JAVAFX Exception in thread "JavaFX Application Thread" - javafx

I was trying to add 10 records to my table when the "Page-down" button is pressed, the same for the "Down-arrow" is pressed. I keep getting the Exception error while I'm trying to add more records.
I am using a cursor mapping for each table.
this.setOnKeyPressed(new EventHandler<KeyEvent>() {
#Override
public void handle(KeyEvent event) {
switch (event.getCode()){
case PAGE_DOWN:
try {
if (resultSet.getRow() == numberOfRows) break;
if (((CanvasTableView) event.getSource()).getSelectionModel().getSelectedCells().get(0).getRow() > resultSet.getRow() - 17) {
Object object = table.getSelectionModel().selectedItemProperty().get(); // get the focus cell
int index = table.getSelectionModel().selectedIndexProperty().get(); // get the focus cell
int cursor_index = buffer_paging.get(table); //cursor index
resultSet.absolute(cursor_index);
System.out.println("Row: " + resultSet.getRow());
ArrayList<Row> data = dataBaseArrayListByNumber(rs, rs.getMetaData().getColumnCount(), 17,cursor_index);
table.getItems().addAll(data);
table.refresh();
System.out.println("Fuck yuval: " + ((CanvasTableView) event.getSource()).getSelectionModel().getSelectedCells().get(0).getRow());
buffer_paging.put(table, cursor_index+10);
System.err.println("Row: " + resultSet.getRow());
System.out.println(index);
}
}
catch (Exception e) {
e.printStackTrace();
}
break;
case PAGE_UP: System.err.println("Page up is pressed"); break;
case DOWN:
try {
if (resultSet.getRow() == numberOfRows) break;
int focus_cell = ((CanvasTableView) event.getSource()).getSelectionModel().getSelectedCells().get(0).getRow();
int cursor_index = buffer_paging.get(table); //cursor index
int rowNumber = table.getItems().size();
if (focus_cell == rowNumber-1 || focus_cell== rowNumber){
ArrayList<Row> data = dataBaseArrayListByNumber(rs, rs.getMetaData().getColumnCount(), 1,cursor_index);
table.getItems().addAll(data);
table.refresh();
int new_cursor = cursor_index+1;
buffer_paging.put(table, new_cursor);
}
}
catch (Exception e) {
e.printStackTrace();
}
break;
}
});
Exception:
Exception in thread "JavaFX Application Thread" java.lang.IndexOutOfBoundsException: Index 16 out of bounds for length 16
at java.base/jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64)
at java.base/jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70)
at java.base/jdk.internal.util.Preconditions.checkIndex(Preconditions.java:248)
at java.base/java.util.Objects.checkIndex(Objects.java:373)
at java.base/java.util.ArrayList.get(ArrayList.java:425)
at javafx.base/com.sun.javafx.collections.ObservableListWrapper.get(ObservableListWrapper.java:89)
at javafx.base/com.sun.javafx.collections.VetoableListDecorator.get(VetoableListDecorator.java:306)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Node.processCSS(Node.java:9537)
at javafx.graphics/javafx.scene.Scene.doCSSPass(Scene.java:569)
at javafx.graphics/javafx.scene.Scene$ScenePulseListener.pulse(Scene.java:2471)
at javafx.graphics/com.sun.javafx.tk.Toolkit.lambda$runPulse$2(Toolkit.java:413)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at javafx.graphics/com.sun.javafx.tk.Toolkit.runPulse(Toolkit.java:412)
at javafx.graphics/com.sun.javafx.tk.Toolkit.firePulse(Toolkit.java:439)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:563)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.pulse(QuantumToolkit.java:543)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.pulseFromQueue(QuantumToolkit.java:536)
at javafx.graphics/com.sun.javafx.tk.quantum.QuantumToolkit.lambda$runToolkit$11(QuantumToolkit.java:342)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:174)
at java.base/java.lang.Thread.run(Thread.java:830)
My function for adding data:
private ArrayList dataBaseArrayListByNumber(ResultSet resultSet, int columnCount,int count,int cursor_index) throws SQLException {
ArrayList data = new ArrayList<>();
resultSet.absolute(cursor_index+1);
while (count>0&& resultSet.next()) {
HashMap<String, Double> columnData = new HashMap<String, Double>();
for (int i = 1; i < columnCount + 1; i++) {
String s = String.valueOf(i);
double x = resultSet.getDouble(i);
columnData.put(String.valueOf(i), resultSet.getDouble(i));
}
Row row = new Row(columnData);
data.add(row);
count--;
}
return data;
}
Anyone has an idea why I'm keep getting those exceptions?

