使用 servlet 发送电子邮件

Question

我必须通过 servlet 发送电子邮件，我尝试了很多代码，但它们都不能用于 gmail 帐户，有什么想法吗？

 java.security.Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
        Properties props = new Properties();
        props.put("mail.transport.protocol", "smtp");
        props.put("mail.smtp.starttls.enable","true");
        props.put("mail.smtp.host", "smtp.gmail.com");
        props.put("mail.smtp.auth", "true");

        Authenticator auth =  new SMTPAuthenticator();
        //auth = null;
        Session sess = Session.getInstance(props, auth);

        sess.setDebug(false);
           // -- Create a new message --
           Message msg = new MimeMessage(sess);

           // -- Set the FROM and TO fields --
           msg.setFrom(new InternetAddress("myemail@gmail.com"));
           msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(
             "sendtoemail", false));
           msg.setSubject("Test");
           msg.setText("Yippe");
           msg.setSentDate(new Date());
           Transport.send(msg);

           public class SMTPAuthenticator extends javax.mail.Authenticator {
           @Override
           public PasswordAuthentication getPasswordAuthentication() {
           String username = "myemail@gmail.com";
           String password = "mypass";
           return new PasswordAuthentication(username, password);
           }

}

此代码抛出 javax.mail.MessagingException: Could not convert socket to TLS 异常

Answer 1

只是切换到 commons-email 不会消除此异常。此外，切换到 commons-email 会导致异常中有用信息的数量减少 - 异常日志中的以下行将不再存在：

nested exception is:
    javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: 
    sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

在这种情况下，真正的线索是嵌套异常。

要修复它，您需要将电子邮件服务器证书安装到 JVM 密钥库。默认密钥库的位置取决于 java 发行版。就我而言，它是/etc/java-6-sun/security/cacert

添加证书后认证成功。

Answer 2

使用commons-email

public static Email createMail(){
    Email email = SimpleEmail();


    email.setHostName(Settings.getValue("smtp.host"));
    email.setSmtpPort(Integer.parseInt(Settings.getValue("smtp.port")));
    String username = Settings.getValue("smtp.user");
    if (username.length() > 0) {
        email.setAuthentication(username, Settings.getValue("smtp.password"));
    }

    boolean useSSL = false;
    try {
        useSSL = Boolean.parseBoolean(Settings.getValue("smtp.ssl"));
    } catch (Exception ex) {
        // ignore - property not set
    }

    email.setSSL(useSSL);
    email.setCharset("utf-8");

    return email;
}

public sendMail(String recipientEmail) {
     Email email = createMail();
     email.addTo(recipientEmail);
     email.setFrom("no-reply@example.org");
     email.setSubject("Your subject herE");
     email.setMsg("Your message here");
     email.send();
}