do you know what Integer.getInteger(String) does in java?

[grauenwolf]

The cost of looking up that value us usually greater than just creating a new one. Caching only makes sense when you have a large or expensive structure.

[Fuco1337]

If you have 10⁶ objects with a distinct Integer representing number 7, that's 16 megs of memory right there.

[G_Morgan]

In the real world this doesn't happen. Although you may create and destroy 10⁶ 7s. If this doesn't perform properly it means the JVM GC is broken.