java - How to convert a Byte Array to an Int Array

Question

I am reading a file by using:

int len = (int)(new File(args[0]).length());
    FileInputStream fis =
        new FileInputStream(args[0]);
    byte buf[] = new byte[len];
    fis.read(buf);

As I found here. Is it possible to convert byte array buf to an Int Array ? Is converting the Byte Array to Int Array will take significantly more space ?

Edit: my file contains millions of ints like,

100000000 200000000 ..... (written using normal int file wirte). I read it to byte buffer. Now I want to wrap it into IntBuffer array. How to do that ? I dont want to convert each byte to int.

Answer 1

You've said in the comments that you want four bytes from the input array to correspond to one integer on the output array, so that works out nicely.

Depends on whether you expect the bytes to be in big-endian or little-endian order, but...

 IntBuffer intBuf =
   ByteBuffer.wrap(byteArray)
     .order(ByteOrder.BIG_ENDIAN)
     .asIntBuffer();
 int[] array = new int[intBuf.remaining()];
 intBuf.get(array);

Done, in three lines.