Fixing the AutoCloseable interface of Java

Java 7 introduced the AutoCloseable interface, which is roughly equivalent to the IDisposable interface of C#, to be used in synergy with the new try-with-resources statement, which is equivalent to the using-disposable construct of C#.

The problem with Java's AutoCloseable interface is that its close() method is declared to throw a checked exception: void close() throws Exception. This is a problem if you are one of the many programmers who prefer unchecked exceptions over checked ones, because it forces you to deal with checked exceptions every time you write a try-with-resources statement, despite the fact that none of your classes ever throw any checked exceptions on close().  Simply declaring that your class implements AutoCloseable forces checked exceptions upon you.

Luckily, there is a fix for this.  Here it is:
public interface AutoCloseable2 extends AutoCloseable
    void close();
There, I fixed it for you.

By declaring a new interface which redefines the close() method as not throwing any checked exceptions, the problem goes away.


I just looked at the Oracle documentation for the AutoCloseable interface and found out that this had already been anticipated:

"[...] subclasses of the AutoCloseable interface can override this behavior of the close method to throw specialized exceptions, such as IOException, or no exception at all."