Related

Task: how to be notified when the task is "finished"

... that is after all its properties - including its value - are updated?
The use-case is a Task that
"collects" items into an ObservableList which is the result of the call method
the list should be set as value when the task is "finished", no matter if normally or cancelled
A snippet of the Task implementation (complete example at end):
#Override
protected ObservableList<Rectangle> call() throws Exception {
ObservableList<Rectangle> results = FXCollections.observableArrayList();
for (int i=0; i<=count; i++) {
// do fill list
//...
try {
Thread.sleep(200);
} catch (InterruptedException interrupted) {
if (isCancelled()) {
// do update value on cancelled
updateValue(results);
break;
}
}
}
return results;
}
It's intended usage:
bind the itemsProperty of a tableView to the valueProperty
unbind on "finished"
My approach was to listen to its state property and unbind on state changes to SUCCEEDED or CANCELLED. The former works just fine, the latter doesn't because at the time of receiving the cancelled, the value is not yet updated and consequently the items not set.
// working ... but when to unbind?
table.itemsProperty().bind(task.valueProperty());
task.stateProperty().addListener((src, ov, nv) -> {
if (Worker.State.SUCCEEDED == nv ) {
// this is fine because implementation in TaskCallable first
// updates the value (with the result it got from T call())
// then updates state
LOG.info("succeeded" + task.getValue());
table.itemsProperty().unbind();
} else if (Worker.State.CANCELLED == nv) {
LOG.info("receiving cancelled " + task.getValue());
// can't unbind here, value not yet updated
// table.itemsProperty().unbind();
}
});
So in case of cancelled, this leaves me with either a property that's still bound or an empty table. Feels like I'm doing something wrong. Or core Task impl is not as useful as expected? It would mean that we simply can't bind to the value property (nor any of the others like progress) due to being unable to safely cleanup (using table items here is just an example, because it's easy to see, same for all types of properties).
Question is, how to do it correctly/overcome the limitation?
The complete example:
public class TaskValueBinding extends Application {
private Parent createListPane() {
Task<ObservableList<Rectangle>> task = createListTask();
Thread thread = new Thread(task);
thread.setDaemon(true);
TableView<Rectangle> table = new TableView<>();
TableColumn<Rectangle, Double> xCol = new TableColumn<>("X");
xCol.setCellValueFactory(new PropertyValueFactory<>("x"));
TableColumn<Rectangle, Double> yCol = new TableColumn<>("Y");
yCol.setCellValueFactory(new PropertyValueFactory<>("y"));
table.getColumns().addAll(xCol, yCol);
// working ... but when to unbind?
table.itemsProperty().bind(task.valueProperty());
task.stateProperty().addListener((src, ov, nv) -> {
if (Worker.State.SUCCEEDED == nv ) {
// this is fine because implementation in TaskCallable first
// updates the value (with the result it got from T call())
// then updates state
LOG.info("succeeded" + task.getValue());
table.itemsProperty().unbind();
} else if (Worker.State.CANCELLED == nv) {
LOG.info("receiving cancelled " + task.getValue());
// can't unbind here, value not yet updated
// table.itemsProperty().unbind();
}
});
Label messageLabel = new Label("Message: ");
Label message = new Label();
message.textProperty().bind(task.messageProperty());
Label progressAsText = new Label();
Label progressLabel = new Label("Progress: ");
progressAsText.textProperty().bind(task.progressProperty().asString());
ProgressBar progress = new ProgressBar();
progress.progressProperty().bind(task.progressProperty());
Button start = new Button("Start");
start.setOnAction(e -> {
start.setDisable(true);
thread.start();
});
Button cancel = new Button("Cancel");
cancel.setOnAction(e -> task.cancel());
cancel.disableProperty().bind(task.runningProperty().not());
int row = 0;
GridPane grid = new GridPane();
grid.add(table, 0, row++, 20, 1);
grid.add(messageLabel, 0, row);
grid.add(message, 1, row++);
grid.add(progressLabel, 0, row);
grid.add(progressAsText, 1, row++);
grid.add(progress, 0, row++, 2, 1);
grid.add(start, 0, row);
grid.add(cancel, 1, row++);
return grid;
}
private Task<ObservableList<Rectangle>> createListTask() {
Task<ObservableList<Rectangle>> task = new Task<ObservableList<Rectangle>>() {
#Override
protected ObservableList<Rectangle> call() throws Exception {
updateMessage("Creating Rectangles ...");
ObservableList<Rectangle> results = FXCollections.observableArrayList();
String message = "finished";
int count = 10;
for (int i=0; i<=count; i++) {
if (isCancelled()) {
updateValue(results);
// when do we get here?
