Why Validate Emails?

Validation ensures that the data entered by a user follows the correct format (e.g., user@domain.com). This prevents database errors and ensures your application can actually send emails to its users.

The Regex Pattern

In Java, we use Regular Expressions to define the "rules" for a valid email. Here is a simple but effective pattern:

The Java Code

We use the java.util.regex package, specifically the Pattern and Matcher classes.

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Scanner;

public class EmailValidator {
// The Regex Pattern
private static final String REGEX = "^[A-Za-z0-9+_.-]+@(.+)$";

<span class="token-keyword">public static void</span> main(String[] args) {
    Scanner sc = <span class="token-keyword">new</span> Scanner(System.in);
    System.out.print(<span class="token-string">"Enter your email: "</span>);
    String email = sc.nextLine();

    Pattern pattern = Pattern.compile(REGEX);
    Matcher matcher = pattern.matcher(email);

    <span class="token-keyword">if</span> (matcher.matches()) {
        System.out.println(<span class="token-string">"✅ Valid Email Address!"</span>);
    } <span class="token-keyword">else</span> {
        System.out.println(<span class="token-string">"❌ Invalid Email Address!"</span>);
    }
}
}

Key Takeaways

• 1

  Pattern.compile(): Compiles the regex string into a searchable pattern.

• 2

  matcher.matches(): Returns true if the entire input matches the pattern.