java - 如何使用JAVA代码发送电子邮件？

Question

import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
import javax.activation.*;

public class SendEMail
{
   public static void main(String [] args)
 {

  // Recipient's email ID needs to be mentioned.
  String to = "*********@gmail.com";

  // Sender's email ID needs to be mentioned
  String from = "********@gmail.com";

  // Assuming you are sending email from localhost
  String host = "465";

  // Get system properties
  Properties properties = System.getProperties();

  // Setup mail server
  properties.setProperty("mail.smtp.port", host);
  properties.put("mail.smtp.user", "*****");
  properties.put("mail.smtp.host", "smtp.gmail.com");
  properties.put("mail.smtp.port", "587");
  properties.put("mail.smtp.starttls.enable","true");
  properties.put("mail.smtp.debug", "true");
  properties.put("mail.smtp.auth", "true");
  properties.put("mail.smtp.socketFactory.port", "587");
  properties.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
  properties.put("mail.smtp.socketFactory.fallback", "false");
  properties.setProperty("mail.user", "*******");
  properties.setProperty("mail.password", "******");

  // Get the default Session object.
  Session session = Session.getDefaultInstance(properties);

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

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

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

     // Set Subject: header field
     message.setSubject("This is the Subject Line!");

     // Create the message part 
     BodyPart messageBodyPart = new MimeBodyPart();

     // Fill the message
     messageBodyPart.setText("This is message body");

     // Create a multipar message
     Multipart multipart = new MimeMultipart();

     // Set text message part
     multipart.addBodyPart(messageBodyPart);

     // Part two is attachment
     messageBodyPart = new MimeBodyPart();
     String filename = "file.txt";
     DataSource source = new FileDataSource(filename);
     messageBodyPart.setDataHandler(new DataHandler(source));
     messageBodyPart.setFileName(filename);
     multipart.addBodyPart(messageBodyPart);

     // Send the complete message parts
     message.setContent(multipart );

     // Send message
     Transport.send(message);
     System.out.println("Sent message successfully....");
  }catch (MessagingException mex) {
     mex.printStackTrace();
    }
   }
  }

我收到以下错误。 错误:

javax.mail.SendFailedException: Sending failed;
nested exception is:
class javax.mail.AuthenticationFailedException

在浏览同一页面的建议后。我修改了代码，如上所示。但是，这次我收到身份验证错误。请帮我看看这次我哪里错了？

Answer 1

  properties.setProperty("mail.smtp.host", host);

这里，主机不是您发送电子邮件的机器。(如代码注释中所写)。 它是您的电子邮件服务器所在的主机。

对于 gmail - 端口 465 上的 smtp.gmail.com。

您必须根据您的 smtp 服务器进行配置。