message = "cancelled";
break;
}
Rectangle r = new Rectangle(10, 10);
r.setX(10 * i);
results.add(r);
updateProgress(i, count);
// Now block the thread for a short time, but be sure
// to check the interrupted exception for cancellation!
try {
Thread.sleep(200);
} catch (InterruptedException interrupted) {
if (isCancelled()) {
updateValue(results);
message = "interrupted";
break;
}
}
}
updateMessage(message);
return results;
}
};
return task;
}
#Override
public void start(Stage stage) throws Exception {
stage.setScene(new Scene(createListPane()));
stage.setTitle(FXUtils.version());
stage.show();
}
public static void main(String[] args) {
launch(args);
}
#SuppressWarnings("unused")
private static final Logger LOG = Logger
.getLogger(TaskValueBinding.class.getName());
}
Cancelling the task immediately triggers an update of the state property. If canceled from the application thread Platfrom.runLater is not used for this purpose but the call of the cancel method updates the state immediately. This results in the state being changed before any updateValue call updates the value property using Platform.runLater.
Task is not designed to allow partial results so you need to implement custom logic to accommodate for this. Depending on your needs you could subclass Task to trigger a custom event when the task completes in any way.
public abstract class PartialResultTask<T> extends Task<T> {
// handler triggered after last change of value
private Runnable onDone;
public Runnable getOnDone() {
return onDone;
}
public void setOnDone(Runnable onDone) {
this.onDone = onDone;
}
protected abstract T calculateResult() throws Exception;
private void onDone() {
if (onDone != null) {
Platform.runLater(onDone);
}
}
#Override
protected final T call() throws Exception {
try {
T result = calculateResult();
updateValue(result); // update value to the final value
onDone();
return result;
} catch (Exception ex) {
onDone();
throw ex;
}
}
}
private PartialResultTask<ObservableList<Rectangle>> createListTask() {
PartialResultTask<ObservableList<Rectangle>> task = new PartialResultTask<ObservableList<Rectangle>>() {
#Override
protected ObservableList<Rectangle> calculateResult() throws Exception {updateMessage("Creating Rectangles ...");
ObservableList<Rectangle> results = FXCollections.observableArrayList();
int count = 10;
for (int i = 0; !isCancelled() && i <= count; i++) {
Rectangle r = new Rectangle(10, 10);
r.setX(10 * i);
results.add(r);
updateProgress(i, count);
// Now block the thread for a short time, but be sure
// to check the interrupted exception for cancellation!
try {
Thread.sleep(200);
} catch (InterruptedException interrupted) {
}
}
updateMessage(isCancelled() ? "canceled" : "finished");
return results;
}
};
return task;
}
task.setOnDone(() -> {
table.itemsProperty().unbind();
});
task.stateProperty().addListener((src, ov, nv) -> {
if (Worker.State.SUCCEEDED == nv) {
// this is fine because implementation in TaskCallable first
// updates the value (with the result it got from T call())
// then updates state
LOG.info("succeeded" + task.getValue());
} else if (Worker.State.CANCELLED == nv) {
LOG.info("receiving cancelled " + task.getValue());
}
});

Fail to connect to camera service at sometimes

Am calling my camera function as separate fragment during first 2 times of calling the class camera is opening but if am calling the class third time app is crashing.
