Java实现QQ邮箱发送给网易邮箱，发送邮件+附件

实现功能：

1. Java实现 QQ邮箱 给网易邮箱发送邮件
2. 获取邮件信息并下载邮件的附件

前置功能

案例以QQ邮箱为例说明：

1. 首先登录QQ邮箱将SMTP服务开启，会得到一个授权码。
   
   
2. 创建一个Springboot项目【mail-demo】
3. 引入依赖

<dependencies>

	
    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-mailartifactId>
    dependency>

    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-webartifactId>
    dependency>

    <dependency>
        <groupId>org.springframework.bootgroupId>
        <artifactId>spring-boot-starter-testartifactId>
        <scope>testscope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintagegroupId>
                <artifactId>junit-vintage-engineartifactId>
            exclusion>
        exclusions>
    dependency>
dependencies>

4. 工具类

package com.siro.mp.constant;

/**
 * @author starsea
 * @date 2023-02-09 14:56
 */
public class MailConstant {
    // 发件人qq邮箱地址
    public static final String qq_from = "xxxx";
    // 发件人qq邮箱密钥
    public static final String qq_from_password = "xxxx";

    // 发件人网易邮箱地址
    public static final String wy_from = "xxxx";
    // 发件人网易邮箱密钥
    public static final String wy_from_password = "xxxx";

    // 收件人的qq邮箱地址
    public static final String qq_to = "xxxx";
    // 收件人的网易邮箱地址
    public static final String wy_to = "xxxx";

    // 发件人邮箱的 SMTP 服务器地址
    public static String smtphost_wy = "smtp.163.com";
    // 发件人邮箱的 SMTP 服务器地址
    public static String smtphost_qq = "smtp.qq.com";
    // 邮箱的协议
    public static String protocol_smtp = "smtp";
    // 邮箱的协议
    public static final String proteocol_pop3 = "pop3";

    //端口号
    public static final String port = "110";
    //服务器地址
    public static final String servicePath = "pop.163.com";
}

5. 实现代码如下

1. 发送邮件

package com.siro.mp.utils;

import com.siro.mp.constant.MailConstant;
import lombok.extern.slf4j.Slf4j;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.mail.*;
import javax.mail.internet.*;
import java.util.Date;
import java.util.Properties;

/**
 * 发送邮件
 * qq邮箱 -> 网易邮箱
 *
 * @author starsea
 * @date 2023-02-10 13:52
 */
@Slf4j
public class SendMailUtils {

    /**
     * 发送邮件
     *
     * @param from          发件人
     * @param fromPwd       发件人密钥
     * @param to            收件人
     * @param subject       邮件主题
     * @param content       邮件内容
     * @param isIncludeMail 是否包含邮件
     * @param fileList      附件地址列表
     */
    public static void sendSimpleMail(String from, String fromPwd, String to, String subject, String content, boolean isIncludeMail, String[] fileList) {
        log.info("Start .....");
        // 1. 创建参数配置, 用于连接邮件服务器的参数配置
        Properties props = new Properties();
        // 使用的协议（JavaMail规范要求）
        props.setProperty("mail.transport.protocol", MailConstant.protocol_smtp);
        // 发件人的邮箱的 SMTP 服务器地址
        props.setProperty("mail.smtp.host", MailConstant.smtphost_qq);
        // 需要请求认证
        props.setProperty("mail.smtp.auth", "true");
        // 端口号
        props.setProperty("mail.smtp.port", "465");
        // qq邮箱必须设置这一项，ssl加密选项
//        props.setProperty("mail.smtp.ssl.enable", "true");

        // 创建Session对象,session对象表示整个邮件的环境信息
        Session session = Session.getInstance(props);
        // 设置输出调试信息
        session.setDebug(true);

        try {
            // Message的实例对象表示一封电子邮件
            MimeMessage message = new MimeMessage(session);
            // 设置发件人的地址
            message.setFrom(new InternetAddress(from));
            // 设置收件人
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            // 设置时间
            message.setSentDate(new Date());
            // 设置主题
            message.setSubject(subject);

