SpringBoot集成实现各种邮件发送

JavaMail是提供给开发者处理电子邮件相关的编程接口。它是Sun发布的用来处理email的API。正常我们会用JavaMail相关api来写发送邮件的相关代码。

使用过Spring的众多开发者都知道Spring提供了非常好用的 JavaMailSender接口实现邮件发送。在Spring BootStarter模块中也为此提供了自动化配置。

SpringBoot集成邮件引入依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

底层是使用MailMessage接口

public interface MailMessage {
    void setFrom(String var1) throws MailParseException;

    void setReplyTo(String var1) throws MailParseException;

    void setTo(String var1) throws MailParseException;

    void setTo(String... var1) throws MailParseException;

    void setCc(String var1) throws MailParseException;

    void setCc(String... var1) throws MailParseException;

    void setBcc(String var1) throws MailParseException;

    void setBcc(String... var1) throws MailParseException;

    void setSentDate(Date var1) throws MailParseException;

    void setSubject(String var1) throws MailParseException;

    void setText(String var1) throws MailParseException;
}

MailMessage有两个实现类,分别是SimpleMailMessageMimeMailMessage

SimpleMailMessage源码

public class SimpleMailMessage implements MailMessage, Serializable {
    @Nullable
    private String from;
    @Nullable
    private String replyTo;
    @Nullable
    private String[] to;
    @Nullable
    private String[] cc;
    @Nullable
    private String[] bcc;
    @Nullable
    private Date sentDate;
    @Nullable
    private String subject;
    @Nullable
    private String text;

    public SimpleMailMessage() {
    }

    public SimpleMailMessage(SimpleMailMessage original) {
        Assert.notNull(original, "'original' message argument must not be null");
        this.from = original.getFrom();
        this.replyTo = original.getReplyTo();
        this.to = copyOrNull(original.getTo());
        this.cc = copyOrNull(original.getCc());
        this.bcc = copyOrNull(original.getBcc());
        this.sentDate = original.getSentDate();
        this.subject = original.getSubject();
        this.text = original.getText();
    }

    public void setFrom(String from) {
        this.from = from;
    }

    @Nullable
    public String getFrom() {
        return this.from;
    }

    public void setReplyTo(String replyTo) {
        this.replyTo = replyTo;
    }

    @Nullable
    public String getReplyTo() {
        return this.replyTo;
    }

    public void setTo(String to) {
        this.to = new String[]{to};
    }

    public void setTo(String... to) {
        this.to = to;
    }

    @Nullable
    public String[] getTo() {
        return this.to;
    }

    public void setCc(String cc) {
        this.cc = new String[]{cc};
    }

    public void setCc(String... cc) {
        this.cc = cc;
    }

    @Nullable
    public String[] getCc() {
        return this.cc;
    }

    public void setBcc(String bcc) {
        this.bcc = new String[]{bcc};
    }

    public void setBcc(String... bcc) {
        this.bcc = bcc;
    }

    @Nullable
    public String[] getBcc() {
        return this.bcc;
    }

    public void setSentDate(Date sentDate) {
        this.sentDate = sentDate;
    }

    @Nullable
    public Date getSentDate() {
        return this.sentDate;
    }

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

    @Nullable
    public String getSubject() {
        return this.subject;
    }

    public void setText(String text) {
        this.text = text;
    }

    @Nullable
    public String getText() {
        return this.text;
    }

    public void copyTo(MailMessage target) {
        Assert.notNull(target, "'target' MailMessage must not be null");
        if (this.getFrom() != null) {
            target.setFrom(this.getFrom());
        }

        if (this.getReplyTo() != null) {
            target.setReplyTo(this.getReplyTo());
        }

        if (this.getTo() != null) {
            target.setTo(copy(this.getTo()));
        }

        if (this.getCc() != null) {
            target.setCc(copy(this.getCc()));
        }

        if (this.getBcc() != null) {
            target.setBcc(copy(this.getBcc()));
        }

        if (this.getSentDate() != null) {
            target.setSentDate(this.getSentDate());
        }

        if (this.getSubject() != null) {
            target.setSubject(this.getSubject());
        }

        if (this.getText() != null) {
            target.setText(this.getText());
        }

