what a difference do I make when I use BufferedInputStream to get the user input? java

Question

what is the difference between the codes below?

//case01

Scanner sc=new Scanner(new BufferedInputStream(System.in));
while(sc.hasNext())
    {
        System.out.println("输出："+sc.next());
    }

//case02

Scanner sc=new Scanner(System.in);
while(sc.hasNext())
{
    System.out.println("输出："+sc.next());
}

Possible duplicate of [Scanner vs. BufferedReader](http://stackoverflow.com/questions/2231369/scanner-vs-bufferedreader) — Naman, Mar 05 '17 at 07:00

score 0 · Answer 1 · answered Mar 05 '17 at 07:03

0

BufferedInputStream uses a buffer. You can say that it's mainly used for optimizing.

answered Mar 05 '17 at 07:03

Kavya K

11
1
4

score 0 · Answer 2 · answered Mar 05 '17 at 07:10

A BufferedInputStream provides the most value when it is used to wrapper a stream that would incur overhead for each byte fetched, since it prefetches bytes a block at a time. For example when fetching from a hard drive, or even fetching from a socket (since it limits the overhead of calling the operating system for each and every byte read).

However, System.in is typically hooked to the keyboard. So that's a situation where there is little to no benefit to be gained by buffering. Another example would be if a stream was byte array based (such as a ByteArrayInputStream). No real benefit in either case.

what a difference do I make when I use BufferedInputStream to get the user input? java

2 Answers2