            // 设置邮件的文本内容
            BodyPart bp = new MimeBodyPart();
            bp.setContent(content, "text/html;charset=utf-8");

            // 创建多重消息
            Multipart multipart = new MimeMultipart();
            multipart.addBodyPart(bp);

            if (isIncludeMail) {
                if (fileList != null && fileList.length > 0) {
                    for (int i = 0; i < fileList.length; i++) {
                        // 设置附件
                        bp = new MimeBodyPart();
                        DataSource source = new FileDataSource(fileList[i]);
                        DataHandler dh = new DataHandler(source);
                        bp.setDataHandler(dh);
                        bp.setFileName(MimeUtility.encodeText(source.getName(),"UTF-8", "B"));
                        multipart.addBodyPart(bp);
                    }
                }
            }
            message.setContent(multipart);
            message.saveChanges();

            // 从session的环境中获取发送邮件的对象
            Transport transport = session.getTransport();
            // 连接邮件服务器
            transport.connect(MailConstant.smtphost_qq, 25, from, fromPwd);
            // 设置收件人地址,并发送消息
            transport.sendMessage(message, new Address[]{new InternetAddress(to)});
            transport.close();

            log.info("End .....");
        } catch (Exception e) {
            log.error("发送邮件失败：{}", e);
        }
    }
}

测试

/**
* 发送邮件（工具类）
 */
@Test
public void sendMail() throws Exception {
    String subject = "测试工具类包含邮件";
    String content = "这是包含邮件的正文.....";
    String[] fileList = new String[2];
    fileList[0] = "C:\\Users\\GH\\Desktop\\狗子.docx";
    fileList[1] = "C:\\Users\\GH\\Desktop\\测试流程.docx";
    SendMailUtils.sendSimpleMail(MailConstant.qq_from, MailConstant.qq_from_password,
            MailConstant.wy_to, subject, content, true, fileList);
}

2. 获取邮件信息并下载对应附件

package com.siro.mp.utils;

import com.siro.mp.constant.MailConstant;
import lombok.extern.slf4j.Slf4j;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimeUtility;
import javax.mail.search.SearchTerm;
import javax.mail.search.SubjectTerm;
import java.io.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;

/**
 * 获取邮件信息并下载对应附件
 *
 * @author starsea
 * @date 2023-02-10 11:44
 */
@Slf4j
public class ReceiveEmailUtils {

    /**
     * 获取邮箱信息
     *
     * @param emailAddress 需要解析的邮箱地址
     * @param password    邮箱的授权密码  不是登录密码
     * @param projectName 邮箱中邮件标题
     * @throws Exception
     */
    public static void receive(String emailAddress, String password, String projectName) throws Exception {

        // 准备连接服务器的会话信息
        Properties props = new Properties();
        props.setProperty("mail.store.protocol", MailConstant.proteocol_pop3);
        props.setProperty("mail.pop3.port", MailConstant.port);
        props.setProperty("mail.pop3.host", MailConstant.servicePath);

        // 创建Session实例对象
        Session session = Session.getInstance(props);
        Store store = session.getStore(MailConstant.proteocol_pop3);
        store.connect(emailAddress, password); //163邮箱程序登录属于第三方登录所以这里的密码是163给的授权密码而并非普通的登录密码

        // 获得收件箱
        Folder folder = store.getFolder("INBOX");
        /* Folder.READ_ONLY：只读权限
         * Folder.READ_WRITE：可读可写（可以修改邮件的状态）
         */
        folder.open(Folder.READ_WRITE); //打开收件箱

//        // 由于POP3协议无法获知邮件的状态,所以getUnreadMessageCount得到的是收件箱的邮件总数
//        System.out.println("未读邮件数: " + folder.getUnreadMessageCount());
//
//        // 由于POP3协议无法获知邮件的状态,所以下面得到的结果始终都是为0
//        System.out.println("删除邮件数: " + folder.getDeletedMessageCount());
//        System.out.println("新邮件: " + folder.getNewMessageCount());

        // 获得收件箱中的邮件总数
        log.warn("邮件总数: {}", folder.getMessageCount());

        // 得到收件箱中的所有邮件,并解析
//        Message[] messages = folder.getMessages();

