Checked and Unchecked exceptions

[subash chandar]

What is the difference between checked and unchecked exception.

How to identify whether an exception is checked or unchecked.
Is RunTimeException checked or unchecked

[Paul Sturrock]

Checked exceptions are have to be handled at compile time, unchecked exceptions need to be handled at runtime. Checked exceptions subclass java.lang.Exception, unchecked exceptions subclass java.lang.RuntimeException. Here this can be a little confusing, since RuntimeException also extends Exception. The thinking is that unchecked exceptions are supposed to be more trivial (though this is not necessarily how it works in practice).