Scanner tokens() in Java

tokens(): This method is available in java.util.Scanner class of Java.

Syntax:

Stream<String> java.util.Scanner.tokens()

This method returns a stream of delimiter-separated tokens from this scanner.

Parameters: NA

Returns: a sequential stream of token strings.

Throws:

IllegalStateException - if this scanner is closed.

Approach 1: When no exception

Java

import java.util.Scanner;

public class Scannertokens {
    public static void main(String[] args) {

        String source = "Hello World";
        Scanner scanner = new Scanner(source);

        System.out.println(scanner.tokens().count());
        scanner.close();
    }
}

Output:

2

Approach 2: IllegalStateException 

Java

import java.util.Scanner;

public class Scannertokens {
    public static void main(String[] args) {

        String source = "Hello World";
        Scanner scanner = new Scanner(source);

        scanner.close();
        System.out.println(scanner.tokens().count());

    }
}

Output:

Exception in thread "main" java.lang.IllegalStateException: Scanner closed
	at java.base/java.util.Scanner.ensureOpen(Scanner.java:1150)
	at java.base/java.util.Scanner.tokens(Scanner.java:2829)