private int findFrontFacingCamera() {
int cameraId = 0;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
cameraId = i;
cameraFront = true;
break;
}
}
return cameraId;
}
private int findBackFacingCamera() {
int cameraId = -1;
//Search for the back facing camera
//get the number of cameras
int numberOfCameras = Camera.getNumberOfCameras();
//for every camera check
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_BACK) {
cameraId = i;
cameraFront = false;
break;
}
}
return cameraId;
}
public void onResume() {
super.onResume();
if (!hasCamera(myContext)) {
Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG);
toast.show();
finish();
}
if (mCamera == null) {
//if the front facing camera does not exist
if (findFrontFacingCamera() < 0) {
Toast.makeText(getActivity().getApplicationContext(), "No front facing camera found.", Toast.LENGTH_LONG).show();
switchCamera.setVisibility(View.GONE);
}
mCamera = Camera.open(findFrontFacingCamera());
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
}
logcat
01-19 10:56:15.164 11477-11477/com.example.siva.prep E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.example.siva.prep, PID: 11477
java.lang.RuntimeException: Fail to connect to camera service
at android.hardware.Camera.native_setup(Native Method)
at android.hardware.Camera.<init>(Camera.java:393)
at android.hardware.Camera.open(Camera.java:347)
at com.example.siva.prep.Selfie.onResume(Selfie.java:146)
It's showing error on the following line in "onResume()" method:
mCamera = Camera.open(findFrontFacingCamera());
Here is the full my code am using:
public class Selfie extends Fragment implements OnClickListener {
private Camera mCamera;
private CameraPreview mPreview;
private PictureCallback mPicture;
private Button capture, switchCamera;
private Context myContext;
private LinearLayout cameraPreview;
private boolean cameraFront = false;
Bitmap bmp;
ImageView iv;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_selfie, container, false);
// getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
iv=(ImageView) view.findViewById(R.id.image);
myContext = getActivity().getApplicationContext();
getActivity().setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
cameraPreview = (LinearLayout) view.findViewById(R.id.camera_preview);
mPreview = new CameraPreview(myContext, mCamera);
cameraPreview.addView(mPreview);
ImageView capture = (ImageView) view.findViewById(R.id.button_capture);
capture.setOnClickListener(captrureListener);
ImageView switchCamera = (ImageView) view.findViewById(R.id.button_ChangeCamera);
switchCamera.setOnClickListener(switchCameraListener);
ImageView button1 = (ImageView) view.findViewById(R.id.back);
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
FreeFragment fragment2 = new FreeFragment();
FragmentManager fragmentManager = getFragmentManager();
android.support.v4.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.container, fragment2);
fragmentTransaction.commit();
}
});
getSupportActionBar().hide();
return view;
}
private ActionBar getSupportActionBar() {
return ((AppCompatActivity) getActivity()).getSupportActionBar();
}
#Override
public void onClick(View v) {
}
private int findFrontFacingCamera() {
int cameraId = 0;
// Search for the front facing camera
int numberOfCameras = Camera.getNumberOfCameras();
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
cameraId = i;
cameraFront = true;
break;
}
}
return cameraId;
}
private int findBackFacingCamera() {
int cameraId = -1;
//Search for the back facing camera
//get the number of cameras
int numberOfCameras = Camera.getNumberOfCameras();
//for every camera check
for (int i = 0; i < numberOfCameras; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
if (info.facing == CameraInfo.CAMERA_FACING_BACK) {
cameraId = i;
cameraFront = false;
break;
}
}
return cameraId;
}
public void onResume() {
super.onResume();
if (!hasCamera(myContext)) {
Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG);
toast.show();
finish();
}
if (mCamera == null) {
//if the front facing camera does not exist
if (findFrontFacingCamera() < 0) {
Toast.makeText(getActivity().getApplicationContext(), "No front facing camera found.", Toast.LENGTH_LONG).show();
switchCamera.setVisibility(View.GONE);
}
mCamera = Camera.open(findFrontFacingCamera());
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
}
private void finish() {
}
OnClickListener switchCameraListener = new OnClickListener() {
#Override
public void onClick(View v) {
//get the number of cameras
int camerasNumber = Camera.getNumberOfCameras();
if (camerasNumber >= 1) {
//release the old camera instance
//switch camera, from the front and the back and vice versa
releaseCamera();
chooseCamera();
} else {
Toast toast = Toast.makeText(myContext, "Sorry, your phone has only one camera!", Toast.LENGTH_LONG);
toast.show();
}
}
};
public void chooseCamera() {
// if the camera preview is the front
