JavaFX 2.0 :: How To Recover From Too Many Touch Points Reported Exceptions
Sep 17, 2014
I'm trying to stress test JavaFX and I'm on Window 8.1 using 1.8.0_20-b26. I have an application that has many objects on the scene with animation timers and overall it purposefully runs very slow. I have listeners on the root AnchorPane for touch input and if I generate many touch point events after a few minutes I get "Too many touch points reported" exceptions (posted below) and the app of course no longer responds to touch input. Is it possible to catch the exception and then reset the scene touch input so it goes back to normal without restarting the application? If it lost any current touch input that's fine.
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: Too many touch points reported
at javafx.scene.Scene$ScenePeerListener.touchEventNext(Scene.java:2686)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleNextTouchEvent$346(GlassViewEventHandler.java:1090)
I'm trying to implement a two finger gesture to move a control for a touch screen. However simply touching the screen with two fingers will generate several events that jump all over the place. This here is the code:
Two finger move pressed First layout: 100.0, 100.0 Move by 94.0, 209.0 event set=4 Move by 1.0, 0.0 event set=5 Move by 95.0, 208.0 event set=6 Move by 1.0, 1.0 event set=8 Move by 96.0, 208.0 event set=11 Move by 219.0, 147.0 event set=11 Move by -121.0, 61.0 event set=13
I know that there is the possibility that I get multiple events with the same event set id. However this is not always the case. I would have expected to get one for each of the finger in the gesture. Why is that? As I understand the difference between changing the layout coordinates and the transformation is, that with the transformation coordinates, the bounds in parent changes, but not the bounds itself.
I'm not entirely clear on what effect this has, especially as I will also have the zoom and rotate gesture on the component. Which one is the better choice to change?To my understanding the coordinates of the touchpoint are relative to the parent component. In this case the layout coordinates of the rectangle. This would mean that I have to calculate the delta of the touch point in the onTouchMoved to the touch point of onTouchPressed.
This would get me the vector the rectangle moved.In the above example I use the main touch point of the two touchpoints of the event. As I understand it this should always be the same one. The correct way would be to calculate the geometric mean of the two points and use that, but that has the same effect. Simplifying the above example to one touch point only shows the same jumping behavior.
We are doing a visualisation tool for point cloud research project. We use 3d sphere to represent each single point and when we have large number of points to display (~40,000), the rotation becomes very lagging.
What we have tried:
set JVM flag -Djavafx.animation.fullspeed=true, this worked a bit, but not significant.set JVM flag -Djavafx.autoproxy.disable=true, this did not work.
set Cache to true and CacheHint to Cache.SPEED, this did not make much difference.create another thread to do the rotation, and sync back after calculation, this did not work neither.
This is what he wants: He wants us to prompt the user to input x values and y values (that will be entered into an array when clicking one of the two buttons (this one will say: Add point)). When they click the second button (draw lines), it should take all the points and draw a line that connects all the points together using a method that we write. In the method we have to call the paint method up which the lines will be drawn. The lines drawn should be touching every point added. It shouldn't have parameters. It will also use Graphics painter = getGraphics(); We can't use frames either.
I have everything up until the method understood.
How to write a method that will draw a line from points inputted that is called up in the action listener when the second button (draw lines) is pressed.
Here I would like to collect automatically in a file ( txt) the characters displayed on the screen. I'm working on a system that the database is remote. To receive information, there is a terminal by which sends commands. The feedback is displayed only on the screen and you can only print. This is actually a terminal black screen, white character, such as command line "DOS" . The software can not export , or access to the database or other means of information retrieval .
I explored the track of the OCR . But the result produced is not consistent with the captured picture. How can I do this? I have no other tracks ....
Haven't used java in a long long time and firstly need to know if its possible to build an app to replicate my ipad touch so that I can loop it between two different points on the screen. Friend recommended I got netbeans to get me started but wanted to ensure its possible before I get started.
And we have a class that draws a rectangle of 10 pixel height and 10 pixel width at 0,0 coordinates.
And we want to move with the arrows the rectangle but not to go off the frame.
The question is:
How can I do that if I draw another rectangle, it knows where is the other object and they not collapse. And so on, they move, but not collapse, just touch and stop.
I don't know how to write a code to pong ball, when it touch red block.
public class bounc2 extends JPanel implements ActionListener,KeyListener{ double x = 0,y=0,velX=3,velY=3; double x2 = 5,y2=145,velX2=0,velY2=0; double x3= 473,y3=145,velX3=0,velY3=0; Timer t = new Timer(5,this); public bounc2(){ setBackground(Color.GREEN);
I want to make a touchable program to install on my costumer information server that my client can search and register via my local database, how can i do this????
