The hasNextLine() method of java.util.Scanner class returns true if there is another line in the input of this scanner. This method may block while waiting for input. The scanner does not advance past any input.
Syntax:
public boolean hasNextLine()
Parameters: The function does not accepts any parameter.
Return Value: This function returns true if and only if this scanner has another line of input
Exceptions: The function throws IllegalStateException if this scanner is closed.
Below programs illustrate the above function:
Program 1:
// Java program to illustrate the// hasNextLine() method of Scanner class in Java// without parameter  import java.util.*;  public class GFG1 {    public static void main(String[] argv)        throws Exception    {          String s = "gfg 2 geeks!";          // new scanner with the        // specified String Object        Scanner scanner = new Scanner(s);          // use US locale to interpret Lines in a string        scanner.useLocale(Locale.US);          // iterate till end        while (scanner.hasNextLine()) {              // print what is scanned            System.out.println(scanner.nextLine());        }          // close the scanner        scanner.close();    }} |
Output:
gfg 2 geeks!
Program 2: Program to demonstrate exception
// Java program to illustrate the// hasNextLine() method of Scanner class in Java// without parameter  import java.util.*;  public class GFG1 {    public static void main(String[] argv)        throws Exception    {        try {              String s = "gfg 2 geeks!";              // new scanner with the            // specified String Object            Scanner scanner = new Scanner(s);              // use US locale to interpret Lines in a string            scanner.useLocale(Locale.US);              scanner.close();              // iterate till end            while (scanner.hasNextLine()) {                  // print what is scanned                System.out.println(scanner.nextLine());            }              // close the scanner            scanner.close();        }        catch (IllegalStateException e) {            System.out.println("Exception is: " + e);        }    }} |
Output:
Exception is: java.lang.IllegalStateException: Scanner closed
Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#hasNextLine()
