutomaticUser();
ParseACL defaultACL = new ParseACL();
ParseACL.setDefaultACL(defaultACL, true);
}
public class MainActivity extends ActionBarActivity implements Disclaimer.DisclaimerListener {
protected void continueToRun() {
spinner1.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
public void onItemSelected(AdapterView<?> adapter, View v, int x, long lng) {
final ParseQuery<ParseObject> query = ParseQuery.getQuery("Phone_Numbers");
query.fromLocalDatastore();
if (x == 1) {
final Intent intent = new Intent(getBaseContext(), Protocol_Template.class);
query.fromLocalDatastore();
query.whereEqualTo("objectId", "uGANULyrdL");
startActivity(intent);
}
}
public class Protocol_Template extends Activity {
DataHolder global;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_protocol__template);
final TextView protocol = (TextView) findViewById(R.id.txt02);
findViewById(R.id.btn2timesUpperLeft);
final ParseQuery<ParseObject> query = ParseQuery.getQuery("Phone_Numbers");
query.fromLocalDatastore();
query.getFirstInBackground(new GetCallback<ParseObject>() {
public void done(ParseObject object, ParseException e) {
if (e == null) {
final String protocols = object.get("PhoneNumber").toString();
protocol.setText(protocols);
} else {
protocol.setText(e.getMessage());
}
}
});
}
Related
In my Android app I use AAC.
Here my activity:
public class AddTraderActivity extends AppCompatActivity {
AddTraderViewModel addTraderViewModel;
private static final String TAG = AddTraderActivity.class.getName();
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
AddTraderActivityBinding binding = DataBindingUtil.setContentView(this, R.layout.add_trader_activity);
binding.setHandler(this);
init();
}
private void init() {
ViewModelProvider viewViewModelProvider = ViewModelProviders.of(this);
addTraderViewModel = viewViewModelProvider.get(AddTraderViewModel.class);
Observer<String> () {
#Override
public void onChanged (String message){
Debug.d(TAG, "onChanged: message = " + message);
Toast.makeText(AddTraderActivity.this, message, Toast.LENGTH_LONG).show();
}
});
}
public void onClickStart() {
EditText baseEditText = findViewById(R.id.baseEditText);
EditText quoteEditText = findViewById(R.id.quoteEditText);
addTraderViewModel.doClickStart(baseEditText.getText().toString(), quoteEditText.getText().toString());
}
}
Here my ViewModel:
public class AddTraderViewModel extends AndroidViewModel {
private MutableLiveData<String> messageLiveData = new MutableLiveData<>();
private static final String TAG = AddTraderViewModel.class.getName();
public AddTraderViewModel(#NonNull Application application) {
super(application);
}
public void doClickStart(String base, String quote) {
Debug.d(TAG, "doClickStart: ");
if (base.trim().isEmpty() || quote.trim().isEmpty()) {
String message = getApplication().getApplicationContext().getString(R.string.please_input_all_fields);
messageLiveData.setValue(message);
return;
}
}
public LiveData<String> getMessageLiveData() {
return messageLiveData;
}
}
So when I click on button on Activity call method onClickStart()
If any fields is empty the show toast. In the activity call method:
onChanged (String message)
Nice. It's work fine.
But the problem is, when I rotate the device in the activity method onChanged(String message) is called AGAIN and as result show toast. This happened on every rotation.
Why?
This is the expected behaviour. If you want to avoid this you must set message = "" and keep an empty check before showing the toast.
A better way to use it is something like Event Wrapper or SingleLiveEvent
Highly recommend you to read this article. This explains why you are facing this and what are your options in detail.