I am just learning how to throw exceptions, and I'm stuck on the last part,
Here is where I created the exception that receives a string consisting of ID and wage.
public class EmployeeException extends Exception { public EmployeeException(String Employee) { super(Employee); } }
Here is where I created the Employee class with the two fields. I also believe I am throwing the exception if the hourly wage is < $6 or > $50.
public class Employee { int idNum; double hourlyWage; public void Employee(int empID, double empWage) throws EmployeeException { idNum = empID; hourlyWage = empWage;
[Code]...
Now, I need to write an application with three employees and display a message when an employee is successfully created or not. This is what I have so far... I'm trying to get it to work with one employee, and then I can easily go back and add two more.
import javax.swing.*; public class ThrowEmployee { public static void main (String[] args) { try { Employee one = new Employee(542, 15.20); }
[Code
The current compile error that I'm receiving is: ThrowEmployee.java:12: error: constructor Employee in class Employee cannot be applied to given types;
Employee one = new Employee(542, 15.20); ^ required: no arguments found: int,double reason: actual and formal argument lists differ in length 1 error
I have public void Employee(int empID, double empWage) in my Employee class, so why is it saying that no arguments are required? Not sure if I'm missing a step with throwing exceptions, because this error has always been a simple fix when I've come across it in the past?!?
In my EJB modules, to prevent that any JPA exception is ever thrown, I check the condition that would cause the exception beforehand. For example, the exception javax.persistence.EntityExistsException is never thrown because, before persisting the entity, I check if such primary key already exists in the DB. Is it the right way to do this?
Another approach is too allow the JPA exceptions to be thrown and catch them in a try-catch block, and then throw my custom exception from the "catch" block. However it requires to call EntityManager.flush () at the end of the "try" block. Otherwise the exception throw could be deferred and never be caught by my block.
There are times that my methods need to report the caller about many kinds of errors, represented as checked exceptions. This makes my methods look like very convoluted. It happens mostly when I work with stateless EJBs and databases. Sometimes I end throwing even 8 different exceptions! Are they too many?
Many of them inherit from common exceptions, so I've been tempted to throw the parent classes. But I've quickly discarded that option because I've read that it's a bad practice, since a method may throw only a subset of the children of that parent class, not all.
Finally, I've studied these possibilities:
1. Throwing the parent class (mentioned above). 2. Throwing a common exception with an error ID or code as message. 3. Throwing a common exception with an enum as member, as if it were an ID or code (safer than the #2).
All them show the same defect that the #1. However it's more a conceptual problem than a technical one, because my callers always use the same mechanism to treat every "specialization" of the same exception, without worrying about if the method really can return it or not.
I'm writing a program that accepts three doubles from the user, and performs calculations on them. I want to be able to handle input mismatch exceptions on each individually (i.e., if the user enters a double for the first, then a letter for the second, I'd like to be able to keep the value entered for the first, and only require that the user try again with the second, then the third, etc.)... I tried putting each input instance into its own try/catch blocks, but it always goes back to #1 when an invalid input is entered. Right now, I have all three in one try/catch:
I'm wondering about the use of exceptions to handle errors that might occur during file I/O when the I/O is done by a method implementing an interface's method. The idea is for the interface to provide a uniform way for application code to read (and write, though I'm not addressing that in this post) a document from a file, given a File object that specifies the on-disk location of the document. The "document" can be an instance of any class the application programmer wants it to be, provided that it can be created from a file stored on disk. Here's the interface definition:
public interface DocumentRamrod<T> { public T openDocumentFile(File file) throws FileNotFoundException; }
A simple implementation, when T is a class that just holds a String, might look like this (Please overlook the fact that there is no call to the BufferedReader's close method, as it's not needed for this example.):
public class MyRamrod implements DocumentRamrod<OneLineOfText> { public OneLineOfText openDocumentFile(File file) throws FileNotFoundException { return new OneLineOfText(new BufferedReader(new FileReader(file)).readLine()); } }
But, that one line where the file is read (Line 5) might generate an IOException.To cope with it, I could add a try-catch to the implementation like this:
public class MyRamrod implements DocumentRamrod<OneLineOfText> { public OneLineOfText openDocumentFile(File file) throws FileNotFoundException { try { return new OneLineOfText(new BufferedReader(new FileReader(file)).readLine()); } catch (IOException ex) { Logger.getLogger(MyRamrod.class.getName()).log(Level.SEVERE, null, ex); } } }
Or, I could add that to the list of exceptions defined for the method in the interface, like this:
public interface DocumentRamrod<T> { public T openDocumentFile(File file) throws FileNotFoundException, IOException }
But that's where I'm getting nervous, as it makes me realize that, with an infinite number of possible implementations of openDocumentFile, I can't predict what all the exceptions thrown might be.should I have openDocumentFile simply throw Exception, and let the application programmer sort out which one(s) might actually be thrown, should I keep listing them as it become clear which ones are likely to be thrown, or should I not have openDocumentFile throw any exceptions and let the application programmer deal with it in the implementation of openDocumentFile (with try-catch blocks, etc.)? In Good Old C, I'd have passed back a null to indicate some general failure, with the various callers up the call-stack having to either deal with it or pass that back themselves (until some routine up the stack finally did deal with it), but that seems like an approach the whole exception mechanism was designed to avoid.