        //筛选邮件
//        SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd 01:00:00");
//        SearchTerm st=new AndTerm(new SubjectTerm("UpdateFromIESToCargo"),
//                new SentDateTerm(6,sf.parse(sf.format(new Date())))  );//6 代表大于等于这时间之后
        SearchTerm st = new SubjectTerm(projectName);
        Message[] messages = folder.search(st);

        //解析邮件
        parseMessage(messages);

        //得到收件箱中的所有邮件并且删除邮件
//        deleteMessage(messages);

        //释放资源
        folder.close(true);
        store.close();
    }

    /**
     * 解析邮件
     *
     * @param messages 要解析的邮件列表
     */
    public static void parseMessage(Message... messages) throws MessagingException, IOException {
        if (messages == null || messages.length < 1) {
            throw new MessagingException("未找到要解析的邮件!");
        }

        // 解析所有邮件
        for (int i = 0, count = messages.length; i < count; i++) {
            MimeMessage msg = (MimeMessage) messages[i];
            log.info("------------------解析第" + msg.getMessageNumber() + "封邮件-------------------- ");
            log.warn("主题: {}", getSubject(msg));
            log.warn("发件人: {}", getFrom(msg));
            log.warn("收件人：{}", getReceiveAddress(msg, null));
            log.warn("发送时间：{}", getSentDate(msg, null));
            log.warn("是否已读：{}", isSeen(msg));
            log.warn("邮件优先级：{}", getPriority(msg));
            log.warn("是否需要回执：{}", isReplySign(msg));
            log.warn("邮件大小：{}", msg.getSize() * 1024 + "kb");
            boolean isContainerAttachment = isContainAttachment(msg);
            log.warn("是否包含附件：{}", isContainerAttachment);
            if (isContainerAttachment) {
                saveAttachment(msg, "D:\\" + msg.getSubject() + "_" + i + "_"); //保存附件
            }
            StringBuffer content = new StringBuffer(30);
            //解析邮件正文
            getMailTextContent(msg, content);
            log.warn("邮件正文：{}", content);
            log.info("------------------第" + msg.getMessageNumber() + "封邮件解析结束-------------------- ");
            System.out.println();
        }
    }

    /**
     * 获得邮件主题
     *
     * @param msg 邮件内容
     * @return 解码后的邮件主题
     */
    public static String getSubject(MimeMessage msg) throws UnsupportedEncodingException, MessagingException {
        return MimeUtility.decodeText(msg.getSubject());
    }

    /**
     * 获得邮件发件人
     *
     * @param msg 邮件内容
     * @return 姓名 
     * @throws MessagingException
     * @throws UnsupportedEncodingException
     */
    public static String getFrom(MimeMessage msg) throws MessagingException, UnsupportedEncodingException {
        String from = "";
        Address[] froms = msg.getFrom();
        if (froms.length < 1) {
            throw new MessagingException("没有发件人!");
        }

        InternetAddress address = (InternetAddress) froms[0];
        String person = address.getPersonal();
        if (person != null) {
            person = MimeUtility.decodeText(person) + " ";
        } else {
            person = "";
        }
        from = person + "<" + address.getAddress() + ">";

        return from;
    }

    /**
     * 根据收件人类型，获取邮件收件人、抄送和密送地址。如果收件人类型为空，则获得所有的收件人
     * 
Message.RecipientType.TO  收件人
     * 
Message.RecipientType.CC  抄送
     * 
Message.RecipientType.BCC 密送
     *
     * @param msg  邮件内容
     * @param type 收件人类型
     * @return 收件人1 <邮件地址1>, 收件人2 <邮件地址2>, ...
     * @throws MessagingException
     */
    public static String getReceiveAddress(MimeMessage msg, Message.RecipientType type) throws MessagingException {
        StringBuffer receiveAddress = new StringBuffer();
        Address[] addresss = null;
        if (type == null) {
            addresss = msg.getAllRecipients();
        } else {
            addresss = msg.getRecipients(type);
        }

        if (addresss == null || addresss.length < 1) {
            throw new MessagingException("没有收件人!");
        }
        for (Address address : addresss) {
            InternetAddress internetAddress = (InternetAddress) address;
            receiveAddress.append(internetAddress.toUnicodeString()).append(",");
        }

