From Effective Java 2/e by Joshua Bloch
Checked exceptions force the programmer to deal with exceptional conditions, greatly enhancing reliability.
If the programmer using the API can do no better, an unchecked exception would be more appropriate
} catch(TheCheckedException e) {
throw new AssertionError(); // Can't happen!
}
} catch(TheCheckedException e) {
e.printStackTrace(); // Oh well, we lose.
System.exit(1);
}
One technique for turning a checked exception into an unchecked exception is to break the method that throws the exception into two methods, the first of which returns a boolean that indicates whether the exception would be thrown
// Invocation with checked exception
try {
obj.action(args);
} catch(TheCheckedException e) {
// Handle exceptional condition
...
}
// Invocation with state-testing method and unchecked exception
if (obj.actionPermitted(args)) {
obj.action(args);
} else {
// Handle exceptional condition
...
}
In cases where the programmer knows the call will succeed or is content to let the thread terminate if the call fails,the refactoring also allows this simple calling sequence
obj.action(args);