Java实现邮件收发

一. 准备工作

1. 传输协议

SMTP协议-->发送邮件：
我们通常把处理用户smtp请求(邮件发送请求)的服务器称之为SMTP服务器(邮件发送服务器)

POP3协议-->接收邮件：
我们通常把处理用户pop3请求(邮件接收请求)的服务器称之为POP3服务器(邮件接收服务器)

2. 邮件收发原理

1. 闪电侠网易云邮箱通过smtp协议连接到Smtp服务器，然后发送一封邮件给网易的邮件服务器
2. 网易分析发现需要去QQ的邮件服务器，通过smtp协议将邮件转投给QQ的Smtp服务器
3. QQ将接收到的邮件存储在 962113063@qq.com这个邮件账号的空间中
4. 闪电侠qq邮箱通过Pop3协议连接到Pop3服务器收取邮件
5. 从 962113063@qq.com这个邮件账号的空间中取出邮件
6. Pop3服务器将取出来的邮件送到闪电侠qq邮箱中

3. QQ邮箱中获取对应的权限

QQ邮箱需要安全验证，我们需要获取他对应的权限；
QQ邮箱-->邮箱设置-->账户

4. 导入jar包

mail.jar
activation.ja

二. Java发送纯文本邮件

编写测试代码

public class SendMain {
    public static void main(String[] args) throws GeneralSecurityException, MessagingException {
    Properties prop = <span class="hljs-keyword">new</span> Properties();
    <span class="hljs-comment">//设置QQ邮件服务器</span>
    prop.setProperty(<span class="hljs-string">"mail.host"</span>, <span class="hljs-string">"smtp.qq.com"</span>);
    <span class="hljs-comment">//邮件发送协议</span>
    prop.setProperty(<span class="hljs-string">"mail.transport.protocol"</span>, <span class="hljs-string">"smtp"</span>);
    <span class="hljs-comment">//需要验证用户名密码</span>
    prop.setProperty(<span class="hljs-string">"mail.smtp.auth"</span>, <span class="hljs-string">"true"</span>);

    <span class="hljs-comment">//关于QQ邮箱，还要设置SSL加密，加上以下代码即可</span>
    MailSSLSocketFactory sf = <span class="hljs-keyword">new</span> MailSSLSocketFactory();
    sf.setTrustAllHosts(<span class="hljs-keyword">true</span>);
    prop.put(<span class="hljs-string">"mail.smtp.ssl.enable"</span>, <span class="hljs-string">"true"</span>);
    prop.put(<span class="hljs-string">"mail.smtp.ssl.socketFactory"</span>, sf);

    <span class="hljs-comment">//使用JavaMail发送邮件的5个步骤</span>
    <span class="hljs-comment">//1.txt、创建定义整个应用程序所需的环境信息的Session对象</span>
    Session session = Session.getDefaultInstance(prop, <span class="hljs-keyword">new</span> Authenticator() {
        <span class="hljs-function"><span class="hljs-keyword">public</span> PasswordAuthentication <span class="hljs-title">getPasswordAuthentication</span><span class="hljs-params">()</span> </span>{
            <span class="hljs-comment">//发件人邮件用户名、授权码</span>
            <span class="hljs-keyword">return</span> <span class="hljs-keyword">new</span> PasswordAuthentication(<span class="hljs-string">"962113063@qq.com"</span>,
                    <span class="hljs-string">"授权码"</span>);
        }
    });

    <span class="hljs-comment">//开启Session的debug模式，这样就可以查看到程序发送Email的运行状态</span>
    session.setDebug(<span class="hljs-keyword">true</span>);

    <span class="hljs-comment">//2、通过session得到transport对象</span>
    Transport ts = session.getTransport();

    <span class="hljs-comment">//3、使用邮箱的用户名和授权码连上邮件服务器</span>
    ts.connect(<span class="hljs-string">"smtp.qq.com"</span>, <span class="hljs-string">"962113063@qq.com"</span>, <span class="hljs-string">"授权码"</span>);

    <span class="hljs-comment">//4，创建邮件</span>
    <span class="hljs-comment">//4-1.txt，创建邮件对象</span>
    MimeMessage message = <span class="hljs-keyword">new</span> MimeMessage(session);

