如何验证来自JTextField的电子邮件

Question

Just like the title says, I want to display a jOptionPane if there's a missing specific character in a jTextField. Let's say that character is "@".

I tried something like this:

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {   
   String email = (String)txtEmail.getText();
   if (!email.equals(email) && email.equals("@")){
      jOptionPane1.showMessageDialog(null, "Please"); 
   }
}

However, I can't get this to work. I also tried using contains() and contentEquals() but I don't know how to use it properly so I had changed the code. Searching on Google also doesn't help because I can't find what I want. Please consider helping. BTW, I'm using netbeans.

Answer 1

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {   
    String email = txtEmail.getText();
    if (!email.contains("@")) {
        jOptionPane1.showMessageDialog(null, "Please"); 
    }
}

Answer 2

If you're trying to validate an email, use String.matches(regex)

Here is an imlementation of the email regex validation patter from this site . An explanation of the regex can also be found on the site.

private static final String EMAIL_PATTERN = 
    "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
    + "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";

if (!email.matches(EMAIL_PATTERN)) {}