How To Access One Thread From Another Thread
Oct 8, 2014How to access one thread from another thread?
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Swing/AWT/SWT :: What Is Event-dispatching Thread For GUIs And Why Use It Over Main Thread
Sep 20, 2014I'm currently learning about Swing but I can't get my head round this piece of the code. Here is a simplified gui (not interested in the gui part but the execution)
public class SwingDemo implements ActionListener {
SwingDemo(){
JFrame jfrm = new JFrame("Simple gui pro");
//rest of code
public static void main(String[] args) {
new SwingDemo();
}
I get the above, create a new instance of SwingDemo in the main thread which starts up the gui through the constructor. However, then the tutorial says that I should avoid doing the above but do this instead:
public class SwingDemo implements ActionListener {
SwingDemo(){
JFrame jfrm = new JFrame("Simple gui pro");
//rest of code
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() { //why do this instead?
public void run(){
new SwingDemo();
}
});
}
}
Reading, it talks about an event-dispatching thread which has completely lost me... Why not just instantiate the object directly instead of creating another thread?
Passing 2 Sub Arrays Into Sorting Thread Then To A 3rd Thread Merge
Oct 17, 2014im having an issue with the 3rd thread that are supposed to merge the two sorted sub arrays , i pass the 2 subarrays to my runnable function sortlist and they are renamed IntSortList 1 and 2 and th1.start() and th1.join() are called and it works fine, but then i have another runnable constructor that takes IntSortList 1 and 2 but it does take a runnable. below is the code in my main,
Runnable InSortlist1 = new sortList(data2p1);
Runnable InSortlist1 = new sortList(data2p1);
Thread th1 = new Thread (IntSortlist1);
Thread th2 = new Thread (IntSortlist2);
try
{
th1.start();
th1.join();
[code]....
Swing/AWT/SWT :: Invalid Thread Access - Unknown Source
Apr 23, 2014I am new to threads, This is a project about 2048 game to be more accurate, and i want this project to run in this thread that i make in main...
My main:
public class Execute {
public static void main(String[] args){
Display d = new Display();
Shell s = new Shell(d);
Model m = new Game2048Model();
View ui = new Game2048View(m.getBoardArr(),d,s);
[Code] ....
And the error is:
Exception in thread "Thread-0" org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.widgets.Display.error(Unknown Source)
at org.eclipse.swt.widgets.Display.checkDevice(Unknown Source)
at org.eclipse.swt.widgets.Display.readAndDispatch(Unknown Source)
at view.Game2048View.run(Game2048View.java:55) //problem at Run
at java.lang.Thread.run(Unknown Source)
Here is the problem....
@Override
public void run() {
while(!shell.isDisposed()){
if(!display.readAndDispatch()){
display.sleep();
}
}
display.dispose();
}
Accessing A Variable Of A Thread From Another Thread
Jul 16, 2014class A extends Thread
{
String str;
public void run( )
{
//random stuff
}
}
[Code]....
How To Delete A Thread
Nov 19, 2014Doesn't matter now, I solved it but I don't know how to delete a thread...
View Replies View RelatedAdd KeyListener To Thread
Feb 13, 2014I want to try and run a thread that starts running on start and quits after pressing a key.I cant seem to detect keypresses. ci cant seem to add code: Post denied. New posts are limited by number of URLs it may contain and checked if it doesn't contain forbidden words.
its just a code snippit without links or anything..this is a small part... but how do i add a keyListener in here that listends to a random key?The class implements KeyListener and the overrided method "keyPressed" sets the isRunning boolean to false... but the keyPressed method is never executed.
public static void main(String[] args) {
Thread thread = new Thread() {
public void run() {
while(isRunning){
System.out.println("running");
try {
sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
};
thread.start();
}
How To Start New Thread
Apr 27, 2014how to start a new thread
public class pracDraw extends JFrame {
private Color red=Color.red;
public int i;
private Color white = Color.white;
JPanel pr=new JPanel();
JTextField t=new JTextField();
[code]....
If u run it you can see that the JTextField (t1) is drawn on the panel along the line but it does so with a gray border. How do i eliminate that grey border and only draw the text field along the line and finally make the text field green after it reaches the end of line?
Paint In Thread Or Runnable
Jun 25, 2014import java.awt.Graphics;
import javax.swing.JFrame;
class node{
node(int a,node next){
this.a=a;this.next=next;
[Code] ....
The code was ran not right, I want it's result is: 1 2 3 4 5 and delay(1000) every time that it prints a number
Example: 1 (delay(1000)) 2 (delay(1000)) ....
And the paint must do that
How To Interrupt A Thread In Java
Apr 29, 2015i know how to interrupt a thread in java but somehow it is not working.
My Application looks like this
public class MyThread {
public static void main(String[] args) {
Thread testThread = new Thread(new GreatThread());
testThread.start();
[Code]....