if (cameraFront) {
int cameraId = findBackFacingCamera();
if (cameraId <= 0) {
//open the backFacingCamera
//set a picture callback
//refresh the preview
mCamera = Camera.open(cameraId);
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
} else
{
int cameraId = findFrontFacingCamera();
if (cameraId >= 0) {
//open the backFacingCamera
//set a picture callback
//refresh the preview
mCamera = Camera.open(cameraId);
mPicture = getPictureCallback();
mPreview.refreshCamera(mCamera);
}
}
}
#Override
public void onPause() {
super.onPause();
//when on Pause, release camera in order to be used from other applications
releaseCamera();
}
private boolean hasCamera(Context context) {
//check if the device has camera
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
return true;
} else {
return false;
}
}
private PictureCallback getPictureCallback() {
PictureCallback picture = new PictureCallback() {
#Override
public void onPictureTaken(byte[] data, Camera camera) {
//make a new picture file
File pictureFile = getOutputMediaFile();
if (pictureFile == null) {
return;
}
try {
//write the file
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
Toast toast = Toast.makeText(myContext, "Picture saved: " + pictureFile.getName(), Toast.LENGTH_LONG);
iv.setImageURI(Uri.fromFile(pictureFile));
//Intent intent = new Intent(AndroidCameraExample.this,Fina.class);
String stringUri;
stringUri = pictureFile.toString();
//intent.putExtra("imagePath", stringUri);
//startActivity(intent);
FreeFragment ldf = new FreeFragment ();
Bundle args = new Bundle();
args.putString("Image", stringUri);
ldf.setArguments(args);
Log.d("Passing image", String.valueOf(args));
getFragmentManager().beginTransaction().add(R.id.container, ldf).commit();
toast.show();
} catch (FileNotFoundException e) {
} catch (IOException e) {
}
//refresh camera to continue preview
mPreview.refreshCamera(mCamera);
}
};
return picture;
}
//make picture and save to a folder
public static File getOutputMediaFile() {
//make a new file directory inside the "sdcard" folder
File mediaStorageDir = new File("/sdcard/", "JCG Camera");
//if this "JCGCamera folder does not exist
if (!mediaStorageDir.exists()) {
//if you cannot make this folder return
if (!mediaStorageDir.mkdirs()) {
return null;
}
}
//take the current timeStamp
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
File mediaFile;
//and make a media file:
mediaFile = new File(mediaStorageDir.getPath() + File.separator + "IMG_" + timeStamp + ".jpg");
return mediaFile;
}
OnClickListener captrureListener = new OnClickListener() {
#Override
public void onClick(View v) {
mCamera.takePicture(null, null, mPicture);
}
};
private void releaseCamera() {
// stop and release camera
if (mCamera != null) {
mCamera.release();
mCamera = null;
}
}
}
Irrespective of the reason, not obtaining Camera handle is a case that needs to be handled with proper error handling. In the current case in your Pause handler, is the Camera instance being released ? Check for proper usage at http://developer.android.com/training/basics/activity-lifecycle/pausing.html

Error in audio recording WAV

I have two methods that record audio every 10 minutes, alternating each method, properly recorded during the first 6 or 7 hours, but then I generates large files to twice normal to hear hear bad but only happens with a method other Normal still recording. I use to record WaveInEnvent since the method is inside a thread, I think problem is in OnDataAvailable.
Here the code used:
wavein = new WaveInEvent();
wavein.Dispose();
wavein.DeviceNumber = 0;
wavein.NumberOfBuffers = 11;
wavein.BufferMilliseconds = 1000;
wavein.WaveFormat = new WaveFormat(8000, 16, 2);
wavein.DataAvailable += OnDataAvailable;
wavein.RecordingStopped += OnRecordingStopped;
writer = new WaveFileWriter(outfilename, wavein.WaveFormat);
bufferedWaveProvider = new BufferedWaveProvider(wavein.WaveFormat);
bufferedWaveProvider.DiscardOnBufferOverflow = true;
wavein.StartRecording();
private void OnDataAvailable(object sender, WaveInEventArgs e)
{
if (this.InvokeRequired)
{
//Debug.WriteLine("Data Available");
this.BeginInvoke(new EventHandler<WaveInEventArgs>(OnDataAvailable), sender, e);
}
else
{
if (writer != null)
{
try
{
for (int i = 0; i < e.BytesRecorded; i += 2)
{
short sample = (short)((e.Buffer[i + 1] << 8) | e.Buffer[i + 0]);
float sample32 = sample / 32768f;
writer.WriteByte(e.Buffer[i + 0]);
writer.WriteByte(e.Buffer[i + 1]);
}
}
catch (Exception ex)
{
// Log error
}
}
}
}

Huge amount of packet drops and latency faced in netty

I am using netty 3.5.11 with Jdk 1.7 on Ubuntu to receive a large amount of updates of stocks rates at a very high frequency. The message format being sent is JSON. The data is subscribed from topic on a redis server. There is a Subscriber for each symbol. The channel object is passed to multiple Subscribers and on receiving the data it is written to the client.
