Java实现邮件发送

雨点打透心脏的1/2处 2023-10-02 11:25 27阅读 0赞

### Java实现邮件发送 ###

#### 一、邮件服务器与传输协议 ####

*  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。
 *  SMTP协议
    
    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
    
    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)。

#### 二、Java发送邮件 ####

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使用到的jar包：

*  mail.jar
 *  activation.jar

QQ邮箱需获取相应的权限：

QQ邮箱–>邮箱设置–>账户–>POP3/IMAP/SMTP/Exchange/CardDAV/CalDAV服务 开启POP3/SMTP服务，然后获取16位授权码（注意不要将授权码泄露，一个账户可以拥有多个授权码）  
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**Java实现纯文本邮件发送**

package org.westos.email;
    
    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 SendEamil {
        
        public static void main(String[] args) throws MessagingException, GeneralSecurityException {
        
            //创建一个配置文件并保存
            Properties properties = new Properties();
    
            properties.setProperty("mail.host","smtp.qq.com");
    
            properties.setProperty("mail.transport.protocol","smtp");
    
            properties.setProperty("mail.smtp.auth","true");
    
    
            //QQ存在一个特性设置SSL加密
            MailSSLSocketFactory sf = new MailSSLSocketFactory();
            sf.setTrustAllHosts(true);
            properties.put("mail.smtp.ssl.enable", "true");
            properties.put("mail.smtp.ssl.socketFactory", sf);
    
            //创建一个session对象
            Session session = Session.getDefaultInstance(properties, new Authenticator() {
        
                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
        
                    return new PasswordAuthentication("619046217@qq.com","16位授权码");
                }
            });
    
            //开启debug模式
            session.setDebug(true);
    
            //获取连接对象
            Transport transport = session.getTransport();
    
            //连接服务器
            transport.connect("smtp.qq.com","619046217@qq.com","16位授权码");
    
            //创建邮件对象
            MimeMessage mimeMessage = new MimeMessage(session);
    
            //邮件发送人
            mimeMessage.setFrom(new InternetAddress("619046217@qq.com"));
    
            //邮件接收人
            mimeMessage.setRecipient(Message.RecipientType.TO,new InternetAddress("875203654@qq.com"));
    
            //邮件标题
            mimeMessage.setSubject("Hello Mail");
    
            //邮件内容
            mimeMessage.setContent("我的想法是把代码放进一个循环里","text/html;charset=UTF-8");
    
            //发送邮件
            transport.sendMessage(mimeMessage,mimeMessage.getAllRecipients());
    
            //关闭连接
            transport.close();
        }
    }

**Java实现文本图片附件复杂的邮件发送**  
MIME（多用途互联网邮件扩展类型）

MimeBodyPart类

javax.mail.internet.MimeBodyPart类 表示的是一个MIME消息，它和MimeMessage类一样都是从Part接口继承过来。

MimeMultipart类

javax.mail.internet.MimeMultipart是抽象类 Multipart的实现子类,它用来组合多个MIME消息。一个MimeMultipart对象可以包含多个代表MIME消息的MimeBodyPart对象

package org.westos.email;
    
    import com.sun.mail.util.MailSSLSocketFactory;
    
    import javax.activation.DataHandler;
    import javax.activation.FileDataSource;
    import javax.mail.*;
    import javax.mail.internet.*;
    import java.security.GeneralSecurityException;
    import java.util.Properties;
    
    public class SendComplexEmail {
        
        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"); // 需要验证用户名密码
    
            // QQ邮箱设置SSL加密
            MailSSLSocketFactory sf = new MailSSLSocketFactory();
            sf.setTrustAllHosts(true);
            prop.put("mail.smtp.ssl.enable", "true");
            prop.put("mail.smtp.ssl.socketFactory", sf);
    
            //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() {
        
                @Override
                protected PasswordAuthentication getPasswordAuthentication() {
        
                    //传入发件人的姓名和授权码
                    return new PasswordAuthentication("619046217@qq.com","16位授权码");
                }
            });
    
            //2、通过session获取transport对象
            Transport transport = session.getTransport();
    
            //3、通过transport对象邮箱用户名和授权码连接邮箱服务器
            transport.connect("smtp.qq.com","619046217@qq.com","16位授权码");
    
