Exception transparency - lone throws (no checked exceptions)

[Peter Levart]

Hello Stephen,

Interesting proposal. You don't specify what happens if code in a method calls a method with "lone throws" but doesn't catch anything or catches only some exceptions (but not all Throwables). Does the calling method have to declare "lone throws" too?

      interface Block<T> {
          public void invoke(T element) throws;
      }

      class MyBlock implements Block<String> {
          public void invoke(String element) throws {
            new File(element).getCanonicalFile().delete();
          }
      }


void myMethod() { // ?? do we have to declare "lone throws" here? 
     try {
         MyBlock b = new MyBlock();
         b.invoke("C:\README.txt");
     } catch (SQLException ex) { // will not be thrown from MyBlock.invoke anyway...
         ...
     }
}


If not, does that mean that "sneaky" thown exceptions can be thrown by such methods?


Regards, Peter