I always read that interrupting a Thread is so much better than the .stop method but somehow the interrupt method don't work?
Looping Thread Out Of Sync
Dec 12, 2014I have a program ive been working on and it works, but the flags in the runnables seem to shift the output down 1. for instance i commented playa3. start(); to see whats going on, if i just run playa1 i got no issues, as soon as i enable playa2, i get this output:
Game continues...
Dealer places King and Queen on the table.
Game continues...
Dealer places Queen and Ace on the table.
Player one with 'Ace' places his card on the table.
Player one with 'Ace' wins the current deal.
King Queen
Game continues...
Dealer places Queen and King on the table.
Player two with 'King' places his card on the table.
Player two with 'King' wins the current deal.
Queen Ace
the second time the dealer deals, player one places his cards on the table when he was supposed to do that for the first deal which he didnt. the last line there, (king queen) is just a print statement that is referring to the dealers hand that, that iteration is responding too. below is my code, i
import java.util.*;
import java.io.*;
import java.lang.*;
public class P5
{
public static int i, count, dealerFirstCard, dealerSecondCard, player1, player2, player3;
public static String cardSet [] = {"Ace","King", "Queen"};
public static volatile boolean dealerFinished= false;
public static volatile boolean playersFinished= false;
[code]....
Method Not Called Within Thread?
Oct 23, 2014 have written a new class that contains a thread.
From within that thread I try to call a method from within the same class the contain the thread. This method is not being called. I have confirmed that that section of code is being executed in the thread.
If you look at the following code, the thread being run is called MainThread ln 114, and the method it calls that is not being executed is called onprogressTime() ln 105;
package com.example.scott.coloursquares;
import android.content.Context;
import android.graphics.BitmapFactory;
[Code]....
Accessing Keylistener From Thread
Mar 23, 2014I start my thread, it's for a real basic game I'm learning. Everything was working fine, until I got to recognizing keys. It runs, and I can close using the mouse on the close command, but the keys aren't being generated from the keyboard. I copied it to a working sample, and here are the two files.
package testkeys;
import java.awt.Canvas;
import java.awt.Dimension;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import javax.swing.JFrame;
[Code] ....
The idea was to set the return value to true if any key is pressed, thus quitting, for this short sample program. Problem, it never recognizes any keys pressed on the keyboard. New to java and threading.
Exception In Thread Main
Jan 11, 2014I am new to java and still learning. I am trying to execute the code below which compiles successfully, but getting the following error:"Exception in thread "main" java.lang.NoSuchMethodError: main"
Code:
class Dog{
int size;
String name;
String breed;
void bark(){
System.out.println("woof woof");
}
}
class DogTestDrive{
[code]....
Thread And Clock Management
Dec 19, 2014I have objects (baddies in a game) that have individual clocks/counters assigned to them (when I make an object, I fill an integer based array list with a new digit entry at a value of one) that all happens in threads. then in another thread, I am checking the whole list of clocks, to see if any are equal to a wanted value , then I am taking an action and reseting the clock at that point on the array list.
now, the problem is:even though my code says " yes, I've taken that action because the value of array position x was >= specified value and I will now reset the clock" it doesn't reset the clock. Here is what it looks like
*these are excerpts taken from a really big program, however they should stand on their own as they are individual classes
Java Code:
public class levelclock extends Thread {
public void run() {
while (Run2 == true) {
if (Run == false) {
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
[code]....
(Attached, just open up the zip and read the .txt)
Read And Process File Using Thread?
Nov 4, 2014I created a main class called X and two Y and Z classes.
Y and Z implements Runnable classes.
class X contains a static array A that can be accessed in Y and Z.
The Run () method of the class Y reads an input file and populates the vector A.
The Run () method of the Z class uses data stored into the vector A to process some data.
The objective of using threads in this problem is: as the vector A is filled in the Run () method of class Y, the Run () method of the class Z will processing the received values in the vector A.
to do this I did the following calls in the main method of class X:
ObjectY y = new Y ();
Thready thread = new Thread (objectY);
threadY.start ();
ObjectZ new Z = Z ();
Threadz thread = new Thread (objectZ);
threadZ.start ();
is that correct? I'm getting the expected results, but dont know if the code is parallelized in fact.
Threads - Object Visible To More Than One Thread
Mar 24, 2014I need a small example of an object which is visible to two different threads.
Does saying "an object is visible to two threads" mean that it's fields or methods are being used in both the threads? I am not clear about that.
Implementing A Thread-safe Queue
Jul 10, 2014I have situation where a user can request java server to send a value to an embedded device, and if the device is asleep, that value needs to be stored in a queue until the device wakes up and sends a position to java server, at which point the server checks if there is a value in the queue and if there is, it then sends that value to the device. The maximum size of the queue is 1 for now. And if the user makes continuous requests to java server, the old value is removed and the new value is added.
