Use of assertion in java with an example?

Assertions allows us to verify the correctness of an invariant in code. They should never be triggered in production codeThey can be activated at run-time by way of the -ea option on the java command, but are not turned on by default.

An example:

public Foo acquireFoo(int id) {

  Foo result = null;

  if (id > 50) {

    result = fooService.read(id);

  } else {

    result = new Foo(id);

  }

  assert result != null;

  return result;

}


Complete discussion: http://stackoverflow.com/questions/2758224/assertion-in-java