I am using Room Database with LiveData , but my Local Database is updating too fast as per our requirement and at the same time i have to reload my recycler view .instead of calling notifyDataSetChanged() to adapter , i am trying to use DiffUtil , but is crashing or not reloading properly , this is uncertain .
i am following this tutorial :
Tutorials Link here
MyAdapter :
public class SwitchGridAdapter extends RecyclerView.Adapter<SwitchGridAdapter.ViewHolder> {
private List<Object> allItemsList;
private LayoutInflater mInflater;
private OnItemClickListener mClickListener;
private Context context;
private Queue<List<Object>> pendingUpdates =
new ArrayDeque<>();
// data is passed into the constructor
public SwitchGridAdapter(Context context,List<Appliance> applianceList,List<ZmoteRemote> zmoteRemoteList) {
this.mInflater = LayoutInflater.from(context);
this.context = context;
allItemsList = new ArrayList<>();
if (applianceList!=null) allItemsList.addAll(applianceList);
if (zmoteRemoteList!=null)allItemsList.addAll(zmoteRemoteList);
}
// inflates the cell layout from xml when needed
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = mInflater.inflate(R .layout.switch_grid_item, parent, false);
return new ViewHolder(view);
}
// binds the data to the textview in each cell
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// Doing some update with UI Elements
}
// total number of cells
#Override
public int getItemCount() {
return allItemsList.size();
}
// stores and recycles views as they are scrolled off screen
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnLongClickListener {
TextView myTextView;
ImageView imgSwitch;
ViewHolder(View itemView) {
super(itemView);
myTextView = (TextView) itemView.findViewById(R.id.txtSwitchName);
imgSwitch = (ImageView) itemView.findViewById(R.id.imgSwitchStatus);
itemView.setOnClickListener(this);
itemView.setOnLongClickListener(this);
}
#Override
public void onClick(View view) {
// handling click
}
#Override
public boolean onLongClick(View view) {
return true;
}
// convenience method for getting data at click position
Object getItem(int id) {
return allItemsList.get(id);
}
// allows clicks events to be caught
public void setClickListener(OnItemClickListener itemClickListener) {
this.mClickListener = itemClickListener;
}
// parent activity will implement this method to respond to click events
public interface OnItemClickListener {
void onItemClick(View view, int position);
void onItemLongPressListner(View view, int position);
}
// ✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅
// From This Line Reloading with Diff Util is Done .
//✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅✅
public void setApplianceList( List<Appliance> applianceList,List<ZmoteRemote> zmoteRemoteList)
{
if (allItemsList == null)
allItemsList = new ArrayList<>();
List<Object> newAppliances = new ArrayList<>();
if (applianceList!=null) newAppliances.addAll(applianceList);
updateItems(newAppliances);
}
// when new data becomes available
public void updateItems(final List<Object> newItems) {
pendingUpdates.add(newItems);
if (pendingUpdates.size() > 1) {
return;
}
updateItemsInternal(newItems);
}
// This method does the heavy lifting of
// pushing the work to the background thread
void updateItemsInternal(final List<Object> newItems) {
final List<Object> oldItems = new ArrayList<>(this.allItemsList);
final Handler handler = new Handler();
new Thread(new Runnable() {
#Override
public void run() {
final DiffUtil.DiffResult diffResult =
DiffUtil.calculateDiff(new DiffUtilHelper(oldItems, newItems));
handler.post(new Runnable() {
#Override
public void run() {
applyDiffResult(newItems, diffResult);
}
});
}
}).start();
}
// This method is called when the background work is done
protected void applyDiffResult(List<Object> newItems,
DiffUtil.DiffResult diffResult) {
dispatchUpdates(newItems, diffResult);
}
// This method does the work of actually updating
// the backing data and notifying the adapter
protected void dispatchUpdates(List<Object> newItems,
DiffUtil.DiffResult diffResult) {
// ❌❌❌❌❌❌ Next Line is Crashing the app ❌❌❌❌❌
pendingUpdates.remove();
dispatchUpdates(newItems, diffResult);
if (pendingUpdates.size() > 0) {
updateItemsInternal(pendingUpdates.peek());
}
}
}
Observing LiveData
public void setUpAppliancesListLiveData()
{
if (applianceObserver!=null)
{
applianceObserver = null;
}
Log.e("Appliance Fetch","RoomName:"+this.roomName);
applianceObserver = new Observer<List<Appliance>>() {