    }

    public boolean equals(Object other) {
        if (this == other) {
            return true;
        } else if (!(other instanceof SimpleMailMessage)) {
            return false;
        } else {
            SimpleMailMessage otherMessage = (SimpleMailMessage)other;
            return ObjectUtils.nullSafeEquals(this.from, otherMessage.from) && ObjectUtils.nullSafeEquals(this.replyTo, otherMessage.replyTo) && ObjectUtils.nullSafeEquals(this.to, otherMessage.to) && ObjectUtils.nullSafeEquals(this.cc, otherMessage.cc) && ObjectUtils.nullSafeEquals(this.bcc, otherMessage.bcc) && ObjectUtils.nullSafeEquals(this.sentDate, otherMessage.sentDate) && ObjectUtils.nullSafeEquals(this.subject, otherMessage.subject) && ObjectUtils.nullSafeEquals(this.text, otherMessage.text);
        }
    }

    public int hashCode() {
        int hashCode = ObjectUtils.nullSafeHashCode(this.from);
        hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.replyTo);
        hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.to);
        hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.cc);
        hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.bcc);
        hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.sentDate);
        hashCode = 29 * hashCode + ObjectUtils.nullSafeHashCode(this.subject);
        return hashCode;
    }

    public String toString() {
        StringBuilder sb = new StringBuilder("SimpleMailMessage: ");
        sb.append("from=").append(this.from).append("; ");
        sb.append("replyTo=").append(this.replyTo).append("; ");
        sb.append("to=").append(StringUtils.arrayToCommaDelimitedString(this.to)).append("; ");
        sb.append("cc=").append(StringUtils.arrayToCommaDelimitedString(this.cc)).append("; ");
        sb.append("bcc=").append(StringUtils.arrayToCommaDelimitedString(this.bcc)).append("; ");
        sb.append("sentDate=").append(this.sentDate).append("; ");
        sb.append("subject=").append(this.subject).append("; ");
        sb.append("text=").append(this.text);
        return sb.toString();
    }

    @Nullable
    private static String[] copyOrNull(@Nullable String[] state) {
        return state == null ? null : copy(state);
    }

    private static String[] copy(String[] state) {
        String[] copy = new String[state.length];
        System.arraycopy(state, 0, copy, 0, state.length);
        return copy;
    }
}

MimeMailMessage源码

public class MimeMailMessage implements MailMessage {
    private final MimeMessageHelper helper;

    public MimeMailMessage(MimeMessageHelper mimeMessageHelper) {
        this.helper = mimeMessageHelper;
    }

    public MimeMailMessage(MimeMessage mimeMessage) {
        this.helper = new MimeMessageHelper(mimeMessage);
    }

    public final MimeMessageHelper getMimeMessageHelper() {
        return this.helper;
    }

    public final MimeMessage getMimeMessage() {
        return this.helper.getMimeMessage();
    }

    public void setFrom(String from) throws MailParseException {
        try {
            this.helper.setFrom(from);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setReplyTo(String replyTo) throws MailParseException {
        try {
            this.helper.setReplyTo(replyTo);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setTo(String to) throws MailParseException {
        try {
            this.helper.setTo(to);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setTo(String... to) throws MailParseException {
        try {
            this.helper.setTo(to);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setCc(String cc) throws MailParseException {
        try {
            this.helper.setCc(cc);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setCc(String... cc) throws MailParseException {
        try {
            this.helper.setCc(cc);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setBcc(String bcc) throws MailParseException {
        try {
            this.helper.setBcc(bcc);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setBcc(String... bcc) throws MailParseException {
        try {
            this.helper.setBcc(bcc);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setSentDate(Date sentDate) throws MailParseException {
        try {
            this.helper.setSentDate(sentDate);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setSubject(String subject) throws MailParseException {
        try {
            this.helper.setSubject(subject);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }

    public void setText(String text) throws MailParseException {
        try {
            this.helper.setText(text);
        } catch (MessagingException var3) {
            throw new MailParseException(var3);
        }
    }
}

