The semantics of the declare soft statement have been refined in AspectJ 5 to only soften exceptions that are not already runtime exceptions. If the exception type specified in a declare soft statement is RuntimeException or a subtype of RuntimeException then a new XLint warning will be issued:
declare soft : SomeRuntimeException : execution(* *(..));
>> "SomeRuntimeException will not be softened as it is already a RuntimeException" [XLint:runtimeExceptionNotSoftened]
This XLint message can be controlled by setting the runtimeExceptionNotSoftened XLint parameter.
If the exception type specified in a declare soft statement is a super type of RuntimeException (such as Exception for example) then any checked exception thrown at a matched join point, where the exception is an instance of the softened exception, will be softened to an org.aspectj.lang.SoftException.
public aspect SoftenExample {
declare soft : Exception : execution(* Foo.*(..));
}
class Foo {
public static void main(String[] args) {
Foo foo = new Foo();
foo.foo();
foo.bar();
}
void foo() throws Exception {
throw new Exception(); // this will be converted to a SoftException
}
void bar() throws Exception {
throw new RuntimeException(); // this will remain a RuntimeException
}
}