pom.xml

<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>javax.mail</artifactId>
    <version>1.5.6</version>
</dependency>

MailSenderInfo.java

import com.sun.mail.util.MailSSLSocketFactory;

import java.security.GeneralSecurityException;
 
import java.util.Properties;

public class MailSenderInfo {

    // 傳送郵件的伺服器的IP和埠
    private String mailServerHost;
    private String mailServerPort = "25";
    // 郵件傳送者的地址
    private String fromAddress;
    // 郵件接收者的地址
    private String toAddress;

    private String password;
    // 是否需要身份驗證
    private
 
 boolean validate = false;
    // 郵件主題
    private String subject;
    // 郵件的文字內容
    private String content;
    // 郵件附件的檔名
    private String[] attachFileNames;
    //郵件發件人暱稱
    private String nick;

    private boolean ssl;

    public String getNick() {
        return nick;
    }

    public boolean isSsl() {
        
 
return ssl;
    }

    public void setSsl(boolean ssl) {
        this.ssl = ssl;
    }

    public void setNick(String nick) {
        this.nick = nick;
    }

    private String httpServer;
    private MailType type = MailType.TEXT;//html or text;

    enum MailType {
        TEXT, HTML;
    }

    /** */
    /**
     * 獲得郵件會話屬性
     */
    public Properties getProperties() {
        Properties p = new Properties();
        p.put("mail.smtp.host", this.mailServerHost);
        p.put("mail.smtp.port", this.mailServerPort);
        p.put("mail.smtp.auth", validate ? "true" : "false");
        if (ssl) {
            try {
                MailSSLSocketFactory sf = new MailSSLSocketFactory();
                sf.setTrustAllHosts(true);
                p.put("mail.smtp.ssl.enable", "true");
                p.put("mail.smtp.ssl.socketFactory", sf);
            } catch (GeneralSecurityException e) {
            }

        }
        return p;
    }

    public String getMailServerHost() {
        return mailServerHost;
    }

    public void setMailServerHost(String mailServerHost) {
        this.mailServerHost = mailServerHost;
    }

    public String getMailServerPort() {
        return mailServerPort;
    }

    public void setMailServerPort(String mailServerPort) {
        this.mailServerPort = mailServerPort;
    }

    public boolean isValidate() {
        return validate;
    }

    public void setValidate(boolean validate) {
        this.validate = validate;
    }

    public String[] getAttachFileNames() {
        return attachFileNames;
    }

    public void setAttachFileNames(String[] fileNames) {
        this.attachFileNames = fileNames;
    }

    public String getFromAddress() {
        return fromAddress;
    }

    public void setFromAddress(String fromAddress) {
        this.fromAddress = fromAddress;
    }

    public String getPassword() {
        return password;
    }

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

    public String getToAddress() {
        return toAddress;
    }

    public void setToAddress(String toAddress) {
        this.toAddress = toAddress;
    }


    public String getSubject() {
        return subject;
    }

    public void setSubject(String subject) {
        this.subject = subject;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String textContent) {
        this.content = textContent;
    }

    public String getHttpServer() {
        return httpServer;
    }

    public void setHttpServer(String httpServer) {
        this.httpServer = httpServer;
    }

    public MailType getType() {
        return type;
    }

    public void setType(MailType type) {
        this.type = type;
    }

    @Override
    public String toString() {
        return "MailSenderInfo [mailServerHost=" + mailServerHost + ", mailServerPort=" + mailServerPort
                + ", fromAddress=" + fromAddress + ", toAddress=" + toAddress + ", content=" + content + ", httpServer="
                + httpServer + ", type=" + type + "]";
    }


}

MyAuthenticator.java

import javax.mail.Authenticator;
import javax.mail.PasswordAuthentication;

public class MyAuthenticator extends Authenticator {

    String userName = null;
    String password = null;

    public MyAuthenticator() {
    }

    public MyAuthenticator(String username, String password) {
        this.userName = username;
        this.password = password;
    }

    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(userName, password);
    }
    
}

Test.java

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

/**
 * @author jiash
 * @since 2021/10/8
 */
public class Test {
    private static final String CHARSET = "UTF-8";

    public static boolean sendTextMail(MailSenderInfo mailInfo) {
        MyAuthenticator authenticator = null;
        Properties pro = mailInfo.getProperties();
        if (mailInfo.isValidate()) {
            // 如果需要身份認證，則建立一個密碼驗證器
            authenticator = new MyAuthenticator(mailInfo.getFromAddress(),
                    mailInfo.getPassword());
        }
        Session sendMailSession = Session.getInstance(pro, authenticator);
        try {
            // 根據session建立一個郵件通知
            MimeMessage mailMessage = new MimeMessage(sendMailSession);
            // 建立郵件傳送者地址
            Address from = new InternetAddress(mailInfo.getFromAddress());
            if (mailInfo.getNick() != null && !"".equals(mailInfo.getNick())) {
                String nickName;
                try {
                    nickName = javax.mail.internet.MimeUtility.encodeText(mailInfo.getNick());
                    mailMessage.setFrom(new InternetAddress(nickName + " <" + from + ">"));
                } catch (Exception e) {
                }
            } else {
                // 設定郵件通知的傳送者
                mailMessage.setFrom(from);
            }