参数说明:
subject :邮件主题
content :邮件主题内容
from:发件人Email地址
to:收件人Email地址

MimeMessageHelper是处理JavaMail比较顺手的组件之一,可以让你摆脱繁复的JavaMail API
可用于发送附件和嵌入式资源(inline resources),允许添加附件和内嵌资源(inline resources)。
内嵌资源可能是你在信件中希望使用的图像或样式表,但是又不想把它们作为附件。

public class MimeMessageHelper {
    public static final int MULTIPART_MODE_NO = 0;
    public static final int MULTIPART_MODE_MIXED = 1;
    public static final int MULTIPART_MODE_RELATED = 2;
    public static final int MULTIPART_MODE_MIXED_RELATED = 3;
    private static final String MULTIPART_SUBTYPE_MIXED = "mixed";
    private static final String MULTIPART_SUBTYPE_RELATED = "related";
    private static final String MULTIPART_SUBTYPE_ALTERNATIVE = "alternative";
    private static final String CONTENT_TYPE_ALTERNATIVE = "text/alternative";
    private static final String CONTENT_TYPE_HTML = "text/html";
    private static final String CONTENT_TYPE_CHARSET_SUFFIX = ";charset=";
    private static final String HEADER_PRIORITY = "X-Priority";
    private static final String HEADER_CONTENT_ID = "Content-ID";
    private final MimeMessage mimeMessage;
    @Nullable
    private MimeMultipart rootMimeMultipart;
    @Nullable
    private MimeMultipart mimeMultipart;
    @Nullable
    private final String encoding;
    private FileTypeMap fileTypeMap;
    private boolean validateAddresses;

    public MimeMessageHelper(MimeMessage mimeMessage) {
        this(mimeMessage, (String)null);
    }

    public MimeMessageHelper(MimeMessage mimeMessage, @Nullable String encoding) {
        this.validateAddresses = false;
        this.mimeMessage = mimeMessage;
        this.encoding = encoding != null ? encoding : this.getDefaultEncoding(mimeMessage);
        this.fileTypeMap = this.getDefaultFileTypeMap(mimeMessage);
    }

    public MimeMessageHelper(MimeMessage mimeMessage, boolean multipart) throws MessagingException {
        this(mimeMessage, multipart, (String)null);
    }

    public MimeMessageHelper(MimeMessage mimeMessage, boolean multipart, @Nullable String encoding) throws MessagingException {
        this(mimeMessage, multipart ? 3 : 0, encoding);
    }

    public MimeMessageHelper(MimeMessage mimeMessage, int multipartMode) throws MessagingException {
        this(mimeMessage, multipartMode, (String)null);
    }

    public MimeMessageHelper(MimeMessage mimeMessage, int multipartMode, @Nullable String encoding) throws MessagingException {
        this.validateAddresses = false;
        this.mimeMessage = mimeMessage;
        this.createMimeMultiparts(mimeMessage, multipartMode);
        this.encoding = encoding != null ? encoding : this.getDefaultEncoding(mimeMessage);
        this.fileTypeMap = this.getDefaultFileTypeMap(mimeMessage);
    }

    public final MimeMessage getMimeMessage() {
        return this.mimeMessage;
    }

    protected void createMimeMultiparts(MimeMessage mimeMessage, int multipartMode) throws MessagingException {
        switch(multipartMode) {
        case 0:
            this.setMimeMultiparts((MimeMultipart)null, (MimeMultipart)null);
            break;
        case 1:
            MimeMultipart mixedMultipart = new MimeMultipart("mixed");
            mimeMessage.setContent(mixedMultipart);
            this.setMimeMultiparts(mixedMultipart, mixedMultipart);
            break;
        case 2:
            MimeMultipart relatedMultipart = new MimeMultipart("related");
            mimeMessage.setContent(relatedMultipart);
            this.setMimeMultiparts(relatedMultipart, relatedMultipart);
            break;
        case 3:
            MimeMultipart rootMixedMultipart = new MimeMultipart("mixed");
            mimeMessage.setContent(rootMixedMultipart);
            MimeMultipart nestedRelatedMultipart = new MimeMultipart("related");
            MimeBodyPart relatedBodyPart = new MimeBodyPart();
            relatedBodyPart.setContent(nestedRelatedMultipart);
            rootMixedMultipart.addBodyPart(relatedBodyPart);
            this.setMimeMultiparts(rootMixedMultipart, nestedRelatedMultipart);
            break;
        default:
            throw new IllegalArgumentException("Only multipart modes MIXED_RELATED, RELATED and NO supported");
        }