            //4、创建邮件,传入session对象
            MimeMessage mimeMessage = complexEmail(session);
    
            //5、发送邮件
            transport.sendMessage(mimeMessage,mimeMessage.getAllRecipients());
    
            //6、关闭连接
            transport.close();
    
    
        }
    
        public static MimeMessage complexEmail(Session session) throws MessagingException {
        
            //消息的固定信息
            MimeMessage mimeMessage = new MimeMessage(session);
    
            //发件人
            mimeMessage.setFrom(new InternetAddress("619046217@qq.com"));
            //收件人
            mimeMessage.setRecipient(Message.RecipientType.TO,new InternetAddress("619046217@qq.com"));
            //邮件标题
            mimeMessage.setSubject("带图片和附件的邮件");
    
            //邮件内容
            //准备图片数据
            MimeBodyPart image = new MimeBodyPart();
            DataHandler handler = new DataHandler(new FileDataSource("E:\\IdeaProjects\\WebEmail\\resources\\测试图片.png"));
            image.setDataHandler(handler);
            image.setContentID("test.png"); //设置图片id
    
            //准备文本
            MimeBodyPart text = new MimeBodyPart();
            text.setContent("这是一段文本<img src='cid:test.png'>","text/html;charset=utf-8");
    
            //附件
            MimeBodyPart appendix = new MimeBodyPart();
            appendix.setDataHandler(new DataHandler(new FileDataSource("E:\\IdeaProjects\\WebEmail\\resources\\测试文件.txt")));
            appendix.setFileName("test.txt");
    
            //拼装邮件正文
            MimeMultipart mimeMultipart = new MimeMultipart();
            mimeMultipart.addBodyPart(image);
            mimeMultipart.addBodyPart(text);
            mimeMultipart.setSubType("related");//文本和图片内嵌成功
    
            //将拼装好的正文内容设置为主体
            MimeBodyPart contentText = new MimeBodyPart();
            contentText.setContent(mimeMultipart);
    
            //拼接附件
            MimeMultipart allFile = new MimeMultipart();
            allFile.addBodyPart(appendix);//附件
            allFile.addBodyPart(contentText);//正文
            allFile.setSubType("mixed"); //正文和附件都存在邮件中，所有类型设置为mixed
    
    
            //放到Message消息中
            mimeMessage.setContent(allFile);
            mimeMessage.saveChanges();//保存修改
    
            return mimeMessage;
        }
    }

**JavaWeb发送邮件(网站注册成功发送提示邮件)**

1.  **User**
    
        package org.westos.mail;
        
        public class User {
              
            private String name;
            private String password;
            private String mail;
        
            public User() {
              
            }
        
            public User(String name, String password, String mail) {
              
                this.name = name;
                this.password = password;
                this.mail = mail;
            }
        
            public String getName() {
              
                return name;
            }
        
            public void setName(String name) {
              
                this.name = name;
            }
        
            public String getPassword() {
              
                return password;
            }
        
            public void setPassword(String password) {
              
                this.password = password;
            }
        
            public String getMail() {
              
                return mail;
            }
        
            public void setMail(String mail) {
              
                this.mail = mail;
            }
        
            @Override
            public String toString() {
              
                return "User{" +
                        "name='" + name + '\'' +
                        ", password='" + password + '\'' +
                        ", mail='" + mail + '\'' +
                        '}';
            }
        }
2.  Servlet
    
        package org.westos.mail;
        
        import javax.servlet.ServletException;
        import javax.servlet.http.HttpServletRequest;
        import javax.servlet.http.HttpServletResponse;
        import java.io.IOException;
        
        public class Servlet extends javax.servlet.http.HttpServlet {
              
            protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
              
                doGet(request,response);
            }
        
            protected void doGet(HttpServletRequest request, HttpServletResponse response) {
              
                //处理前端请求
                String username = request.getParameter("username");
                String password = request.getParameter("password");
                String email = request.getParameter("email");
        
                //将信息封装进user对象
                User user = new User(username, password, email);
        
