Scanner findWithinHorizon(String, int) in Java

findWithinHorizon(String, int): This method is available in java.util.Scanner class of Java.

Syntax:

String java.util.Scanner.findWithinHorizon(String pattern, int horizon)

This method takes two arguments. This method attempts to find the next occurrence of a pattern constructed from the specified string, ignoring delimiters.

Parameters: Two parameters are required for this method.

pattern: a string specifying the pattern to search for.

horizon: the search horizon.

Returns: the text that matched the specified pattern.

Throws:

1. IllegalStateException - if this scanner is closed.

2. IllegalArgumentException - if the horizon is negative

Approach 1: When no exception

Java

import java.util.Scanner;

public class ScannerfindWithinHorizon2 {
    public static void main(String[] args) {

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

        String pattern = "[a-z]";
        int horizon = 1;

        System.out.println(scanner.findWithinHorizon(pattern,
                                                     horizon));
        scanner.close();
    }
}

Output:

null

Approach 2: IllegalStateException

Java

import java.util.Scanner;

public class ScannerfindWithinHorizon2 {
    public static void main(String[] args) {

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

        String pattern = "[a-z]";
        int horizon = 1;
        scanner.close();
        System.out.println(scanner.findWithinHorizon(pattern,
                                                    horizon));

    }
}

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.findWithinHorizon(Scanner.java:1781)
	at java.base/java.util.Scanner.findWithinHorizon(Scanner.java:1746)
	

Approach 3: IllegalArgumentException 

Java

import java.util.Scanner;

public class ScannerfindWithinHorizon2 {
    public static void main(String[] args) {

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

        String pattern = "[a-z]";
        int horizon = -1;

        System.out.println(scanner.findWithinHorizon(pattern,
                                                   horizon));
        scanner.close();
    }
}

Output:

Exception in thread "main" java.lang.IllegalArgumentException: horizon < 0
	at java.base/java.util.Scanner.findWithinHorizon(Scanner.java:1785)
	at java.base/java.util.Scanner.findWithinHorizon(Scanner.java:1746)