    }

    protected final void setMimeMultiparts(@Nullable MimeMultipart root, @Nullable MimeMultipart main) {
        this.rootMimeMultipart = root;
        this.mimeMultipart = main;
    }

    public final boolean isMultipart() {
        return this.rootMimeMultipart != null;
    }

    public final MimeMultipart getRootMimeMultipart() throws IllegalStateException {
        if (this.rootMimeMultipart == null) {
            throw new IllegalStateException("Not in multipart mode - create an appropriate MimeMessageHelper via a constructor that takes a 'multipart' flag if you need to set alternative texts or add inline elements or attachments.");
        } else {
            return this.rootMimeMultipart;
        }
    }

    public final MimeMultipart getMimeMultipart() throws IllegalStateException {
        if (this.mimeMultipart == null) {
            throw new IllegalStateException("Not in multipart mode - create an appropriate MimeMessageHelper via a constructor that takes a 'multipart' flag if you need to set alternative texts or add inline elements or attachments.");
        } else {
            return this.mimeMultipart;
        }
    }

    @Nullable
    protected String getDefaultEncoding(MimeMessage mimeMessage) {
        return mimeMessage instanceof SmartMimeMessage ? ((SmartMimeMessage)mimeMessage).getDefaultEncoding() : null;
    }

    @Nullable
    public String getEncoding() {
        return this.encoding;
    }

    protected FileTypeMap getDefaultFileTypeMap(MimeMessage mimeMessage) {
        if (mimeMessage instanceof SmartMimeMessage) {
            FileTypeMap fileTypeMap = ((SmartMimeMessage)mimeMessage).getDefaultFileTypeMap();
            if (fileTypeMap != null) {
                return fileTypeMap;
            }
        }

        ConfigurableMimeFileTypeMap fileTypeMap = new ConfigurableMimeFileTypeMap();
        fileTypeMap.afterPropertiesSet();
        return fileTypeMap;
    }

    public void setFileTypeMap(@Nullable FileTypeMap fileTypeMap) {
        this.fileTypeMap = fileTypeMap != null ? fileTypeMap : this.getDefaultFileTypeMap(this.getMimeMessage());
    }

    public FileTypeMap getFileTypeMap() {
        return this.fileTypeMap;
    }

    public void setValidateAddresses(boolean validateAddresses) {
        this.validateAddresses = validateAddresses;
    }

    public boolean isValidateAddresses() {
        return this.validateAddresses;
    }

    protected void validateAddress(InternetAddress address) throws AddressException {
        if (this.isValidateAddresses()) {
            address.validate();
        }

    }

    protected void validateAddresses(InternetAddress[] addresses) throws AddressException {
        InternetAddress[] var2 = addresses;
        int var3 = addresses.length;

        for(int var4 = 0; var4 < var3; ++var4) {
            InternetAddress address = var2[var4];
            this.validateAddress(address);
        }

    }

    public void setFrom(InternetAddress from) throws MessagingException {
        Assert.notNull(from, "From address must not be null");
        this.validateAddress(from);
        this.mimeMessage.setFrom(from);
    }

    public void setFrom(String from) throws MessagingException {
        Assert.notNull(from, "From address must not be null");
        this.setFrom(this.parseAddress(from));
    }

    public void setFrom(String from, String personal) throws MessagingException, UnsupportedEncodingException {
        Assert.notNull(from, "From address must not be null");
        this.setFrom(this.getEncoding() != null ? new InternetAddress(from, personal, this.getEncoding()) : new InternetAddress(from, personal));
    }

    public void setReplyTo(InternetAddress replyTo) throws MessagingException {
        Assert.notNull(replyTo, "Reply-to address must not be null");
        this.validateAddress(replyTo);
        this.mimeMessage.setReplyTo(new InternetAddress[]{replyTo});
    }

    public void setReplyTo(String replyTo) throws MessagingException {
        Assert.notNull(replyTo, "Reply-to address must not be null");
        this.setReplyTo(this.parseAddress(replyTo));
    }

    public void setReplyTo(String replyTo, String personal) throws MessagingException, UnsupportedEncodingException {
        Assert.notNull(replyTo, "Reply-to address must not be null");
        InternetAddress replyToAddress = this.getEncoding() != null ? new InternetAddress(replyTo, personal, this.getEncoding()) : new InternetAddress(replyTo, personal);
        this.setReplyTo(replyToAddress);
    }

