How to wrap a java.lang.Appendable into a java.io.Writer?

Question

UPDATE2: My own version of the adapter class, that only calls instanceof in the constructor and uses a (Java 1.5) delta in the flush() and cl

Answer 1

You can accept any Appendable and then check if it is a Writer through instanceof. Then do a downcast and call that function that accepts only Writer.

example:

public void myMethod(Appendable app) throws InvalidAppendableException {

   if (app instanceof Writer) {
      someObj.thatMethod((Writer) app);
   } else {
      throw new InvalidAppendableException();
   }
}