            // 建立郵件的接收者地址，並設定到郵件通知中
            Address to = new InternetAddress(mailInfo.getToAddress());
            mailMessage.setRecipient(Message.RecipientType.TO, to);
            // 設定郵件通知的主題
            mailMessage.setSubject(mailInfo.getSubject(), CHARSET);
            // 設定郵件通知傳送的時間
            mailMessage.setSentDate(new Date());

            Multipart mp = new MimeMultipart();
            MimeBodyPart mbpContent = new MimeBodyPart();
            mbpContent.setContent(mailInfo.getContent(),
                    "text/plain;charset=utf-8");
            mp.addBodyPart(mbpContent);

            if (mailInfo.getAttachFileNames() != null) {

                for (String fileName : mailInfo.getAttachFileNames()) {
                    MimeBodyPart mbpFile = new MimeBodyPart();
                    FileDataSource fds = new FileDataSource(fileName);
                    mbpFile.setDataHandler(new DataHandler(fds));
                    // 解決預發環境的傳送郵件時附件的標題亂碼問題
                    mbpFile.setFileName(MimeUtility.encodeText(fds.getName()));
                    mp.addBodyPart(mbpFile);
                }
            }

            // 設定郵件通知的主要內容
            mailMessage.setContent(mp);
            // 傳送郵件
            Transport.send(mailMessage);
            return true;
        } catch (Exception ex) {
        }
        return false;
    }


    /**
     * 以HTML格式傳送郵件
     *
     * @param mailInfo 待發送的郵件資訊
     */
    public static boolean sendHtmlMail(MailSenderInfo mailInfo) {
        // 判斷是否需要身份認證
        MyAuthenticator authenticator = null;
        Properties pro = mailInfo.getProperties();
        // 如果需要身份認證，則建立一個密碼驗證器
        if (mailInfo.isValidate()) {
            authenticator = new MyAuthenticator(mailInfo.getFromAddress(),
                    mailInfo.getPassword());
        }
        // 根據郵件會話屬性和密碼驗證器構造一個傳送郵件的session
        Session sendMailSession = Session.getInstance(pro, authenticator);
        try {
            // 根據session建立一個郵件通知
            MimeMessage mailMessage = new MimeMessage(sendMailSession);
            // 建立郵件傳送者地址
            Address from = new InternetAddress(mailInfo.getFromAddress());
            // 設定郵件通知的傳送者
            mailMessage.setFrom(from);
            // 建立郵件的接收者地址，並設定到郵件通知中
            Address to = new InternetAddress(mailInfo.getToAddress());
            // Message.RecipientType.TO屬性表示接收者的型別為TO
            mailMessage.setRecipient(Message.RecipientType.TO, to);
            // 設定郵件通知的主題
            mailMessage.setSubject(mailInfo.getSubject(), CHARSET);
            // 設定郵件通知傳送的時間
            mailMessage.setSentDate(new Date());
            // MiniMultipart類是一個容器類，包含MimeBodyPart型別的物件
            Multipart mainPart = new MimeMultipart();

            if (mailInfo.getAttachFileNames() != null) {
                /*MimeBodyPart mbpContent = new MimeBodyPart();
                mbpContent.setContent(mailInfo.getContent(),
                        "text/plain;charset=utf-8");
                mainPart.addBodyPart(mbpContent);*/
                for (String fileName : mailInfo.getAttachFileNames()) {
                    MimeBodyPart mbpFile = new MimeBodyPart();
                    FileDataSource fds = new FileDataSource(fileName);
                    mbpFile.setDataHandler(new DataHandler(fds));
                    // 解決預發環境的傳送郵件時附件的標題亂碼問題
                    mbpFile.setFileName(MimeUtility.encodeText(fds.getName()));
                    mainPart.addBodyPart(mbpFile);
                }
            }

            // 建立一個包含HTML內容的MimeBodyPart
            BodyPart html = new MimeBodyPart();
            // 設定HTML內容
            html.setContent(mailInfo.getContent(), "text/html; charset=utf-8");
            mainPart.addBodyPart(html);
            // 建立一個包含圖表的的MimeBodyPart
            // 將MiniMultipart物件設定為郵件內容
            mailMessage.setContent(mainPart);
            // 傳送郵件
            Transport.send(mailMessage);
            return true;
        } catch (Exception ex) {
        }
        return false;
    }


    public static void main(String[] args) {
        MailSenderInfo mailInfo = new MailSenderInfo();

        mailInfo.setMailServerHost("smtp.sina.net");
        mailInfo.setPassword("解密後的明文密碼xxxxx");
        mailInfo.setFromAddress("[email protected]");
        mailInfo.setMailServerPort("25");
        mailInfo.setValidate(true);

        mailInfo.setToAddress("[email protected]");
        mailInfo.setSubject("測試主題");
        mailInfo.setContent("測試一下");
        sendTextMail(mailInfo);
    }
}

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