How do i read in a vector of integers with a space inbetween (i.e. 0 1 2 3) and make it an integer array? in java

Try the Scanner class.

If you are reading in from the keyboard, it would look like:

import ...
Scanner sc=new Scanner(System.in);
...
int i=0;
while(sc.hasNext()){
a[i]=sc.nextInt();
i++;
}

Read the Java API under Scanner for more detailed information.
http://download.oracle.com/javase/1,5.0/docs/api/java/util/Scanner.html