#Override
public void onChanged(#Nullable List<Appliance> applianceEntities) {
// Log.e("Appliance Result","Appliance List \n\n:"+applianceEntities.toString());
new Thread(new Runnable() {
#Override
public void run() {
List<Appliance> applianceListTemp = applianceEntities;
zmoteRemoteList = new ArrayList<>(); //appDelegate.getDatabase().zmoteRemoteDao().getRemoteList(roomName);
// Sort according to name
Collections.sort(applianceListTemp, new Comparator<Appliance>() {
#Override
public int compare(Appliance item, Appliance t1) {
String s1 = item.getSwitchName();
String s2 = t1.getSwitchName();
return s1.compareToIgnoreCase(s2);
}
});
if(getActivity()!=null) {
getActivity().runOnUiThread(new Runnable() {
#Override
public void run() {
applianceList = applianceListTemp;
mRecyclerView.getRecycledViewPool().clear();
adapter.setApplianceList(applianceList,zmoteRemoteList);
}
});
}
}
}).start();
}
};
appDelegate.getDatabase().applianceDao().getApplinaceListByRoomName(this.roomName).observe(this, applianceObserver);
}
I'm saying i'm not a programmer but a guy who has been learning to program with java for a while. I hope to find the solution to my problem here. I'm trying to program my home automation system and remote control and to do this, I chose to use Kryonet. My problem is that every time I send the data to the server, the client opens a new connection. It's been 3 weeks since googlo and I try to figure out how to do it but with no results.
Every help is seriously appreciated. This is my code. Thank you.
This code work in my home network.
Sorry for my english...
public class MainActivity extends AppCompatActivity {
Button button;
String IP = "";
EditText editText;
TextView textView;
EditText editText3;
public static String msg_response;
public static String msg_request;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final Handler handler = new MyHandler();
button = (Button) findViewById(R.id.button);
editText = (EditText) findViewById(R.id.editText);
editText3 = (EditText) findViewById(R.id.editText3);
textView = (TextView) findViewById(R.id.textView);
int MY_PERMISSIONS_REQUEST_INTERNET = 1;
int MY_PERMISSIONS_REQUEST_ACCESS_NETWORK_STATE = 1;
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.INTERNET},
MY_PERMISSIONS_REQUEST_INTERNET);
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_NETWORK_STATE},
MY_PERMISSIONS_REQUEST_ACCESS_NETWORK_STATE);
int MY_PERMISSIONS_REQUEST_ACCESS_WIFY_STATE = 1;
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_WIFI_STATE},
MY_PERMISSIONS_REQUEST_ACCESS_WIFY_STATE);
textView.setText(msg_response);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
try {
msg_request = valueOf(editText3.getText().toString());
} catch (Exception e) {
e.printStackTrace();
}
MyThread myThread = new MyThread(handler);
myThread.start();
}
});
}
private class MyHandler extends Handler {
#Override
public void handleMessage(Message msg) {
Bundle bundle = msg.getData();
if (bundle.containsKey("msg da server")) {
String msgin = bundle.getString("msg da server");
textView.setText(msgin);
}
}
}
class MyThread extends Thread {
private Handler handler;
public MyThread(Handler handler) {
this.handler = handler;
}
public void run() {
System.out.println("MyThread running");
Client client = new Client();
client.start();
Kryo kryoClient = client.getKryo();
kryoClient.register(SampleRequest.class);
kryoClient.register(SampleResponse.class);
try {
client.connect(5000, "192.168.0.101", 54555, 54666);
} catch (IOException e) {
e.printStackTrace();
}
client.addListener(new Listener() {
public void received(Connection connection, Object object) {
if (object instanceof SampleResponse) {
SampleResponse response = (SampleResponse) object;
System.out.println(response.text);
msg_response = response.text.toString();
invia_activity(msg_response);
}
}
});
SampleRequest request = new SampleRequest();
request.text = msg_request;
client.sendTCP(request);
}
private void invia_activity(String invia) {
Message msg = handler.obtainMessage();
Bundle b = new Bundle();
b.putString("msg da server", "" + invia);
msg.setData(b);
handler.sendMessage(msg);
}
}
}
I dont have an direct solution, but i have an tutorial for it. I used the same one. So there the connections keeps open, and you can send as many packets as you need. Its without audio, but the code works well. After that you can experiment with the code. It works fine for me. This is the tutorial
I hope i can help you with this.
