[基本功能]发送邮件

• jar包：mail.jar & activation.jar
• 方法类

import java.util.Date;
import java.util.Properties;

import javax.activation.CommandMap;
import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.FileDataSource;
import javax.activation.MailcapCommandMap;
import javax.mail.Authenticator;
import javax.mail.BodyPart;
import javax.mail.Multipart;
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 javax.mail.internet.MimeUtility;

public class Mail extends Authenticator {

    private String _user;
    private String _pass;
    private String[] _to;
    private String _from;
    private String _subject;
    private String _body;
    private Multipart _multipart;

    private Mail() {
        this._multipart = new MimeMultipart();
        MailcapCommandMap commandMap = (MailcapCommandMap) CommandMap.getDefaultCommandMap();
        commandMap.addMailcap("text/html;;x-java-content-handler=com.sun.mail.handlers.text_html");
        commandMap.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");
        commandMap.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");
        commandMap.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");
        commandMap.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");
        CommandMap.setDefaultCommandMap(commandMap);
    }

    public Mail(String user, String pass) {
        this();
        this._user = user;
        this._pass = pass;
    }

    public void set_from(String _from) {
        this._from = _from;
    }

    public void set_to(String[] _to) {
        this._to = _to;
    }

    public void set_subject(String _subject) {
        this._subject = _subject;
    }

    public void set_body(String _body) {
        this._body = _body;
    }


    /* 添加附件 */
    public void addAttachment(String filename) throws Exception {
        BodyPart messageBodyPart = new MimeBodyPart();
        DataSource source = new FileDataSource(filename);
        DataHandler dataHandler = new DataHandler(source);
        messageBodyPart.setDataHandler(dataHandler);
        messageBodyPart.setFileName(MimeUtility.encodeText(dataHandler.getName())); // 解决中文附件名乱码
        _multipart.addBodyPart(messageBodyPart);
    }

    public boolean send() throws Exception {
        Properties props = _setProperties();
        if (!_user.equals("") && !_pass.equals("") && _to.length > 0 && !_from.equals("") && !_subject.equals("") && !_body.equals("")) {
            Authentication authentication = new Authentication(_user, _pass);
            Session session = Session.getDefaultInstance(props, authentication);
            session.setDebug(true);
            MimeMessage msg = new MimeMessage(session);
            msg.setFrom(new InternetAddress(_from));
            InternetAddress[] addressTo = new InternetAddress[_to.length];
            for (int i = 0; i < _to.length; i++) {
                addressTo[i] = new InternetAddress(_to[i]);
            }
            msg.setRecipients(MimeMessage.RecipientType.TO, addressTo);
            msg.setSubject(_subject);
            msg.setSentDate(new Date());
            BodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setText(_body);
            _multipart.addBodyPart(messageBodyPart);
            msg.setContent(_multipart);
            Transport.send(msg);
            return true;
        } else {
            return false;
        }
    }


    private Properties _setProperties() {
        Properties props = new Properties();
        props.put("mail.smtp.host", "---");
        props.put("mail.smtp.port", "---");
        props.put("mail.protocol", "smtp");
        props.put("mail.useSSL", "false");
        props.put("mail.smtp.auth", "true");
        return props;
    }


    @Override
    public PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication(_user, _pass);
    }


    /**
     * 公共方法：发送邮件
     */
    public static void send(String username, String password, String[] receivers, String title, String content, String... filePaths) {
        new Thread(() -> {
            Mail mail = new Mail(username, password);
            mail.set_to(receivers);
            mail.set_from(username);
            mail.set_subject(title);
            mail.set_body(content);
            try {
                for (String path : filePaths) {
                    mail.addAttachment(path);
                }
                if (mail.send()) {

                } else {
                    
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }).start();
    }
}

• 调用示例

public class MailTest {
    public static void main(String[] args) {
        String username = "[e-mail]";
        String password = "******";
        String[] recievers = {
                "[e-mail]",
                "[e-mail]",
        };
        String title = "title";
        String content = "content";

        Mail.send(username, password, recievers, title, content);
    }
}