用Java发送邮件

了解

电子邮件要在网络上实现邮件功能，必须要有专门的邮件服务器。
这些邮件服务器类似于现实生活中的邮局，它主要负责接收用户投递过来的邮件，并把邮件投递到邮件接收者的电子邮箱中。
SMTP服务器地址：一般是 smtp.xxx.com，比如163邮箱是smtp.163.com，qq邮箱是smtp.qq.com。

使用Java发送 E-mail 十分简单，但是首先你应该准备 JavaMail API 和Java Activation Framework 。
得到两个jar包：

• mail.jar
• activation.jar

导入纯文本邮件

1.导包并获取权限
先导入上面说的2个jar包,然后从QQ邮箱中获取对应的权限:在qq邮箱设置-账户-开启POP3/SMTP服务可以获得授权码

2.编写代码

package com.yamobo;
import com.sun.mail.util.MailSSLSocketFactory;
import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.security.GeneralSecurityException;
import java.util.Properties;
public class SendEmail {
    public static void main(String[] args) throws GeneralSecurityException, MessagingException {
        Properties prop = new Properties();
        prop.setProperty("mail.host","smtp.qq.com");//设置qq邮件服务器
        prop.setProperty("mail.transport.protocol","smtp");//邮件发送协议
        prop.setProperty("mail.smtp.auth","true");//需要验证服务器密码
//qq邮箱还需要设置SSL加密
        MailSSLSocketFactory sf = new MailSSLSocketFactory();
        sf.setTrustAllHosts(true);
        prop.put("mail.smtp.ssl.enable","true");
        prop.put("mail.smtp.ssl.socketFactory",sf);
        //使用JavaMail发送邮件的五个步骤
        //1.创建定义整个应用程序所需的环境信息的session对象
        Session session= Session.getDefaultInstance(prop, new Authenticator() {
            public PasswordAuthentication getPasswordAuthentication(){
                //发件人邮件用户名,授权码
                return  new PasswordAuthentication("发件人qq邮箱地址","授权码");
            }

        });
        //开启Session的debug模式,这样可以查看程序发送的Email运行状态
            session.setDebug(true);
            //2.通过session得到transport对象
        Transport ts = session.getTransport();
        //3.使用邮箱的用户名和授权码连上邮件服务器
        ts.connect("smtp.qq.com","发件人qq邮箱地址","授权码");
        //4.创建邮件
        MimeMessage message = new MimeMessage(session);
       //设置邮件的基本信息
       指明发件人
        message.setFrom(new InternetAddress("发件人qq邮箱地址"));
       //指明收件人 
        message.setRecipient(Message.RecipientType.TO,new InternetAddress("收件人qq邮箱地址"));
        //标题
        message.setSubject("纯文本测试");
       //文本内容
        message.setContent("收到了吗","text/html;charset=UTF-8");
       //5.发送邮件
        ts.sendMessage(message,message.getAllRecipients());
        ts.close();
    }
    }

带图片和附件的复杂邮件发送

package com.yamobo;

import com.sun.mail.util.MailSSLSocketFactory;

import javax.activation.DataHandler;
import javax.activation.FileDataSource;
import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import java.security.GeneralSecurityException;
import java.util.Properties;

public class SendFileEmail {
    public static void main(String[] args) throws GeneralSecurityException, MessagingException {
        Properties prop = new Properties();
        prop.setProperty("mail.host","smtp.qq.com");
        prop.setProperty("mail.transport.protocol","smtp");
        prop.setProperty("mail.smtp.auth","true");

        MailSSLSocketFactory sf = new MailSSLSocketFactory();
        sf.setTrustAllHosts(true);
        prop.put("mail.smtp.ssl.enable", "true");
        prop.put("mail.smtp.ssl.socketFactory", sf);
        Session session = Session.getDefaultInstance(prop, new Authenticator() {
            public PasswordAuthentication getPasswordAuthentication() {
                //发件人邮件用户名、授权码
                return new PasswordAuthentication("@qq.com", "bbpuvjfyzeflbebf");
            }
        });
        session.setDebug(true);
        Transport ts = session.getTransport();
        ts.connect("smtp.qq.com", "@qq.com", "bbpuvjfyzeflbebf");

        MimeMessage message = new MimeMessage(session);

        message.setFrom(new InternetAddress("@qq.com"));
        message.setRecipient(Message.RecipientType.TO, new InternetAddress("@qq.com"));
        message.setSubject("带附件和带图片的的邮件");

        MimeBodyPart image = new MimeBodyPart();
        image.setDataHandler(new DataHandler(new FileDataSource("src/resources/bz.jpg")));
        image.setContentID("bz.jpg");

        //正文
        MimeBodyPart text = new MimeBodyPart();
        text.setContent("不用啊<br/><img src='cid:bz.jpg'>","text/html;charset=UTF-8");

        //附件1

        MimeBodyPart attach = new MimeBodyPart();
        attach.setDataHandler(new DataHandler(new FileDataSource("src/resources/1.txt")));
        attach.setFileName("1.txt");
        //描述关系:正文和图片

        MimeMultipart mp1 = new MimeMultipart();
        mp1.addBodyPart(text);
        mp1.addBodyPart(image);
        mp1.setSubType("related");
        //描述关系:正文和附件

        MimeMultipart mp2 = new MimeMultipart();
        mp2.addBodyPart(attach);
        //代表正文的bodypart
        MimeBodyPart content = new MimeBodyPart();
        content.setContent(mp1);
     
        mp2.addBodyPart(content);
        mp2.setSubType("mixed");
        //发送邮件
        message.setContent(mp2);
        message.saveChanges();ts.sendMessage(message, message.getAllRecipients());
    
        ts.close();

    }
}