Re: svn commit: r557089 - in /openjpa/trunk: openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/kernel/ openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/schema/ openjpa-jdbc/src/main/resources/org/apache/openjpa/jdbc/kernel/ openjpa-lib/src/main/ja

[Craig L Russell]

It would not surprise me that IBM JDK was internally "interning" Integer instances much like String instances are interned, to reduce the number of instances of Integer and thereby improve garbage collection and instance count.

Craig

On Jul 29, 2007, at 10:35 PM, Marc Prud'hommeaux wrote:

But our code should not be using == instead of equals. The identity of an Integer should never be assumed. Best practice even if not mandated by the VM spec.

The problem is that the IBM JDK seems to want to create (copy) new Integer objects when used as keys to the HashMap.put(k,v) method. Any other key types are just used as is (no copy). But, Integer types as keys are copied

into new Integer objects.

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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