        receiveAddress.deleteCharAt(receiveAddress.length() - 1); //删除最后一个逗号

        return receiveAddress.toString();
    }

    /**
     * 获得邮件发送时间
     *
     * @param msg 邮件内容
     * @return yyyy年mm月dd日 星期X HH:mm
     * @throws MessagingException
     */
    public static String getSentDate(MimeMessage msg, String pattern) throws MessagingException {
        Date receivedDate = msg.getSentDate();
        if (receivedDate == null) {
            return "";
        }

        if (pattern == null || "".equals(pattern)) {
            pattern = "yyyy年MM月dd日 E HH:mm ";
        }

        return new SimpleDateFormat(pattern).format(receivedDate);
    }

    /**
     * 判断邮件是否已读
     *
     * @param msg 邮件内容
     * @return 如果邮件已读返回true, 否则返回false
     * @throws MessagingException
     */
    public static boolean isSeen(MimeMessage msg) throws MessagingException {
        return msg.getFlags().contains(Flags.Flag.SEEN);
    }

    /**
     * 获得邮件的优先级
     *
     * @param msg 邮件内容
     * @return 1(High):紧急  3:普通(Normal)  5:低(Low)
     * @throws MessagingException
     */
    public static String getPriority(MimeMessage msg) throws MessagingException {
        String priority = "普通";
        String[] headers = msg.getHeader("X-Priority");
        if (headers != null) {
            String headerPriority = headers[0];
            if (headerPriority.indexOf("1") != -1 || headerPriority.indexOf("High") != -1) {
                priority = "紧急";
            } else if (headerPriority.indexOf("5") != -1 || headerPriority.indexOf("Low") != -1) {
                priority = "低";
            } else {
                priority = "普通";
            }
        }
        return priority;
    }

    /**
     * 判断邮件是否需要阅读回执
     *
     * @param msg 邮件内容
     * @return 需要回执返回true, 否则返回false
     * @throws MessagingException
     */
    public static boolean isReplySign(MimeMessage msg) throws MessagingException {
        boolean replySign = false;
        String[] headers = msg.getHeader("Disposition-Notification-To");
        if (headers != null) {
            replySign = true;
        }
        return replySign;
    }

    /**
     * 判断邮件中是否包含附件
     *
     * @param part 邮件内容
     * @return 邮件中存在附件返回true，不存在返回false
     * @throws MessagingException
     * @throws IOException
     */
    public static boolean isContainAttachment(Part part) throws MessagingException, IOException {
        boolean flag = false;
        if (part.isMimeType("multipart/*")) {
            MimeMultipart multipart = (MimeMultipart) part.getContent();
            int partCount = multipart.getCount();
            for (int i = 0; i < partCount; i++) {
                BodyPart bodyPart = multipart.getBodyPart(i);
                String disp = bodyPart.getDisposition();
                if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
                    flag = true;
                } else if (bodyPart.isMimeType("multipart/*")) {
                    flag = isContainAttachment(bodyPart);
                } else {
                    String contentType = bodyPart.getContentType();
                    if (contentType.indexOf("application") != -1) {
                        flag = true;
                    }

                    if (contentType.indexOf("name") != -1) {
                        flag = true;
                    }
                }

                if (flag) {
                    break;
                }
            }
        } else if (part.isMimeType("message/rfc822")) {
            flag = isContainAttachment((Part) part.getContent());
        }
        return flag;
    }

    /**
     * 文本解码
     *
     * @param encodeText 解码MimeUtility.encodeText(String text)方法编码后的文本
     * @return 解码后的文本
     * @throws UnsupportedEncodingException
     */
    public static String decodeText(String encodeText) throws UnsupportedEncodingException {
        if (encodeText == null || "".equals(encodeText)) {
            return "";
        } else {
            return MimeUtility.decodeText(encodeText);
        }
    }

