的JavaMail API错误

Question

我跟着this教程发送使用JavaMail API邮件，但它表明我这个错误，当我尝试运行代码：

Exception in thread "main" java.lang.RuntimeException: javax.mail.MessagingException: Could not convert socket to TLS; 
    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 
at SendEmail.main(SendEmail.java:64) 

我有javax.mail.jar文件中的类路径和我双重检查代码，它仍然无法正常工作。

这是代码：

import java.util.Properties; 
import javax.mail.Message; 
import javax.mail.MessagingException; 
import javax.mail.PasswordAuthentication; 
import javax.mail.Session; 
import javax.mail.Transport; 
import javax.mail.internet.InternetAddress; 
import javax.mail.internet.MimeMessage; 

public class SendEmail { 
public static void main(String[] args) { 
    // Recipient's email ID needs to be mentioned. 
    String to = "myemail@gmail.com"; 

    // Sender's email ID needs to be mentioned 
    String from = "javamailcoursework@gmail.com"; 
    final String username = "javamailcoursework@gmail.com";//change accordingly 
    final String password = "password";//change accordingly 

    // Assuming you are sending email through relay.jangosmtp.net 
    String host = "smtp.gmail.com"; 

    Properties props = new Properties(); 
    props.put("mail.smtp.auth", "true"); 
    props.put("mail.smtp.starttls.enable", "true"); 
    props.put("mail.smtp.host", "smtp.gmail.com"); 
    props.put("mail.smtp.port", "587"); 

    // Get the Session object. 
    Session session = Session.getInstance(props, 
    new javax.mail.Authenticator() { 
     protected PasswordAuthentication getPasswordAuthentication() { 
      return new PasswordAuthentication(username, password); 
    } 
    }); 

    try { 
    // Create a default MimeMessage object. 
    Message message = new MimeMessage(session); 

    // Set From: header field of the header. 
    message.setFrom(new InternetAddress(from)); 

    // Set To: header field of the header. 
    message.setRecipients(Message.RecipientType.TO, 
      InternetAddress.parse(to)); 

    // Set Subject: header field 
    message.setSubject("Testing Subject"); 

    // Now set the actual message 
    message.setText("Hello, this is sample for to check send " + 
    "email using JavaMailAPI "); 

    // Send message 
    Transport.send(message); 

    System.out.println("Sent message successfully...."); 

    } catch (MessagingException e) { 
    throw new RuntimeException(e); 
    } 

}}

Answer 1

添加并再次尝试。

props.put("mail.smtp.ssl.trust", "smtp.gmail.com");