                SendMail sendMail = new SendMail(user);
                sendMail.start(); //开启线程
        
                request.setAttribute("msg","发送成功");
                try {
              
                    request.getRequestDispatcher("msg.jsp").forward(request,response);
                } catch (ServletException e) {
              
                    e.printStackTrace();
                } catch (IOException e) {
              
                    e.printStackTrace();
                }
        
        
            }
        }
3.  **SengMail**
    
        package org.westos.mail;
        
        import com.sun.mail.util.MailSSLSocketFactory;
        
        import javax.mail.*;
        import javax.mail.internet.AddressException;
        import javax.mail.internet.InternetAddress;
        import javax.mail.internet.MimeMessage;
        import java.security.GeneralSecurityException;
        import java.security.PublicKey;
        import java.util.Properties;
        
        public class SendMail extends Thread {
              
            //发件人信息
            private String From = "619046217@qq.com";
            //发件人邮箱
            private String recipient = "619046217@qq.com";
            //邮箱密码
            private String password = "16位授权码";
            //邮件发送的服务器
            private String host = "smtp.qq.com";
        
            //收件人信息
            private User user;
            public SendMail(User user){
              
                this.user = user;
            }
        
            @Override
            public void run() {
              
                try {
              
                    Properties properties = new Properties();
        
                    properties.setProperty("mail.host","smtp.qq.com");
        
                    properties.setProperty("mail.transport.protocol","smtp");
        
                    properties.setProperty("mail.smtp.auth","true");
        
                    //QQ存在一个特性设置SSL加密
                    MailSSLSocketFactory sf = null;
                    try {
              
                        sf = new MailSSLSocketFactory();
                    } catch (GeneralSecurityException e) {
              
                        e.printStackTrace();
                    }
                    sf.setTrustAllHosts(true);
                    properties.put("mail.smtp.ssl.enable", "true");
                    properties.put("mail.smtp.ssl.socketFactory", sf);
        
                    //创建一个session对象
                    Session session = Session.getDefaultInstance(properties, new Authenticator() {
              
                        @Override
                        protected PasswordAuthentication getPasswordAuthentication() {
              
                            return new PasswordAuthentication(recipient,password);
                        }
                    });
        
                    //开启debug模式
                    session.setDebug(true);
        
                    //获取连接对象
                    Transport transport = null;
                    try {
              
                        transport = session.getTransport();
                    } catch (NoSuchProviderException e) {
              
                        e.printStackTrace();
                    }
        
                    //连接服务器
                    transport.connect(host,From,password);
        
        
                    //创建一个邮件发送对象
                    MimeMessage mimeMessage = new MimeMessage(session);
                    //邮件发送人
                    mimeMessage.setFrom(new InternetAddress(recipient));
        
                    //邮件接收人
                    mimeMessage.setRecipient(Message.RecipientType.TO,new InternetAddress(user.getMail()));
        
                    //邮件标题
                    mimeMessage.setSubject("网站注册成功");
        
                    //邮件内容
                    mimeMessage.setContent("网站注册成功，密码为"+user.getPassword()+"，请妥善保管密码","text/html;charset=UTF-8");
        
                    //发送邮件
                    transport.sendMessage(mimeMessage,mimeMessage.getAllRecipients());
        
                    transport.close();
        
                }catch (Exception e){
              
                    e.printStackTrace();
                }
        
            }
        
        }
4.  **register.jsp**
    
        <%@ page contentType="text/html;charset=UTF-8" language="java" %>
        <html>
        <head>
            <title>注册页面</title>
        </head>
        <body>
        
        <form action="${pageContext.request.contextPath}/a.do" method="post">
            <p>用户名：<input type="text" name="username" required></p>
            <p>密码：<input type="password" name="password" required></p>
            <p>邮箱：<input type="email" name="email" required></p>
            <p><input type="submit" value="提交"></p>
        </form>
        </body>
        </html>
5.  **msg.jsp**
    
        <%@ page contentType="text/html;charset=UTF-8" language="java" %>
        <html>
        <head>
            <title>Title</title>
        </head>
        <body>
        ${msg}
        </body>
        </html>
6.  **web.xml**
    
        <?xml version="1.0" encoding="UTF-8"?>
        <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
                 version="4.0">
            <servlet>
                <servlet-name>Servlet</servlet-name>
                <servlet-class>org.westos.mail.Servlet</servlet-class>
            </servlet>
        
            <servlet-mapping>
                <servlet-name>Servlet</servlet-name>
                <url-pattern>/a.do</url-pattern>
            </servlet-mapping>
        </web-app>

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