New to Java

Hello

I have initialise a byte buffer in my program and allocate memory to it like the following:

byte[] buffer = new byte[100]

In the middle of the program I am making this buffer null

buffer = null;

I want to know can i reuse this buffer without allocating memory to it by new. I do not want to do new everytime

Is there any other method that can make this buffer empty(Basically i want to do this only)

Please help

Thanks