File Streaming in Java

Question

I\'m currently developing 3D graphics application using JOGL (Java OpenGL binding). In brief, I have a huge landscape binary file. Due to its size, I have t

Answer 1

Have you noticed that if you run a program, then close it, then run it again it starts up much faster the second time? This happens because the OS has cached the parts of the files that were accessed in the first run, and doesn't need to access the disk for them. Memory mapping a file essentially allows a program access to these buffers, thus minimizing copies made when reading it. Note that memory mapping a file does not cause it to be read whole into memory; the bits and pieces that you read are read from disk on-demand. If the OS determines that there is low memory, it may decide to free up some parts of the mapped file from memory, and leave them on disk.

Edit: What you want is FileInputStream.getChannel().map(), then adapt that to an InputStream, then connect that to the DataInputStream.