    <span class="hljs-comment">//4-2，指明邮件的发件人</span>
    message.setFrom(<span class="hljs-keyword">new</span> InternetAddress(<span class="hljs-string">"962113063@qq.com"</span>));

    <span class="hljs-comment">//4-3，指明邮件的收件人</span>
    message.setRecipient(Message.RecipientType.TO, <span class="hljs-keyword">new</span> InternetAddress(<span class="hljs-string">"962113063@qq.com"</span>));

    <span class="hljs-comment">//4-4，邮件标题</span>
    message.setSubject(<span class="hljs-string">"Hello"</span>);

    <span class="hljs-comment">//4-5，邮件文本内容</span>
    message.setContent(<span class="hljs-string">"我是钢铁侠！"</span>, <span class="hljs-string">"text/html;charset=UTF-8"</span>);

    <span class="hljs-comment">//4-6，发送邮件</span>
    ts.sendMessage(message, message.getAllRecipients());

    <span class="hljs-comment">//5，关闭连接</span>
    ts.close();
}

}

三. Java发送创建包含内嵌图片的邮件

1. 导入图片

2. 编写测试代码

public class SendMainpicture1 {
    public static void main(String[] args)throws GeneralSecurityException, MessagingException{
        Properties prop = new Properties();
        //设置QQ邮件服务器
        prop.setProperty("mail.host", "smtp.qq.com");
        //邮件发送协议
        prop.setProperty("mail.transport.protocol", "smtp");
        //需要验证用户名密码
        prop.setProperty("mail.smtp.auth", "true");
    <span class="hljs-comment">//关于QQ邮箱，还要设置SSL加密，加上以下代码即可</span>
    MailSSLSocketFactory sf = <span class="hljs-keyword">new</span> MailSSLSocketFactory();
    sf.setTrustAllHosts(<span class="hljs-keyword">true</span>);
    prop.put(<span class="hljs-string">"mail.smtp.ssl.enable"</span>, <span class="hljs-string">"true"</span>);
    prop.put(<span class="hljs-string">"mail.smtp.ssl.socketFactory"</span>, sf);

    <span class="hljs-comment">//使用JavaMail发送邮件的5个步骤</span>
    <span class="hljs-comment">//1.txt、创建定义整个应用程序所需的环境信息的Session对象</span>
    Session session = Session.getDefaultInstance(prop, <span class="hljs-keyword">new</span> Authenticator() {
        <span class="hljs-function"><span class="hljs-keyword">public</span> PasswordAuthentication <span class="hljs-title">getPasswordAuthentication</span><span class="hljs-params">()</span> </span>{
            <span class="hljs-comment">//发件人邮件用户名、授权码</span>
            <span class="hljs-keyword">return</span> <span class="hljs-keyword">new</span> PasswordAuthentication(<span class="hljs-string">"962113063@qq.com"</span>,
                    <span class="hljs-string">"授权码"</span>);
        }
    });
    <span class="hljs-comment">//开启Session的debug模式，这样就可以查看到程序发送Email的运行状态</span>
    session.setDebug(<span class="hljs-keyword">true</span>);

