As mentioned by @JeroenVannevel, there really isn't a good way to do this. The best you can do is something like this:

import javax.swing.JOptionPane;

public class MailTest {
    public boolean isEmailAddress(String emailAddress) {
        return emailAddress.contains("@");
    }

    public static void main(String[] args) {
        String emailAddress = JOptionPane.showInputDialog("Enter an email address.")

        if(isEmailAddress(emailAddress)) {
            System.out.println("What a correct email!");
        }
    }
}

As, again mentioned by @JeroenVannevel, there are just too many issues to consider when trying to validate email addresses, here are just a few of those issues:

• An email address doesn't necessarily, end with a domain name, i.e, foo.bar.
• An email address can contain an IP address as a domain name, i.e, 3.3.4.2, or others.
• An email address can also have different formats as well.

In short, the only "good" way to check if an email address is valid is to ensure that it contains an @ character.

As mentioned by @JeroenVannevel, there really isn't a good way to do this. The best you can do is something like the below. Essentially, I have one function, isEmailAddress, which returns true if an @ character is found in the email address.

import javax.swing.JOptionPane;

public class MailTest {
    public boolean isEmailAddress(String emailAddress) {
        return emailAddress.contains("@");
    }

    public static void main(String[] args) {
        String emailAddress = JOptionPane.showInputDialog("Enter an email address.")

        if(isEmailAddress(emailAddress)) {
            System.out.println("What a correct email!");
        }
    }
}

As, again mentioned by @JeroenVannevel, there are just too many issues to consider when trying to validate email addresses, here are just a few of those issues:

• An email address doesn't necessarily, end with a domain name, i.e, foo.bar.
• An email address can contain an IP address as a domain name, i.e, 3.3.4.2, or others.
• An email address can also have different formats as well.

In short, the only "good" way to check if an email address is valid is to ensure that it contains an @ character.

As mentioned by @JeroenVannevel, there really isn't a good way to do this. The best you can do is something like this:

import javax.swing.JOptionPane;

public class MailTest {
    public boolean isEmailAddress(String emailAddress) {
        return emailAddress.contains("@");
    }

    public static void main(String[] args) {
        String emailAddress = JOptionPane.showInputDialog("Enter an email address.")

        if(isEmailAddress(emailAddress)) {
            System.out.println("What a correct email!");
        }
    }
}

And hope for the best.

As mentioned by @JeroenVannevel, there really isn't a good way to do this. The best you can do is something like this:

import javax.swing.JOptionPane;

public class MailTest {
    public boolean isEmailAddress(String emailAddress) {
        return emailAddress.contains("@");
    }

    public static void main(String[] args) {
        String emailAddress = JOptionPane.showInputDialog("Enter an email address.")

        if(isEmailAddress(emailAddress)) {
            System.out.println("What a correct email!");
        }
    }
}

As, again mentioned by @JeroenVannevel, there are just too many issues to consider when trying to validate email addresses, here are just a few of those issues:

• An email address doesn't necessarily, end with a domain name, i.e, foo.bar.
• An email address can contain an IP address as a domain name, i.e, 3.3.4.2, or others.
• An email address can also have different formats as well.

In short, the only "good" way to check if an email address is valid is to ensure that it contains an @ character.