EDIT:
Maybe you can make an
public static Connection conn;
and you could use that object again and again as your connection to the server.
I am developing extending WebSocketBehavior in order to send logging data to a client.. have generated the logging handler and it fires as and when needed.
I am having trouble understanding how exactly to push the log entries to the clients and update the console panel. I already know the onMessage method is what I need to override with the console taking the WeSocketRequestHandler as an argument along with the message I want to send. How exactly do I get the onMessage to fire properly?? Here is the code I am using:
public class LogWebSocketBehavior extends WebSocketBehavior {
private static final long serialVersionUID = 1L;
Console console;
private Handler logHandler;
private Model model;
public LogWebSocketBehavior(Console console) {
super();
configureLogger();
this.console = console;
}
private void configureLogger() {
Logger l = Logger.getLogger(AppUtils.loggerName);
logHandler = getLoggerHandler();
l.addHandler(logHandler);
}
#Override
protected void onMessage(WebSocketRequestHandler handler, TextMessage message) {
console.info(handler, model.getObject());
}
private Handler getLoggerHandler() {
return new Handler() {
#Override
public void publish(LogRecord record) {
model.setObject(record);
}
#Override
public void flush() {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
#Override
public void close() throws SecurityException {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
};
}
private Collection<IWebSocketConnection> getConnectedClients() {
IWebSocketConnectionRegistry registry = new SimpleWebSocketConnectionRegistry();
return registry.getConnections(getApplication());
}
private void sendToAllConnectedClients(String message) {
Collection<IWebSocketConnection> wsConnections = getConnectedClients();
for (IWebSocketConnection wsConnection : wsConnections) {
if (wsConnection != null && wsConnection.isOpen()) {
try {
wsConnection.sendMessage("test");
} catch (IOException e) {
}
}
}
}
}
The logger works as I want it to, providing messages as needed, but I cannot find how to actually fire the onMessage method to update my console. Any help is appreciated...
#onMessage() is called by Wicket whenever the browser pushes a message via Wicket.WebSocket.send("some message").
It is not very clear but I guess you need to push messages from the server to the clients (the browsers). If this is the case then you need to get a handle to IWebSocketRequestHandler and use its #push(String) method. You can do this with WebSocketSettings.Holder.get(Application.get()).getConnectionRegistry().getConnection(...).push("message").
Here is the class working as I need. Thank you Martin!!
public class LogWebSocketBehavior extends WebSocketBehavior {
private static final long serialVersionUID = 1L;
Console console;
private Handler logHandler;
private IModel model;
public LogWebSocketBehavior(Console console, IModel model) {
super();
configureLogger();
this.console = console;
this.model = model;
}
private void configureLogger() {
Logger l = Logger.getLogger(AppUtils.loggerName);
logHandler = getLoggerHandler();
l.addHandler(logHandler);
}
#Override
protected void onPush(WebSocketRequestHandler handler, IWebSocketPushMessage message) {
super.onPush(handler, message);
console.info(handler, model);
}
private Handler getLoggerHandler() {
return new Handler() {
#Override
public void publish(LogRecord record) {
model.setObject(record);
sendToAllConnectedClients(record.toString());
}
#Override
public void flush() {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
#Override
public void close() throws SecurityException {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
};
}
private Collection<IWebSocketConnection> getConnectedClients() {
IWebSocketConnectionRegistry registry = new SimpleWebSocketConnectionRegistry();
return registry.getConnections(getApplication());
}
private void sendToAllConnectedClients(String message) {
IWebSocketConnectionRegistry registry = new SimpleWebSocketConnectionRegistry();
WebSocketPushBroadcaster b = new WebSocketPushBroadcaster(registry);
IWebSocketPushMessage msg = new Message();
b.broadcastAll(getApplication(), msg);
}
class Message implements IWebSocketPushMessage {
public Message(){
}
}
}
Hi I'm trying to retrieve a linkedhashset from the Google datastore but nothing seems to happen. I want to display the results in a Grid using GWT on a page. I have put system.out.println() in all the classes to see where I go wrong but it only shows one and I don't recieve any errors. I use 6 classes 2 in the server package(ContactDAOJdo/ContactServiceImpl) and 4 in the client package(ContactService/ContactServiceAsync/ContactListDelegate/ContactListGui). I hope someone can explain why this isn't worken and point me in the right direction.
