How to Open the Default Mail Application in Java to Create and Populate a New Email?

How can I open the default email application in Java and automatically fill in the To and Subject fields when creating a new email?

String recipient = "[email protected]";
String subject = "Hello";
String body = "This is a test email.";

String mailto = String.format("mailto:%s?subject=%s&body=%s", recipient, subject, body);
java.awt.Desktop.getDesktop().mail(new URI(mailto));

In Java, you can use the Desktop class to open the default mail application and pre-fill certain fields like 'To' and 'Subject'. This is achieved by creating a mailto URI which the default email client recognizes and uses to populate your email fields accordingly.

import java.awt.Desktop;
import java.net.URI;

public class MailClientExample {
    public static void main(String[] args) throws Exception {
        String recipient = "[email protected]";
        String subject = "Hello";
        String body = "This is a test email.";

        String mailto = String.format("mailto:%s?subject=%s&body=%s", recipient, subject, body);
        Desktop.getDesktop().mail(new URI(mailto));
    }
}

Causes

• User needs to send an email programmatically.
• Integration with mail services is required.

Solutions

• Use the Desktop class from the awt package to launch the mail client.
• Construct a properly formatted mailto URI with parameters.

Mistake: Not handling the unsupported Desktop functionality on some operating systems.

Solution: Check if Desktop.isDesktopSupported() and Desktop.getDesktop().isMailSupported() before trying to send email.

Mistake: Incorrectly formatting the URI which causes the mail client not to open.

Solution: Ensure proper URL encoding for special characters in the subject or body.