Hi guys,
I want to develop a billiards game in java,I want to know how can detect collision(ball 2 ball) & take certain actions on that?
Thank you

Collisions between circles of identical size on a 2d plane are fairly simple. If the centers of any two given circles are less than their diameter apart, they're in contact.

You can use simple trig to calculate the distance between the circles and the plane for the reflected angle that the balls will take after collision.

Adding spin might be interesting though.

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10 PRINT "Bad Monkey ";
20 GOTO 10

Depending on how comfortable you are with Java and whether you want to do the physics calculations yourself, you could use JBox2D to make a nice billiard ball simulation. I've been using it recently and have found it works very well. The documentation is somewhat poor though. Your main resources would be:

The Box2D manual for C++ - first port of call for all functions and usage scenarios.
The JBox2D library download - look inside the src folder for the testbed code, this will be your reference for pretty much everything.
The JBox2D testbed running online as a Java applet - fun to play with

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