Now the amount of data received is around 25,000 records in 2 minutes. Each record size is on an average around 500 bytes long.
During test runs around 7500/8000 records were dropped because the channel was not writable.
How do i avoid this. ?
I also noticed that the latency increases systematically leading to updates being received after a long period. This happened when i I used Bufferedwritehandler to avoid packet drops.
Here are the options that i set on bootstrap.
executionHandler = new ExecutionHandler(
new OrderedMemoryAwareThreadPoolExecutor(Runtime.getRuntime().availableProcessors() * 2, 1000000, 10000000, 100,
TimeUnit.MILLISECONDS));
serverBootStrap.setPipelineFactory(new ChannelPipelineFactory()
{
#Override
public ChannelPipeline getPipeline() throws Exception
{
return Channels.pipeline(new PortUnificationServerHandler(getConfiguration(), executionHandler));
}
});
serverBootStrap.setOption("child.tcpNoDelay", true);
serverBootStrap.setOption("tcpNoDelay", true);
serverBootStrap.setOption("child.keepAlive", true);
serverBootStrap.setOption("child.reuseAddress", true);
//setting buffer size can improve I/O
serverBootStrap.setOption("child.sendBufferSize", 16777216);
serverBootStrap.setOption("receiveBufferSize", 16777216);//1048576);
// better to have an receive buffer predictor
serverBootStrap.setOption("receiveBufferSizePredictorFactory", new AdaptiveReceiveBufferSizePredictorFactory(1024, 1024 * 16, 16777216));//1048576));
//if the server is sending 1000 messages per sec, optimum write buffer water marks will
//prevent unnecessary throttling, Check NioSocketChannelConfig doc
serverBootStrap.setOption("backlog", 1000);
serverBootStrap.setOption("sendBufferSize", 16777216);//1048576);
serverBootStrap.setOption("writeBufferLowWaterMark", 1024 * 1024 * 25);
serverBootStrap.setOption("writeBufferHighWaterMark", 1024 * 1024 * 50);
The pipeline and handlers class
public class PortUnificationServerHandler extends FrameDecoder
{
private AppConfiguration appConfiguration;
private final ExecutionHandler executionHandler;
public PortUnificationServerHandler(AppConfiguration pAppConfiguration, ExecutionHandler pExecutionHandler)
{
appConfiguration = pAppConfiguration;
this.executionHandler = pExecutionHandler;
}
#Override
protected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception
{
String lRequest = buffer.toString(CharsetUtil.UTF_8);
if (ConnectionServiceHelper.isValidJSON(lRequest))
{
ObjectMapper lObjectMapper = new ObjectMapper();
StringReader lStringReader = new StringReader(lRequest);
JsonNode lNode = lObjectMapper.readTree(lStringReader);
if (lNode.get(Constants.REQUEST_TYPE).asText().trim().equalsIgnoreCase(Constants.LOGIN_REQUEST))
{
JsonNode lDataNode1 = lNode.get(Constants.REQUEST_DATA);
LoginRequest lLogin = lObjectMapper.treeToValue(lDataNode1, LoginRequest.class);
if (lLogin.getCompress() != null)
{
if (lLogin.getCompress().trim().equalsIgnoreCase(Constants.COMPRESS_FLAG_TRUE))
{
enableJSON(ctx);
enableGzip(ctx);
ctx.getPipeline().remove(this);
}
else
{
enableJSON(ctx);
ctx.getPipeline().remove(this);
}
}
else
{
enableJSON(ctx);
ctx.getPipeline().remove(this);
}
}
}
// Forward the current read buffer as is to the new handlers.
