How to implement the function of sending emails with attachments in Java

package com.ecg.controller; 
 
import java.io.UnsupportedEncodingException; 
import java.security.GeneralSecurityException; 
import java.util.Properties; 
 
import javax.activation.DataHandler; 
import javax.activation.DataSource; 
import javax.activation.FileDataSource; 
import javax.mail.Authenticator; 
import javax.mail.BodyPart; 
import javax.mail.Message; 
import javax.mail.MessagingException; 
import javax.mail.Multipart; 
import javax.mail.PasswordAuthentication; 
import javax.mail.Session; 
import javax.mail.Transport; 
import javax.mail.internet.InternetAddress; 
import javax.mail.internet.MimeBodyPart; 
import javax.mail.internet.MimeMessage; 
import javax.mail.internet.MimeMultipart; 
import javax.mail.internet.MimeUtility; 
 
import com.sun.mail.util.MailSSLSocketFactory; 
 
/** 
 * 邮件发送 
 * 
 * @author wanglongfei  
 * E-mail: islongfei@gmail.com 
 * @version 2017年8月27日 
 * 
 */ 
public class mailtest { 
 
 
 public static void main(String [] args) throws GeneralSecurityException, UnsupportedEncodingException 
 { 
  // 收件人电子邮箱 
  String to = "2528621082@qq.com"; 
 
  // 发件人电子邮箱 
  String from = "1135237317@qq.com"; 
 
  // 指定发送邮件的主机为 smtp.qq.com 
  String host = "smtp.qq.com"; //QQ 邮件服务器 
 
  // 获取系统属性 
  Properties properties = System.getProperties(); 
 
  // 设置邮件服务器 
  properties.setProperty("mail.smtp.host", host); 
 
  properties.put("mail.smtp.auth", "true"); 
  MailSSLSocketFactory sf = new MailSSLSocketFactory(); 
  sf.setTrustAllHosts(true); 
  properties.put("mail.smtp.ssl.enable", "true"); 
  properties.put("mail.smtp.ssl.socketFactory", sf); 
  // 获取默认session对象 
  Session session = Session.getDefaultInstance(properties,new Authenticator(){ 
   public PasswordAuthentication getPasswordAuthentication() 
   {  //qq邮箱服务器账户、第三方登录授权码 
    return new PasswordAuthentication("1135237317@qq.com", "dgahhkkjrtgafejj"); //发件人邮件用户名、密码 
   } 
  }); 
 
  try{ 
   // 创建默认的 MimeMessage 对象 
   MimeMessage message = new MimeMessage(session); 
 
   // Set From: 头部头字段 
   message.setFrom(new InternetAddress(from)); 
 
   // Set To: 头部头字段 
   message.addRecipient(Message.RecipientType.TO, new InternetAddress(to)); 
 
   // Set Subject: 主题文字 
   message.setSubject("家医康心电诊断结果"); 
 
    // 创建消息部分 
    BodyPart messageBodyPart = new MimeBodyPart(); 
  
    // 消息 
    messageBodyPart.setText("233333333333333"); 
 
    // 创建多重消息 
    Multipart multipart = new MimeMultipart(); 
  
    // 设置文本消息部分 
    multipart.addBodyPart(messageBodyPart); 
  
    // 附件部分 
    messageBodyPart = new MimeBodyPart(); 
    //设置要发送附件的文件路径 
    String filename = "C:/Users/下雨天-lalala/Desktop/家医康心电图/十二导联同步心电图-.png"; 
    DataSource source = new FileDataSource(filename); 
    messageBodyPart.setDataHandler(new DataHandler(source)); 
    
    //messageBodyPart.setFileName(filename); 
    //处理附件名称中文（附带文件路径）乱码问题 
    messageBodyPart.setFileName(MimeUtility.encodeText(filename)); 
    multipart.addBodyPart(messageBodyPart); 
  
    // 发送完整消息 
    message.setContent(multipart ); 
  
    // 发送消息 
    Transport.send(message); 
    System.out.println("Sent message successfully...."); 
   }catch (MessagingException mex) { 
    mex.printStackTrace(); 
   } 
 } 
}