    public void setTo(InternetAddress to) throws MessagingException {
        Assert.notNull(to, "To address must not be null");
        this.validateAddress(to);
        this.mimeMessage.setRecipient(RecipientType.TO, to);
    }

    public void setTo(InternetAddress[] to) throws MessagingException {
        Assert.notNull(to, "To address array must not be null");
        this.validateAddresses(to);
        this.mimeMessage.setRecipients(RecipientType.TO, to);
    }

    public void setTo(String to) throws MessagingException {
        Assert.notNull(to, "To address must not be null");
        this.setTo(this.parseAddress(to));
    }

    public void setTo(String[] to) throws MessagingException {
        Assert.notNull(to, "To address array must not be null");
        InternetAddress[] addresses = new InternetAddress[to.length];

        for(int i = 0; i < to.length; ++i) {
            addresses[i] = this.parseAddress(to[i]);
        }

        this.setTo(addresses);
    }

    public void addTo(InternetAddress to) throws MessagingException {
        Assert.notNull(to, "To address must not be null");
        this.validateAddress(to);
        this.mimeMessage.addRecipient(RecipientType.TO, to);
    }

    public void addTo(String to) throws MessagingException {
        Assert.notNull(to, "To address must not be null");
        this.addTo(this.parseAddress(to));
    }

    public void addTo(String to, String personal) throws MessagingException, UnsupportedEncodingException {
        Assert.notNull(to, "To address must not be null");
        this.addTo(this.getEncoding() != null ? new InternetAddress(to, personal, this.getEncoding()) : new InternetAddress(to, personal));
    }

    public void setCc(InternetAddress cc) throws MessagingException {
        Assert.notNull(cc, "Cc address must not be null");
        this.validateAddress(cc);
        this.mimeMessage.setRecipient(RecipientType.CC, cc);
    }

    public void setCc(InternetAddress[] cc) throws MessagingException {
        Assert.notNull(cc, "Cc address array must not be null");
        this.validateAddresses(cc);
        this.mimeMessage.setRecipients(RecipientType.CC, cc);
    }

    public void setCc(String cc) throws MessagingException {
        Assert.notNull(cc, "Cc address must not be null");
        this.setCc(this.parseAddress(cc));
    }

    public void setCc(String[] cc) throws MessagingException {
        Assert.notNull(cc, "Cc address array must not be null");
        InternetAddress[] addresses = new InternetAddress[cc.length];

        for(int i = 0; i < cc.length; ++i) {
            addresses[i] = this.parseAddress(cc[i]);
        }

        this.setCc(addresses);
    }

    public void addCc(InternetAddress cc) throws MessagingException {
        Assert.notNull(cc, "Cc address must not be null");
        this.validateAddress(cc);
        this.mimeMessage.addRecipient(RecipientType.CC, cc);
    }

    public void addCc(String cc) throws MessagingException {
        Assert.notNull(cc, "Cc address must not be null");
        this.addCc(this.parseAddress(cc));
    }

    public void addCc(String cc, String personal) throws MessagingException, UnsupportedEncodingException {
        Assert.notNull(cc, "Cc address must not be null");
        this.addCc(this.getEncoding() != null ? new InternetAddress(cc, personal, this.getEncoding()) : new InternetAddress(cc, personal));
    }

    public void setBcc(InternetAddress bcc) throws MessagingException {
        Assert.notNull(bcc, "Bcc address must not be null");
        this.validateAddress(bcc);
        this.mimeMessage.setRecipient(RecipientType.BCC, bcc);
    }

    public void setBcc(InternetAddress[] bcc) throws MessagingException {
        Assert.notNull(bcc, "Bcc address array must not be null");
        this.validateAddresses(bcc);
        this.mimeMessage.setRecipients(RecipientType.BCC, bcc);
    }

    public void setBcc(String bcc) throws MessagingException {
        Assert.notNull(bcc, "Bcc address must not be null");
        this.setBcc(this.parseAddress(bcc));
    }

    public void setBcc(String[] bcc) throws MessagingException {
        Assert.notNull(bcc, "Bcc address array must not be null");
        InternetAddress[] addresses = new InternetAddress[bcc.length];