return buffer.readBytes(buffer.readableBytes());
}
private void enableJSON(ChannelHandlerContext ctx)
{
ChannelPipeline pipeline = ctx.getPipeline();
boolean lHandlerExists = pipeline.getContext("bufferedwriter") != null;
if (!lHandlerExists)
{
pipeline.addFirst("bufferedwriter", new MyBufferedWriteHandler()); // 80960
}
boolean lHandlerExists = pipeline.getContext("framer") != null;
if (!lHandlerExists)
{
pipeline.addLast("framer", new DelimiterBasedFrameDecoder(65535,
new ChannelBuffer[]
{
ChannelBuffers.wrappedBuffer(
new byte[]
{
'\n'
})
}));
}
lHandlerExists = pipeline.getContext("decoder") != null;
if (!lHandlerExists)
{
pipeline.addLast("decoder", new StringDecoder(CharsetUtil.UTF_8));
}
lHandlerExists = pipeline.getContext("encoder") != null;
if (!lHandlerExists)
{
pipeline.addLast("encoder", new StringEncoder(CharsetUtil.UTF_8));
}
lHandlerExists = pipeline.getContext("executor") != null;
if (!lHandlerExists)
{
pipeline.addLast("executor", executionHandler);
}
lHandlerExists = pipeline.getContext("handler") != null;
if (!lHandlerExists)
{
pipeline.addLast("handler", new ConnectionServiceUpStreamHandler(appConfiguration));
}
lHandlerExists = pipeline.getContext("unite") != null;
if (!lHandlerExists)
{
pipeline.addLast("unite", new PortUnificationServerHandler(appConfiguration, executionHandler));
}
}
private void enableGzip(ChannelHandlerContext ctx)
{
ChannelPipeline pipeline = ctx.getPipeline();
//pipeline.remove("decoder");
//pipeline.addLast("decoder", new MyStringDecoder(CharsetUtil.UTF_8, true));
//pipeline.addLast("compress", new CompressionHandler(80, "gzipdeflater"));
boolean lHandlerExists = pipeline.getContext("encoder") != null;
if (lHandlerExists)
{
pipeline.remove("encoder");
}
lHandlerExists = pipeline.getContext("gzipdeflater") != null;
if (!lHandlerExists)
{
pipeline.addBefore("executor", "gzipdeflater", new ZlibEncoder(ZlibWrapper.GZIP));
}
lHandlerExists = pipeline.getContext("lengthprepender") != null;
if (!lHandlerExists)
{
pipeline.addAfter("gzipdeflater", "lengthprepender", new LengthFieldPrepender(4));
}
}
}
The BufferedWriterHandler
public class MyBufferedWriteHandler extends BufferedWriteHandler
{
private final AtomicLong bufferSize = new AtomicLong();
final Logger logger = LoggerFactory.getLogger(getClass());
public MyBufferedWriteHandler() {
// Enable consolidation by default.
super(true);
}
#Override
public void writeRequested(ChannelHandlerContext ctx, MessageEvent e) throws Exception
{
ChannelBuffer data = (ChannelBuffer) e.getMessage();
if (e.getChannel().isWritable())
{
long newBufferSize = bufferSize.get();
// Flush the queue if it gets larger than 8KiB.
if (newBufferSize > 0)
{
flush();
bufferSize.set(0);
}
ctx.sendDownstream(e);
}
else
{
logger.warn( "Buffering data for : " + e.getChannel().getRemoteAddress() );
super.writeRequested(ctx, e);
bufferSize.addAndGet(data.readableBytes());
}
}
#Override
public void channelInterestChanged(ChannelHandlerContext ctx, ChannelStateEvent e) throws Exception
{
if (e.getChannel().isWritable())
{
flush();
}
}
The function used in the Subscriber class to write data
public void writeToClient(Channel pClientChannel, String pMessage) throws IOException
{
String lMessage = pMessage;
if (pClientChannel.isWritable())
{
lMessage += Constants.RESPONSE_DELIMITER;
pClientChannel.write(lMessage);
}
else
{
logger.warn(DroppedCounter++ + " droppped : " + pMessage);
}
}
I have implemented some of the suggestions that i read on stackoverflow and other sites. But i have not been successfull in resolving this issue.
Kindly suggest or advice as to what am i missing ?