    <span class="hljs-comment">//2、通过session得到transport对象</span>
    Transport ts = session.getTransport();
    <span class="hljs-comment">//3、使用邮箱的用户名和授权码连上邮件服务器</span>
    ts.connect(<span class="hljs-string">"smtp.qq.com"</span>, <span class="hljs-string">"962113063@qq.com"</span>, <span class="hljs-string">"授权码"</span>);
    <span class="hljs-comment">//4，创建邮件</span>
    <span class="hljs-comment">//4-1.txt，创建邮件对象</span>
    MimeMessage message = <span class="hljs-keyword">new</span> MimeMessage(session);
    <span class="hljs-comment">//4-2，指明邮件的发件人</span>
    message.setFrom(<span class="hljs-keyword">new</span> InternetAddress(<span class="hljs-string">"962113063@qq.com"</span>));
    <span class="hljs-comment">//4-3，指明邮件的收件人</span>
    message.setRecipient(Message.RecipientType.TO, <span class="hljs-keyword">new</span> InternetAddress(<span class="hljs-string">"962113063@qq.com"</span>));
    <span class="hljs-comment">//4-4，邮件标题</span>
    message.setSubject(<span class="hljs-string">"Hello,钢铁侠"</span>);
    <span class="hljs-comment">//5.准备图片</span>
    MimeBodyPart image = <span class="hljs-keyword">new</span> MimeBodyPart();
    DataHandler dh = <span class="hljs-keyword">new</span> DataHandler(<span class="hljs-keyword">new</span> FileDataSource(<span class="hljs-string">"src/resources/9.jpg"</span>));
    image.setDataHandler(dh);
    image.setContentID(<span class="hljs-string">"9.jpg"</span>);
    <span class="hljs-comment">//6.准备正文数据</span>
    MimeBodyPart text = <span class="hljs-keyword">new</span> MimeBodyPart();
    text.setContent(<span class="hljs-string">"这是一封邮件正文带图片&lt;img src='cid:9.jpg'&gt;的邮件"</span>, <span class="hljs-string">"text/html;charset=UTF-8"</span>);
    <span class="hljs-comment">//7.描述数据关系</span>
    MimeMultipart mm = <span class="hljs-keyword">new</span> MimeMultipart();
    mm.addBodyPart(text);
    mm.addBodyPart(image);
    mm.setSubType(<span class="hljs-string">"related"</span>);
    <span class="hljs-comment">//设置到消息中，保存修改</span>
    message.setContent(mm);
    message.saveChanges();
    <span class="hljs-comment">//发送邮件</span>
    ts.sendMessage(message, message.getAllRecipients());
    ts.close();
}

}

四. Java发送带图片和附件的复杂邮件

1. 导入附件和图片

2. 编写测试代码

public class SendMainpicture2 {
    public static void main(String[] args) throws GeneralSecurityException, MessagingException {
        Properties prop = new Properties();
        //设置QQ邮件服务器
        prop.setProperty("mail.host", "smtp.qq.com");
        //邮件发送协议
        prop.setProperty("mail.transport.protocol", "smtp");
        //需要验证用户名密码
        prop.setProperty("mail.smtp.auth", "true");
    <span class="hljs-comment">//关于QQ邮箱，还要设置SSL加密，加上以下代码即可</span>
    MailSSLSocketFactory sf = <span class="hljs-keyword">new</span> MailSSLSocketFactory();
    sf.setTrustAllHosts(<span class="hljs-keyword">true</span>);
    prop.put(<span class="hljs-string">"mail.smtp.ssl.enable"</span>, <span class="hljs-string">"true"</span>);
    prop.put(<span class="hljs-string">"mail.smtp.ssl.socketFactory"</span>, sf);

    <span class="hljs-comment">//使用JavaMail发送邮件的5个步骤</span>
    <span class="hljs-comment">//1.txt、创建定义整个应用程序所需的环境信息的Session对象</span>
    Session session = Session.getDefaultInstance(prop, <span class="hljs-keyword">new</span> Authenticator() {
        <span class="hljs-function"><span class="hljs-keyword">public</span> PasswordAuthentication <span class="hljs-title">getPasswordAuthentication</span><span class="hljs-params">()</span> </span>{
            <span class="hljs-comment">//发件人邮件用户名、授权码</span>
            <span class="hljs-keyword">return</span> <span class="hljs-keyword">new</span> PasswordAuthentication(<span class="hljs-string">"962113063@qq.com"</span>,
                    <span class="hljs-string">"授权码"</span>);
        }
    });
    <span class="hljs-comment">//可以通过session开启Dubug模式，查看所有的过程</span>
    session.setDebug(<span class="hljs-keyword">true</span>);


    <span class="hljs-comment">//2.获取连接对象，通过session对象获得Transport，需要捕获或者抛出异常；</span>
    Transport tp = session.getTransport();
    <span class="hljs-comment">//3.连接服务器,需要抛出异常；</span>
    tp.connect(<span class="hljs-string">"smtp.qq.com"</span>,<span class="hljs-string">"962113063@qq.com"</span>,<span class="hljs-string">"授权码"</span>);
    <span class="hljs-comment">//4.连接上之后我们需要发送邮件；</span>
    MimeMessage mimeMessage = imageMail(session);
    <span class="hljs-comment">//5.发送邮件</span>
    tp.sendMessage(mimeMessage,mimeMessage.getAllRecipients());
    <span class="hljs-comment">//6.关闭连接</span>
    tp.close();
}