        for(int i = 0; i < bcc.length; ++i) {
            addresses[i] = this.parseAddress(bcc[i]);
        }

        this.setBcc(addresses);
    }

    public void addBcc(InternetAddress bcc) throws MessagingException {
        Assert.notNull(bcc, "Bcc address must not be null");
        this.validateAddress(bcc);
        this.mimeMessage.addRecipient(RecipientType.BCC, bcc);
    }

    public void addBcc(String bcc) throws MessagingException {
        Assert.notNull(bcc, "Bcc address must not be null");
        this.addBcc(this.parseAddress(bcc));
    }

    public void addBcc(String bcc, String personal) throws MessagingException, UnsupportedEncodingException {
        Assert.notNull(bcc, "Bcc address must not be null");
        this.addBcc(this.getEncoding() != null ? new InternetAddress(bcc, personal, this.getEncoding()) : new InternetAddress(bcc, personal));
    }

    private InternetAddress parseAddress(String address) throws MessagingException {
        InternetAddress[] parsed = InternetAddress.parse(address);
        if (parsed.length != 1) {
            throw new AddressException("Illegal address", address);
        } else {
            InternetAddress raw = parsed[0];

            try {
                return this.getEncoding() != null ? new InternetAddress(raw.getAddress(), raw.getPersonal(), this.getEncoding()) : raw;
            } catch (UnsupportedEncodingException var5) {
                throw new MessagingException("Failed to parse embedded personal name to correct encoding", var5);
            }
        }
    }

    public void setPriority(int priority) throws MessagingException {
        this.mimeMessage.setHeader("X-Priority", Integer.toString(priority));
    }

    public void setSentDate(Date sentDate) throws MessagingException {
        Assert.notNull(sentDate, "Sent date must not be null");
        this.mimeMessage.setSentDate(sentDate);
    }

    public void setSubject(String subject) throws MessagingException {
        Assert.notNull(subject, "Subject must not be null");
        if (this.getEncoding() != null) {
            this.mimeMessage.setSubject(subject, this.getEncoding());
        } else {
            this.mimeMessage.setSubject(subject);
        }

    }

    public void setText(String text) throws MessagingException {
        this.setText(text, false);
    }

    public void setText(String text, boolean html) throws MessagingException {
        Assert.notNull(text, "Text must not be null");
        Object partToUse;
        if (this.isMultipart()) {
            partToUse = this.getMainPart();
        } else {
            partToUse = this.mimeMessage;
        }

        if (html) {
            this.setHtmlTextToMimePart((MimePart)partToUse, text);
        } else {
            this.setPlainTextToMimePart((MimePart)partToUse, text);
        }

    }

    public void setText(String plainText, String htmlText) throws MessagingException {
        Assert.notNull(plainText, "Plain text must not be null");
        Assert.notNull(htmlText, "HTML text must not be null");
        MimeMultipart messageBody = new MimeMultipart("alternative");
        this.getMainPart().setContent(messageBody, "text/alternative");
        MimeBodyPart plainTextPart = new MimeBodyPart();
        this.setPlainTextToMimePart(plainTextPart, plainText);
        messageBody.addBodyPart(plainTextPart);
        MimeBodyPart htmlTextPart = new MimeBodyPart();
        this.setHtmlTextToMimePart(htmlTextPart, htmlText);
        messageBody.addBodyPart(htmlTextPart);
    }

    private MimeBodyPart getMainPart() throws MessagingException {
        MimeMultipart mimeMultipart = this.getMimeMultipart();
        MimeBodyPart bodyPart = null;

        for(int i = 0; i < mimeMultipart.getCount(); ++i) {
            BodyPart bp = mimeMultipart.getBodyPart(i);
            if (bp.getFileName() == null) {
                bodyPart = (MimeBodyPart)bp;
            }
        }

        if (bodyPart == null) {
            MimeBodyPart mimeBodyPart = new MimeBodyPart();
            mimeMultipart.addBodyPart(mimeBodyPart);
            bodyPart = mimeBodyPart;
        }

        return bodyPart;
    }

    private void setPlainTextToMimePart(MimePart mimePart, String text) throws MessagingException {
        if (this.getEncoding() != null) {
            mimePart.setText(text, this.getEncoding());
        } else {
            mimePart.setText(text);
        }