I'm thinking the right choice is to have openDocumentFile throw Exception, and let the application programmers decide which subclasses of Exception they really want to deal with. But I have learned to be humble about the things I think, where Java is concerned,
I am having some difficulties grasping the concept of throwing your own exceptions. How do I get this to repeatedly ask the user to enter a valid value for hours. Also i am having difficulties in the method with using the throw new InvalidHrExcep("That value is invalid"); i cannot get this to work.
public class exceptionProgram { static Scanner console = new Scanner(System.in); public static void main(String[] args) throws InvalidHrExcep { int day=0; int month = 0; int year=0; int hours=0; int minutes=0; int seconds=0;
class A { final Object b; public A(C c) { try { b = c.someMethodThatMayThrowSomeException(); } catch (SomeException e) { b = null; // This line results in compiler error: "variable b might already have been assigned" } } // take away b=null line and you get "variable b might not have been initialized" on this line }
Why? How could 'b' be assigned if the exception was thrown?
currently we can able to monitor all calls given to this class but whenever any exception thrown in this class hierarchy we are not able to track it on exceptions.jsp of JAMON
I am designing/coding a blackjack GUI program and I'm trying to add function to my JButtons. Problem is, I now have 2 NullPointerExceptions.
public class GameConsole { Player user; Player dealer; Deck playingDeck; ValidateInput validate = new ValidateInput();
[Code] .....
I am trying to do. I am getting the following exception/stack trace at line 14 in userTurn()
Exception in thread "main" java.lang.NullPointerException at blackjackControls.GameConsole.userTurn(GameConsole.java:163) at blackjackControls.GameConsole.gamePlay(GameConsole.java:87) at blackjackControls.Main.main(Main.java:7)
and then the program continues and after I click the button I get :
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException at blackjackControls.GameConsole.userTurn(GameConsole.java:163) at blackjackControls.ResultPanel$1.actionPerformed(ResultPanel.java:34) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028) //and then about 30 more "at" lines
Why am I getting these exceptions and how do I fix it?
I am having some serious difficulty getting my project off the ground. I have the following code:
FileInputStream file = new FileInputStream(new File("src/retestchecker/test_sheet.xlsx")); //Get the workbook instance for XLS file XSSFWorkbook workbook = new XSSFWorkbook(file); //Get first sheet from the workbook XSSFSheet sheet = workbook.getSheetAt(0); Row row = sheet.getRow(0); Cell x = row.getCell(3); System.out.println(x);
Everything is properly imported, etc etc.. But I am getting this error and I am not sure what it means:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/xmlbeans/XmlException at retestchecker.RetestChecker.main(RetestChecker.java:23) Caused by: java.lang.ClassNotFoundException: org.apache.xmlbeans.XmlException at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
[Code] .....
Java Result: 1
I am using Netbeans and the latest version of Apache POI that was released May 11, 2015.
The line 23 that the error refers to is this line:
I am planning a race simulator car and I have a problem to get the x and y coordinates from the graph (or circuit). I explain the problem better. If I for example, drawing an arc using the library DRAW2D how do I get all the points in x and y coordinates of that arc?
In one part of my small code, I want to make a sky which will have area of 200 * 200 pixels, and inside I want to have 100 randomly placed stars (I tried to make an array of 100 elements - of class "Point").Each star should have its x and y coordinate, and I don't know how to do it. I tried many things.
import java.util.Random; import java.awt.Point; public class Sky { private Point[] stars = new Point[100]; public Sky() { for(int i = 0; i< stars.length; i++){ Random r = new Random(); int u = r.nextInt(199); int v = r.nextInt(199); //x[0].setLocation(u,v); 21stars[0].x = 5;