<span class="hljs-function"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> MimeMessage <span class="hljs-title">imageMail</span><span class="hljs-params">(Session session)</span> <span class="hljs-keyword">throws</span> MessagingException </span>{
    <span class="hljs-comment">//消息的固定信息</span>
    MimeMessage mimeMessage = <span class="hljs-keyword">new</span> MimeMessage(session);
    <span class="hljs-comment">//邮件发送人</span>
    mimeMessage.setFrom(<span class="hljs-keyword">new</span> InternetAddress(<span class="hljs-string">"962113063@qq.com"</span>));
    <span class="hljs-comment">//邮件接收人，可以同时发送给很多人</span>
    mimeMessage.setRecipient(Message.RecipientType.TO, <span class="hljs-keyword">new</span> InternetAddress(<span class="hljs-string">"624794851@qq.com"</span>));
    mimeMessage.setSubject(<span class="hljs-string">"我也不知道是个什么东西就发给你了"</span>); <span class="hljs-comment">//邮件主题</span>

    <span class="hljs-comment">//图片</span>
    MimeBodyPart body1 = <span class="hljs-keyword">new</span> MimeBodyPart();
    body1.setDataHandler(<span class="hljs-keyword">new</span> DataHandler(<span class="hljs-keyword">new</span> FileDataSource(<span class="hljs-string">"src/resources/9.jpg"</span>)));
    body1.setContentID(<span class="hljs-string">"9.jpg"</span>); <span class="hljs-comment">//图片设置ID</span>

    <span class="hljs-comment">//文本</span>
    MimeBodyPart body2 = <span class="hljs-keyword">new</span> MimeBodyPart();
    body2.setContent(<span class="hljs-string">"请注意，我不是广告&lt;img src='cid:9.jpg'&gt;"</span>,<span class="hljs-string">"text/html;charset=utf-8"</span>);

    <span class="hljs-comment">//附件</span>
    MimeBodyPart body3 = <span class="hljs-keyword">new</span> MimeBodyPart();
    body3.setDataHandler(<span class="hljs-keyword">new</span> DataHandler(<span class="hljs-keyword">new</span> FileDataSource(<span class="hljs-string">"src/resources/log4j.properties"</span>)));
    body3.setFileName(<span class="hljs-string">"log4j.properties"</span>); <span class="hljs-comment">//附件设置名字</span>

    MimeBodyPart body4 = <span class="hljs-keyword">new</span> MimeBodyPart();
    body4.setDataHandler(<span class="hljs-keyword">new</span> DataHandler(<span class="hljs-keyword">new</span> FileDataSource(<span class="hljs-string">"src/resources/1.txt"</span>)));
    body4.setFileName(<span class="hljs-string">"1.txt"</span>); <span class="hljs-comment">//附件设置名字</span>

    <span class="hljs-comment">//拼装邮件正文内容</span>
    MimeMultipart multipart1 = <span class="hljs-keyword">new</span> MimeMultipart();
    multipart1.addBodyPart(body1);
    multipart1.addBodyPart(body2);
    multipart1.setSubType(<span class="hljs-string">"related"</span>); <span class="hljs-comment">//1.txt.文本和图片内嵌成功！</span>

    <span class="hljs-comment">//new MimeBodyPart().setContent(multipart1); //将拼装好的正文内容设置为主体</span>
    MimeBodyPart contentText =  <span class="hljs-keyword">new</span> MimeBodyPart();
    contentText.setContent(multipart1);

    <span class="hljs-comment">//拼接附件</span>
    MimeMultipart allFile =<span class="hljs-keyword">new</span> MimeMultipart();
    allFile.addBodyPart(body3); <span class="hljs-comment">//附件</span>
    allFile.addBodyPart(body4); <span class="hljs-comment">//附件</span>
    allFile.addBodyPart(contentText);<span class="hljs-comment">//正文</span>
    allFile.setSubType(<span class="hljs-string">"mixed"</span>); <span class="hljs-comment">//正文和附件都存在邮件中，所有类型设置为mixed；</span>

    <span class="hljs-comment">//放到Message消息中</span>
    mimeMessage.setContent(allFile);
    mimeMessage.saveChanges();<span class="hljs-comment">//保存修改</span>

    <span class="hljs-keyword">return</span> mimeMessage;
}

}