    }

    private void setHtmlTextToMimePart(MimePart mimePart, String text) throws MessagingException {
        if (this.getEncoding() != null) {
            mimePart.setContent(text, "text/html;charset=" + this.getEncoding());
        } else {
            mimePart.setContent(text, "text/html");
        }

    }

    public void addInline(String contentId, DataSource dataSource) throws MessagingException {
        Assert.notNull(contentId, "Content ID must not be null");
        Assert.notNull(dataSource, "DataSource must not be null");
        MimeBodyPart mimeBodyPart = new MimeBodyPart();
        mimeBodyPart.setDisposition("inline");
        mimeBodyPart.setHeader("Content-ID", "<" + contentId + ">");
        mimeBodyPart.setDataHandler(new DataHandler(dataSource));
        this.getMimeMultipart().addBodyPart(mimeBodyPart);
    }

    public void addInline(String contentId, File file) throws MessagingException {
        Assert.notNull(file, "File must not be null");
        FileDataSource dataSource = new FileDataSource(file);
        dataSource.setFileTypeMap(this.getFileTypeMap());
        this.addInline(contentId, (DataSource)dataSource);
    }

    public void addInline(String contentId, Resource resource) throws MessagingException {
        Assert.notNull(resource, "Resource must not be null");
        String contentType = this.getFileTypeMap().getContentType(resource.getFilename());
        this.addInline(contentId, resource, contentType);
    }

    public void addInline(String contentId, InputStreamSource inputStreamSource, String contentType) throws MessagingException {
        Assert.notNull(inputStreamSource, "InputStreamSource must not be null");
        if (inputStreamSource instanceof Resource && ((Resource)inputStreamSource).isOpen()) {
            throw new IllegalArgumentException("Passed-in Resource contains an open stream: invalid argument. JavaMail requires an InputStreamSource that creates a fresh stream for every call.");
        } else {
            DataSource dataSource = this.createDataSource(inputStreamSource, contentType, "inline");
            this.addInline(contentId, dataSource);
        }
    }

    public void addAttachment(String attachmentFilename, DataSource dataSource) throws MessagingException {
        Assert.notNull(attachmentFilename, "Attachment filename must not be null");
        Assert.notNull(dataSource, "DataSource must not be null");

        try {
            MimeBodyPart mimeBodyPart = new MimeBodyPart();
            mimeBodyPart.setDisposition("attachment");
            mimeBodyPart.setFileName(MimeUtility.encodeText(attachmentFilename));
            mimeBodyPart.setDataHandler(new DataHandler(dataSource));
            this.getRootMimeMultipart().addBodyPart(mimeBodyPart);
        } catch (UnsupportedEncodingException var4) {
            throw new MessagingException("Failed to encode attachment filename", var4);
        }
    }

    public void addAttachment(String attachmentFilename, File file) throws MessagingException {
        Assert.notNull(file, "File must not be null");
        FileDataSource dataSource = new FileDataSource(file);
        dataSource.setFileTypeMap(this.getFileTypeMap());
        this.addAttachment(attachmentFilename, (DataSource)dataSource);
    }

    public void addAttachment(String attachmentFilename, InputStreamSource inputStreamSource) throws MessagingException {
        String contentType = this.getFileTypeMap().getContentType(attachmentFilename);
        this.addAttachment(attachmentFilename, inputStreamSource, contentType);
    }

    public void addAttachment(String attachmentFilename, InputStreamSource inputStreamSource, String contentType) throws MessagingException {
        Assert.notNull(inputStreamSource, "InputStreamSource must not be null");
        if (inputStreamSource instanceof Resource && ((Resource)inputStreamSource).isOpen()) {
            throw new IllegalArgumentException("Passed-in Resource contains an open stream: invalid argument. JavaMail requires an InputStreamSource that creates a fresh stream for every call.");
        } else {
            DataSource dataSource = this.createDataSource(inputStreamSource, contentType, attachmentFilename);
            this.addAttachment(attachmentFilename, dataSource);
        }
    }

    protected DataSource createDataSource(final InputStreamSource inputStreamSource, final String contentType, final String name) {
        return new DataSource() {
            public InputStream getInputStream() throws IOException {
                return inputStreamSource.getInputStream();
            }

            public OutputStream getOutputStream() {
                throw new UnsupportedOperationException("Read-only javax.activation.DataSource");
            }

            public String getContentType() {
                return contentType;
            }

            public String getName() {
                return name;
            }
        };
    }
}

