JAVA代码发送邮件示例和解释

package test;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.mail.Address;
import javax.mail.Authenticator;
import javax.mail.BodyPart;
import javax.mail.Message;
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 com.sun.mail.util.MailSSLSocketFactory;

///**
// * 
// * @author tuzongxun123
// * @Description 邮件发送测试类
// */
public class sendMailTest {
    public static void main(String[] args) throws Exception {
        // 配置信息
        Properties pro = new Properties();
        pro.put("mail.smtp.host", "smtp.163.com");
        pro.put("mail.smtp.auth", "true");
        // SSL加密
        MailSSLSocketFactory sf = null;
        sf = new MailSSLSocketFactory();
        // 设置信任所有的主机
        sf.setTrustAllHosts(true);
        pro.put("mail.smtp.ssl.enable", "true");
        pro.put("mail.smtp.ssl.socketFactory", sf);
        // 根据邮件的会话属性构造一个发送邮件的Session，这里需要注意的是用户名那里不能加后缀，否则便不是用户名了
        //还需要注意的是，这里的密码不是正常使用邮箱的登陆密码，而是客户端生成的另一个专门的授权码
        MailAuthenticator authenticator = new MailAuthenticator("tuzongxun123",
                "客户端授权码");
        Session session = Session.getInstance(pro, authenticator);
        // 根据Session 构建邮件信息
        Message message = new MimeMessage(session);
        // 创建邮件发送者地址
        Address from = new InternetAddress("tuzongxun123@163.com");
        // 设置邮件消息的发送者
        message.setFrom(from);
        // 验证收件人邮箱地址
        List<String> toAddressList = new ArrayList<>();
        toAddressList.add("1160569243@qq.com");
        StringBuffer buffer = new StringBuffer();
        if (!toAddressList.isEmpty()) {
            String regEx = "^([a-z0-9A-Z]+[-|\\.]?)+[a-z0-9A-Z]@([a-z0-9A-Z]+(-[a-z0-9A-Z]+)?\\.)+[a-zA-Z]{2,}$";
            Pattern p = Pattern.compile(regEx);
            for (int i = 0; i < toAddressList.size(); i++) {
                Matcher match = p.matcher(toAddressList.get(i));
                if (match.matches()) {
                    buffer.append(toAddressList.get(i));
                    if (i < toAddressList.size() - 1) {
                        buffer.append(",");
                    }
                }
            }
        }
        String toAddress = buffer.toString();
        if (!toAddress.isEmpty()) {
            // 创建邮件的接收者地址
            Address[] to = InternetAddress.parse(toAddress);
            // 设置邮件接收人地址
            message.setRecipients(Message.RecipientType.TO, to);
            // 邮件主题
            // message.setSubject("java邮件测试");
            message.setSubject("为什么错了");
            // 邮件容器
            MimeMultipart mimeMultiPart = new MimeMultipart();
            // 设置HTML
            BodyPart bodyPart = new MimeBodyPart();
            // 邮件内容
            // String htmlText = "java邮件测试111";
            String htmlText = "为什么错了";
            bodyPart.setContent(htmlText, "text/html;charset=utf-8");
            mimeMultiPart.addBodyPart(bodyPart);
          // 添加附件
            List<String> fileAddressList = new ArrayList<String>();
            fileAddressList
                    .add("C:\\Users\\tuzongxun123\\Desktop\\新建 Microsoft Office Word 文档.docx");
            if (fileAddressList != null) {
                BodyPart attchPart = null;
                for (int i = 0; i < fileAddressList.size(); i++) {
                    if (!fileAddressList.get(i).isEmpty()) {
                        attchPart = new MimeBodyPart();
                        // 附件数据源
                        DataSource source = new FileDataSource(
                                fileAddressList.get(i));
                        // 将附件数据源添加到邮件体
                        attchPart.setDataHandler(new DataHandler(source));
                        // 设置附件名称为原文件名
                        attchPart.setFileName(MimeUtility.encodeText(source
                                .getName()));
                        mimeMultiPart.addBodyPart(attchPart);
                    }
                }
            }
            message.setContent(mimeMultiPart);
            message.setSentDate(new Date());
            // 保存邮件
            message.saveChanges();
            // 发送邮件
            Transport.send(message);
        }
    }
}

class MailAuthenticator extends Authenticator {

    /**
     * 用户名
     */
    private String username;
    /**
     * 密码
     */
    private String password;

    /**
     * 创建一个新的实例 MailAuthenticator.
     * 
     * @param username
     * @param password
     */
    public MailAuthenticator(String username, String password) {
        this.username = username;
        this.password = password;
    }

    public String getPassword() {
        return password;
    }

    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(username, password);
    }

    public String getUsername() {
        return username;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public void setUsername(String username) {
        this.username = username;
    }

}