Re: Alternative to System.runFinalizersOnExit()?

From:

Thomas Hawtin <usenet@tackline.plus.com>

Newsgroups:

comp.lang.java.programmer

Date:

Tue, 14 Nov 2006 17:56:03 +0000

Message-ID:

<455a02fc$0$8733$ed2619ec@ptn-nntp-reader02.plus.net>

Twisted wrote:

Thomas Hawtin wrote:

be careful you don't do anything extra after acquiring, such as wrapping
in a buffer decorator).

     // WRONG:
     final OutputStream out = new BufferedOutputStream(
         new FileOutputStream(file)
     );
     try {
         ...
         out.flush();
     } finally {
         out.close();
     }

     // STILL WRONG (and daft):
     OutputStream out = null
     try {
         out = new BufferedOutputStream(
             new FileOutputStream(file)
         );
         ...
         out.flush();
     } finally {
         if (out == null) {
             out.close();
         }
     }

What if construction of the BufferedInputStream failed due to lack of
memory, or some other reason? Leak. Therefore:

     final OutputStream rawOut = new FileOutputStream(file);
     try {
         OutputStream out = new BufferedOutputStream(rawOut);
         ...
         out.flush(); // Also important, buffered or not.
     } finally {
         rawOut.close();
     }

It's a narrow window, but it could mean the difference between dying
under load or just suffering.

Tom Hawtin