Thread: Help Please

You could write a loop to access the elements vs having the elements individually coded.
Have the loop variable index the first dimension of the array.

Your post wasn't anything useful. If you need to copy the console:
To copy the contents of the command prompt window:
Click on Icon in upper left corner
Select Edit
Select 'Select All' - The selection will show
Click in upper left again
Select Edit and click 'Copy'

Paste here.

[Java] import java.awt.*; import java.awt.event.*; import javax.swing.*; import java - Pastebin.com

there is no compile errors

What is the problem then? Can you explain?

Please post any code you are asking questions here on the forum.

Your code has very few comments describing its logic. It will take a long time to figure out what you are trying to do.
Have you tried debugging it by adding lots of println statements to show the values of variables as they are changing. You should be able to look at the output and see where the program is NOT doing what you want it to do by seeing how the variables are being set and changed.
That is exactly how I will attempt to find the logic problem.

yeah i had a look through the logic the for loop breaks the while as each thread needs to be running in the while at all times, the for loop runs through 1 2 3 individualy shutting off the other threads, so all threads need to be running at the same time with no break in there like

while(true)
{


ovl [0] [0]+=dx;
ovl [0] [1]+=dy;



if(ovl [0] [0]-rad<0)// this checks to see if there is a horsontal collision
{
dx=-dx; // this reverses the ball away from the wall
ovl [0] [0]=rad;


}else if(ovl [0] [0]+rad>canvas_width)
{
dx=-dx;
ovl [0] [0]=canvas_width-rad;

}



if(ovl [0] [1]-rad<0)// this is the same as above but for the verttical collision
{
dy=-dy; // this reverses the ball away from the wall
ovl [0] [1]=rad;

} else if(ovl [0] [1]+rad>canvas_height)
{
dy=-dy;
ovl [0] [1]=canvas_height-rad;

}


repaint();

works perfectley but for one instance
so in order to fix it
ovl [0] [0]
ovl [0] [1]
needs to represent all items in the array at the same time
but i am not sure how to do it

ovl [0] [0]
ovl [0] [1]
needs to represent all items in the array at the same time

Sorry, I don't understand what that means.

So far I have found two problems by adding printlns and looking at the output.
How are you doing?

array line No in array collum
ovl [0] [0] = X cordinates

ovl [1] [0] = Y cordinates


i have been looking at the program testing it but i can't find any errors i dont know if its because i have been doing it for a while
what problems did you find?

Post your printed output and I point out where the problems are.
Or I'll tell you where you should add more print outs to see the problem.

here is what i got:

start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
start while dx-1
start while dy-1
4th if dy1
4th if ovl20
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1
start while dx-1
start while dy1

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>

that without the for loop

Pretty boring. When posting long repeating group, use ... in the middle.
You print outs don't show a lot of things about your program.
One thing they do show is that there is only one delta value. That's fine for one ball, but what if you have more than one ball and they are moving in different directions?

When is a new RunnableThread created?
When is that class's run method called?
System.out.println("run for " + Thread.currentThread().getName());


How is each ball being moved?
System.out.println("moving ball=" + i + ", x=" + ballData[i][0] + ", y=" + ballData[i][1]);

What is the data for a newly created ball:
System.out.println("new ball= " + java.util.Arrays.toString(ballData[nbrOfBalls]));


I need descriptive names for variables so I changed these:

private final int MaxBallData =50;
private int [][] ballData = new int [MaxBallData][4]; // What are the 4 dims used for???
private int nbrOfBalls =0;

a new runnable thread is created when the user clickes
the run method is called when a thread starts

i found that it runs thread1 then Thread - 3 which i presume is the sleep time it dose that 4 times one for each statment the it goes back to thread1

the ball moves between 20 and 21 on the x axis and random on the y which is strange i admit

and there is no data for a new ball this is because a new ball is not enter into the while loop

i am not sure about the dims, i just know the program dose not work without them.

i am sorry to keep you looking over this thread, i have not been programing java long i am in my second year at uni and arrays are not my strong point,

a new runnable thread is created when the user clickes
the run method is called when a thread starts

What is printed out by the printlns you put in the run method?
Are the print outs what you expected?

yes apart from when the new ball is added it is as tho it never go created

public void run()
{
 
      System.out.println("run for " + Thread.currentThread().getName());  //<<<<<
 
 
while(true)
{

Add this println to your code as shown above and execute it.
Look at what is printed out.

this is the print outs i got:
X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>javac *.java

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>java Bouncing_Ball
run for thread1
run for Thread-3
run for thread2
run for Thread-4
run for thread3
run for Thread-5
X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>

it runs the threads ok but the Thread-3 4 5 is abit strange i dont get why it is adding sleep time

run for Thread-3 <<<<<<<<<<<<<
moving ball=0, x=551, y=580
new ball= [0, 0, 0, 0]
run for Thread-3 <<<<<<<<<<<<<
moving ball=0, x=780, y=350
new ball= [0, 0, 0, 0]
run for thread1 <<<<<<<< New one
moving ball=0, x=449, y=20
new ball= [0, 0, 0, 0]
run for thread1 <<<<<<<<< called again???

Should run be called twice every time a new ball is added?
How many threads are supposed to be running for a ball?

Run the test and only add one ball. How many threads are shown by the print out?

no the run method should only be run once as it should continue to run
1 thread per ball should be created

i get

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>javac *.java

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>java Bouncing_Ball
run for thread1
run for Thread-3

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>

1 thread per print

If you only started one ball by clicking one time with the mouse, then why is the run method called two times? Do you wonder why you got two lines printed out?
It looks like you are creating and starting two threads.

yes that is abit strange, but how can that happen it must be because when
public RunnableThread(String s)
{
ball = new Thread(this,s);
//ball.start();


i am starting the ball here when i run it with this commented out there is only one print out


X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>javac *.java

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>java Bouncing_Ball
run for Thread-3

X:\Desktop\Programing Resit#\tests\bb2\test 2\test3>

Yes that looks right. Also you could get rid of the creation of the thread: ball = new Thread...
The Thread was created and started in another place in your code.

yeah that was careless of me to have put that there so now only the threads i need are created, but i still can't get to grips with why the out put is
messed when the for loop is in place