Assertion in Java is a very useful testing tool.A java developer can add more and more tests in code while developing the application.Assertion use as a safeguard to your java code.In development environment we rely on the debugging and inspect the variables when it hits the break-point.If you are using Eclipse as your development IDE , you have to enable the AssertionError exception to hit the breakpoint on the error in case an assertion fails.This post talk about setting the break point at Assertion fail.