I decide love you,the time is forever!

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!!! Permanent Generation Heap

This segment of the heap is used to store instances of {{Class}} and {{Method}} objects and their related meta data. Applications that perform a lot of dynamic classloading or dynamic class generation can quickly fill up this segment of the heap.

!! Resizing Permanent Generation

Sun JVMs allow you to resize the different generations of the heap, including the permanent generation.
On Sun JVM (1.3.1 and above) you can configure the initial permanent generation size and the maximum permanent generation size.

To set a new initial size on Sun JVM use the {{-XX:PermSize=64m}} option when starting the virtual machine. To set the maximum permanent generation size use {{-XX:MaxPermSize=128m}} option. If you set the initial size and maximum size to equal values you may be able to avoid some full garbage collections that may occur if/when the permanent generation needs to be resized.

Some of the default values for Sun JVMs are listed below.

|| JDK 1.3.1_06 || Initial Size || Maximum Size
| Client JVM     | 1MB           |  32MB
| Server JVM     | 1MB           |  64MB

|| JDK 1.4.1_01 || Initial Size || Maximum Size
| Client JVM     | 4MB           |  64MB
| Server JVM     | 4MB           |  64MB

|| JDK 1.4.2 || Initial Size || Maximum Size
| Client JVM     | 4MB           |  64MB
| Server JVM     | 16MB          |  64MB