How to Check String is Alphanumeric in Java

You can check string is alphanumeric in Java using matches() technique for Matcher class. The Matcher class is given by java.util.regex bundle.

Beneath I have shared a basic Java program in which I have taken a string and I am checking it using matches() strategy.

Program

java.util.regex.*;
 
class AlphanumericExample
{
	public static void main(String...s)
	{
		String s1="adA12", s2="jh@l";
		System.out.println(s1.matches("[a-zA-Z0-9]+"));
		System.out.println(s2.matches("[a-zA-Z0-9]+"));
	}
}

Output