Initially I was looking into BlockingQueue, but the problem with that is, well, it blocks. queue.put(value) will block if queue is full, and queue.take() will block if queue is empty. I can't have something that blocks. When the device responds to server, server checks if value is in queue, if it is not then the server carries on the rest of its responsibility. Thus, I then entertained ConcurrentLinkedQueue. While queue.offer(value) and queue.poll(); allow you to add and remove values respectively from the queue without blocking, it does not allow you to set a maximum size limit of the queue. My queue must have a maximum size limit and it has to always be the newest value the user submits to the queue (where old values are removed).So this is what I came up with:
Java Code: class Unit {
private List<Integer> cmdQueue;
public Unit(){
cmdQueue = Collections.synchronizedList(new LinkedList<Integer>());
[code]....
I use Collections.synchronizedList, as I do here, do I still need to use synchronize as I did above?
Thread And Passing Exception With Two Classes
Jan 23, 2014I have two classes, where main class is simple with only main function in it. Another class extends Thread and there's couple of functions I want to execute from main class.
Problem: I try to get other.shut() to be run in main class catch() block, after I have stopped the other class's running thread (e.g. by ctrl+c).
I think I need to somehow "pass" the exception from other class to main class so it goes to the catch block?
Code for main class:
Java Code:
public class MainClass {
public static void main(String[] arguments) {
OtherClass other = new OtherClass();
try {
other.exec();
} catch (Exception e) {
other.shut();
[Code] .....
Pause And Resume Thread Using MouseClick?
Oct 30, 2014Here I want to make a simple program where a Ball keep bouncing forever, then I add a MouseClick Listener to stop and resume thread (I mean, to stop moving Ball and to resume again). The problem is I can stop the thread using wait(), But I can not resume it. Below is the code
public class TestResumePauseBall {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public synchronized void run() {
Field aField = new Field();
[code]....
At first I think that notify() must be called from another active thread. So I add a 'class Timing implements Runnable'. Then I call notifyAll() from class Timing. But still it was failed.
After wait() called on Ball's thread, the whole frame also freeze. I can not understand why this happen?
If this test success, I will add 1 one more ball and add keyboard keys as controller of ball's movement.
No Suitable Constructor Found For Thread
Nov 22, 2014I have written a class that uses a thread and i am getting wierd error message saying no suitable constructor found for Thread(Tunnel) doesn not like this line, Thread lb = new Thread (tunnel);
import java.lang.*;
public class leftBound implements Runnable {
Tunnel tunnel;
public leftBound(Tunnel tunneler) {
tunnel = tunneler;
Thread lb = new Thread(tunnel);
lb.start();
[Code] .....
works fine if i do this though
import java.lang.*;
public class leftBound implements Runnable {
Tunnel tunnel;
public leftBound(Tunnel tunnel) {
this.tunnel = tunnel;
Thread lb = new Thread(this);
lb.start();
[Code] .....
But how do i get it to compile without using "this" method.
Creating A Thread - Unexpected Output
Mar 18, 2014Java Code:
package Threads;
public class Threads1 implements Runnable {
public void run(){
System.out.println("
* * * * *
");
}
public static void main(String[] args) {
[code]...
Java Code:
new Thread(new Threads1()).start(); mh_sh_highlight_all('java');
should execute the thread associated with the run() and then the control should return to the next statement in the calling thread (the thread from which the other thread (associated with run()) was called); isn't it?
Determining When JAVA Thread Is Finished
Jul 27, 2014I have been new to JAVA programming language and have been using it for generation of a GUI (with NET BEANS).
My problem is, when i start a thread within GUI, that takes some amount of time to get finished (around 5min to 20min cpu time),
I need an a way to detect when the thread is done and accordingly some action to be taken afterwards.
I tried with isAlive, but to no avail.
Example is, I press an JButton, thread starts, when finished Jbutton get colour changed.
Each Thread Should Read Files From Different Folders
Apr 14, 2015I need to read folder structure from the excle file and need to read all the files which are available inside folder structure.folder structure like below
c:Migrate
C:MigrateMigrateFiles
...
...
..etc.
I am ble to read files which is avalibale in all the folders with single thread,i want to read those files with multiple threads,each thread shoud reads the files from different folder. here how to read.
How Interrupt Method Work In Thread
Jul 15, 2014I am following this article [URL] .....
And here is my code
public class SimpleThreads {
// Display a message, preceded by
// the name of the current thread
static void threadMessage(String message) {
String threadName =
Thread.currentThread().getName();
[Code] .....
I want to know How join() and interrupt() method is working on this program?
Instance Variable Are Not Thread Safe
Jul 10, 2014Implementation that proves that instance variables are not thread safe ....
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