Thanks

BlackBerry - Exception when sending SMS

The code below should send a text message to a mobile number. It currently fails to work properly.
When the program attempts a message, the following error is reported:
Blocking operation not permitted on event dispatch thread
I created a separate thread to execute the SMS code, but I am still observing the same exception.
What am I doing wrong?
class DummyFirst extends MainScreen {
private Bitmap background;
private VerticalFieldManager _container;
private VerticalFieldManager mainVerticalManager;
private HorizontalFieldManager horizontalFldManager;
private BackGroundThread _thread;
CustomControl buttonControl1;
public DummyFirst() {
super();
LabelField appTitle = new LabelField("Dummy App");
setTitle(appTitle);
background = Bitmap.getBitmapResource("HomeBack.png");
_container = new VerticalFieldManager(Manager.NO_VERTICAL_SCROLL
| Manager.NO_VERTICAL_SCROLLBAR) {
protected void paint(Graphics g) {
// Instead of these next two lines, draw your bitmap
int y = DummyFirst.this.getMainManager()
.getVerticalScroll();
g.clear();
g.drawBitmap(0, 0, background.getWidth(), background
.getHeight(), background, 0, 0);
super.paint(g);
}
protected void sublayout(int maxWidth, int maxHeight) {
int width = background.getWidth();
int height = background.getHeight();
super.sublayout(width, height);
setExtent(width, height);
}
};
mainVerticalManager = new VerticalFieldManager(
Manager.NO_VERTICAL_SCROLL |
Manager.NO_VERTICAL_SCROLLBAR) {
protected void sublayout(int maxWidth, int maxHeight) {
int width = background.getWidth();
int height = background.getHeight();
super.sublayout(width, height);
setExtent(width, height);
}
};
HorizontalFieldManager horizontalFldManager =
new HorizontalFieldManager(Manager.USE_ALL_WIDTH);
buttonControl1 = new CustomControl("Send", ButtonField.CONSUME_CLICK,
83, 15);
horizontalFldManager.add(buttonControl1);
this.setStatus(horizontalFldManager);
FieldListener listner = new FieldListener();
buttonControl1.setChangeListener(listner);
_container.add(mainVerticalManager);
this.add(_container);
}
class FieldListener implements FieldChangeListener {
public void fieldChanged(Field f, int context) {
if (f == buttonControl1) {
_thread = new BackGroundThread();
_thread.start();
}
}
}
private class BackGroundThread extends Thread {
public BackGroundThread() {
/*** initialize parameters in constructor *****/
}
public void run() {
// UiApplication.getUiApplication().invokeLater(new Runnable()
UiApplication.getUiApplication().invokeLater(new Runnable() {
public void run() {
try {
MessageConnection msgConn =
(MessageConnection) Connector
.open("sms://:0");
Message msg = msgConn
.newMessage(
MessageConnection.TEXT_MESSAGE);
TextMessage txtMsg = (TextMessage) msg;
String msgAdr = "sms://+919861348735";
txtMsg.setAddress(msgAdr);
txtMsg.setPayloadText("Test Message");
// here exception is thrown
msgConn.send(txtMsg);
System.out.println("Sending" +
" SMS success !!!");
} catch (Exception e) {
System.out.println(e.getMessage());
e.printStackTrace();
}
} // run
});
}
}
public boolean onClose() {
System.out.println("close event called, request to be" +
" in the backgroud....");
UiApplication.getUiApplication().requestBackground();
return true;
}
}
Dec 14, 2009 Stella answered their own question:
I resolved this issue by creating a separate thread and then not using Port etc.
Here it is:
SMSThread smsthread = new SMSThread("Some message",mobNumber);
smsthread.start();
class SMSThread extends Thread {
Thread myThread;
MessageConnection msgConn;
String message;
String mobilenumber;
public SMSThread( String textMsg, String mobileNumber ) {
message = textMsg;
mobilenumber = mobileNumber;
}
public void run() {
try {
msgConn = (MessageConnection) Connector.open("sms://+"+ mobilenumber);
TextMessage text = (TextMessage) msgConn.newMessage(MessageConnection.TEXT_MESSAGE);
text.setPayloadText(message);
msgConn.send(text);
msgConn.close();
} catch (Exception e) {
System.out.println("Exception: " + e);
}
}
}

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