Keep Looping until inputs are available in java

Question

If I don't know the input size already, what is the the way to keep iterating in a loop until it is available, in JAVA. In C++ it can be done as following.

int main(){
    int val;
    while(cin >> val){
           //do stuff
    } 
}

What is the way to do similar thing(as above) in java

Thanks in Advance. Shantanu

Answer 1

You should try the following thing.

    long val;
    Scanner sc = new Scanner(System.in).useDelimiter("\n");
    while (sc.hasNext()) {
        String temp = sc.next().trim();

        val = Long.parseLong(temp);
        // do stuff
    }

Answer 2

One way is to use Scanner.

long val;
Scanner sc=new Scanner(System.in);
while (sc.hasNextLong() ) {
    val = sc.nextLong();
    // do stuff
}

This is equivalent to the cpp code you provided. But not exactly what you asked for. It will loop as long as there are legal inputs in the read string.