    /**
     * 保存附件
     *
     * @param part    邮件中多个组合体中的其中一个组合体
     * @param destDir 附件保存目录
     * @throws UnsupportedEncodingException
     * @throws MessagingException
     * @throws FileNotFoundException
     * @throws IOException
     */
    public static void saveAttachment(Part part, String destDir) throws MessagingException, IOException {
        if (part.isMimeType("multipart/*")) {
            Multipart multipart = (Multipart) part.getContent();    //复杂体邮件
            //复杂体邮件包含多个邮件体
            int partCount = multipart.getCount();
            for (int i = 0; i < partCount; i++) {
                //获得复杂体邮件中其中一个邮件体
                BodyPart bodyPart = multipart.getBodyPart(i);
                //某一个邮件体也有可能是由多个邮件体组成的复杂体
                String disp = bodyPart.getDisposition();
                if (disp != null && (disp.equalsIgnoreCase(Part.ATTACHMENT) || disp.equalsIgnoreCase(Part.INLINE))) {
                    InputStream is = bodyPart.getInputStream();
                    saveFile(is, destDir, decodeText(bodyPart.getFileName()));
                } else if (bodyPart.isMimeType("multipart/*")) {
                    saveAttachment(bodyPart, destDir);
                } else {
                    String contentType = bodyPart.getContentType();
                    if (contentType.indexOf("name") != -1 || contentType.indexOf("application") != -1) {
                        saveFile(bodyPart.getInputStream(), destDir, decodeText(bodyPart.getFileName()));
                    }
                }
            }
        } else if (part.isMimeType("message/rfc822")) {
            saveAttachment((Part) part.getContent(), destDir);
        }
    }

    /**
     * 读取输入流中的数据保存至指定目录
     *
     * @param is       输入流
     * @param fileName 文件名
     * @param destDir  文件存储目录
     * @throws FileNotFoundException
     * @throws IOException
     */
    private static void saveFile(InputStream is, String destDir, String fileName) throws FileNotFoundException, IOException {
        BufferedInputStream bis = new BufferedInputStream(is);
        BufferedOutputStream bos = new BufferedOutputStream(
                new FileOutputStream(new File(destDir + fileName)));
        int len = -1;
        while ((len = bis.read()) != -1) {
            bos.write(len);
            bos.flush();
        }
        bos.close();
        bis.close();
    }

    /**
     * 获得邮件文本内容
     *
     * @param part    邮件体
     * @param content 存储邮件文本内容的字符串
     * @throws MessagingException
     * @throws IOException
     */
    public static void getMailTextContent(Part part, StringBuffer content) throws MessagingException, IOException {
        //如果是文本类型的附件，通过getContent方法可以取到文本内容，但这不是我们需要的结果，所以在这里要做判断
        boolean isContainTextAttach = part.getContentType().indexOf("name") > 0;
        if (part.isMimeType("text/*") && !isContainTextAttach) {
            content.append(part.getContent().toString());
        } else if (part.isMimeType("message/rfc822")) {
            getMailTextContent((Part) part.getContent(), content);
        } else if (part.isMimeType("multipart/*")) {
            Multipart multipart = (Multipart) part.getContent();
            int partCount = multipart.getCount();
            for (int i = 0; i < partCount; i++) {
                BodyPart bodyPart = multipart.getBodyPart(i);
                getMailTextContent(bodyPart, content);
            }
        }
    }

    /**
     * 删除邮件
     *
     * @param messages 要删除邮件列表
     */
    public static void deleteMessage(Message... messages) throws MessagingException, IOException {
        if (messages == null || messages.length < 1) {
            throw new MessagingException("未找到要解析的邮件!");
        }

        // 解析所有邮件
        for (int i = 0, count = messages.length; i < count; i++) {
            /**
             * 邮件删除
             */
            Message message = messages[i];
            String subject = message.getSubject();
            // set the DELETE flag to true
            message.setFlag(Flags.Flag.DELETED, true);
            System.out.println("Marked DELETE for message: " + subject);
        }
    }
}

测试

/**
 * 解析邮件并下载附件
 */
@Test
public void sendReceiveEmail() throws Exception {
    ReceiveEmailUtils.receive(MailConstant.wy_from, MailConstant.wy_from_password, "测试工具类发送简单邮件");
}

---

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