public class ContactDAOJdo implements ContactDAO {
#SuppressWarnings("unchecked")
#Override
public LinkedHashSet<Contact> listContacts() {
PersistenceManager pm = PmfSingleton.get().getPersistenceManager();
String query = "select from " + Contact.class.getName();
System.out.print("ContactDAOJdo: ");
return (LinkedHashSet<Contact>) pm.newQuery(query).execute();
}
}
public class ContactServiceImpl extends RemoteServiceServlet implements ContactService{
private static final long serialVersionUID = 1L;
private ContactDAO contactDAO = new ContactDAOJdo() {
#Override
public LinkedHashSet<Contact> listContacts() {
LinkedHashSet<Contact> contacts = contactDAO.listContacts();
System.out.println("service imp "+contacts);
return contacts;
}
}
#RemoteServiceRelativePath("contact")
public interface ContactService extends RemoteService {
LinkedHashSet<Contact> listContacts();
}
public interface ContactServiceAsync {
void listContacts(AsyncCallback<LinkedHashSet <Contact>> callback);
}
public class ListContactDelegate {
private ContactServiceAsync contactService = GWT.create(ContactService.class);
ListContactGUI gui;
void listContacts(){
contactService.listContacts(new AsyncCallback<LinkedHashSet<Contact>> () {
public void onFailure(Throwable caught) {
gui.service_eventListContactenFailed(caught);
System.out.println("delegate "+caught);
}
public void onSuccess(LinkedHashSet<Contact> result) {
gui.service_eventListRetrievedFromService(result);
System.out.println("delegate "+result);
}
});
}
}
public class ListContactGUI {
protected Grid contactlijst;
protected ListContactDelegate listContactService;
private Label status;
public void init() {
status = new Label();
contactlijst = new Grid();
contactlijst.setVisible(false);
status.setText("Contact list is being retrieved");
placeWidgets();
}
public void service_eventListRetrievedFromService(LinkedHashSet<Contact> result){
System.out.println("1 service eventListRetreivedFromService "+result);
status.setText("Retrieved contactlist list");
contactlijst.setVisible(true);
this.contactlijst.clear();
this.contactlijst.resizeRows(1 + result.size());
int row = 1;
this.contactlijst.setWidget(0, 0, new Label ("Voornaam"));
this.contactlijst.setWidget(0, 1, new Label ("Achternaam"));
for(Contact contact: result) {
this.contactlijst.setWidget(row, 0, new Label (contact.getVoornaam()));
this.contactlijst.setWidget(row, 1, new Label (contact.getVoornaam()));
row++;
System.out.println("voornaam: "+contact.getVoornaam());
}
System.out.println("2 service eventListRetreivedFromService "+result);
}
public void placeWidgets() {
System.out.println("placewidget inside listcontactgui" + contactlijst);
RootPanel.get("status").add(status);
RootPanel.get("contactlijst").add(contactlijst);
}
public void service_eventListContactenFailed(Throwable caught) {
status.setText("Unable to retrieve contact list from database.");
}
}
It could be the query returns a lazy list. Which means not all values are in the list at the moment the list is send to the client. I used a trick to just call size() on the list (not sure how I got to that solution, but seems to work):
public LinkedHashSet<Contact> listContacts() {
final PersistenceManager pm = PmfSingleton.get().getPersistenceManager();
try {
final LinkedHashSet<Contact> contacts =
(LinkedHashSet<Contact>) pm.newQuery(Contact.class).execute();
contacts.size(); // this triggers to get all values.
return contacts;
} finally {
pm.close();
}
}
But I'm not sure if this is the best practice...