邮件发送接口主要使用JavaMailSender

JavaMailSender接口源码

public interface JavaMailSender extends MailSender {
    MimeMessage createMimeMessage();

    MimeMessage createMimeMessage(InputStream var1) throws MailException;

    void send(MimeMessage var1) throws MailException;

    void send(MimeMessage... var1) throws MailException;

    void send(MimeMessagePreparator var1) throws MailException;

    void send(MimeMessagePreparator... var1) throws MailException;
}

JavaMailSender实现类为JavaMailSenderImpl,主要看邮件发送方法

JavaMailSenderImpl核心源码

public class JavaMailSenderImpl implements JavaMailSender {
    public void send(SimpleMailMessage simpleMessage) throws MailException {
        this.send(simpleMessage);
    }
    public void send(SimpleMailMessage... simpleMessages) throws MailException {
        List<MimeMessage> mimeMessages = new ArrayList(simpleMessages.length);
        SimpleMailMessage[] var3 = simpleMessages;
        int var4 = simpleMessages.length;

        for(int var5 = 0; var5 < var4; ++var5) {
            SimpleMailMessage simpleMessage = var3[var5];
            MimeMailMessage message = new MimeMailMessage(this.createMimeMessage());
            simpleMessage.copyTo(message);
            mimeMessages.add(message.getMimeMessage());
        }

        this.doSend((MimeMessage[])mimeMessages.toArray(new MimeMessage[0]), simpleMessages);
    }
    public void send(MimeMessage mimeMessage) throws MailException {
        this.send(mimeMessage);
    }

    public void send(MimeMessage... mimeMessages) throws MailException {
        this.doSend(mimeMessages, (Object[])null);
    }

    public void send(MimeMessagePreparator mimeMessagePreparator) throws MailException {
        this.send(mimeMessagePreparator);
    }

    public void send(MimeMessagePreparator... mimeMessagePreparators) throws MailException {
        try {
            List<MimeMessage> mimeMessages = new ArrayList(mimeMessagePreparators.length);
            MimeMessagePreparator[] var3 = mimeMessagePreparators;
            int var4 = mimeMessagePreparators.length;

            for(int var5 = 0; var5 < var4; ++var5) {
                MimeMessagePreparator preparator = var3[var5];
                MimeMessage mimeMessage = this.createMimeMessage();
                preparator.prepare(mimeMessage);
                mimeMessages.add(mimeMessage);
            }

            this.send((MimeMessage[])mimeMessages.toArray(new MimeMessage[0]));
        } catch (MailException var8) {
            throw var8;
        } catch (MessagingException var9) {
            throw new MailParseException(var9);
        } catch (Exception var10) {
            throw new MailPreparationException(var10);
        }
    }
    public MimeMessage createMimeMessage() {
        return new SmartMimeMessage(this.getSession(), this.getDefaultEncoding(), this.getDefaultFileTypeMap());
    }

    public MimeMessage createMimeMessage(InputStream contentStream) throws MailException {
        try {
            return new MimeMessage(this.getSession(), contentStream);
        } catch (Exception var3) {
            throw new MailParseException("Could not parse raw MIME content", var3);
        }
    }
    ......
}

SpringBoot实现邮件发送

YML配置

spring:
  mail:
    host: smtp.qq.com
    username: 发送者邮箱
    password: 邮箱授权码
    default-encoding: UTF-8

spring.mail.host为邮箱服务商的smtp地址
spring.mail.username:发送者邮箱
spring.mail.password邮箱服务商授权码

发送方必须要开启smtp,获取到的授权码,QQ邮箱获取授权码方法如下:
https://service.mail.qq.com/cgi-bin/help?subtype=1&&no=1001256&&id=28

使用SimpleMailMessage,设置发件人邮箱,收件人邮箱,主题和正文。

1.普通文本邮件发送

@Service
public class MailService {
    @Value("${spring.mail.username}")
    private  String from;
    @Autowired
    JavaMailSender javaMailSender;

    public void sendSimpleMail(String to,String subject,String content){
        SimpleMailMessage simpleMailMessage=new SimpleMailMessage();
        simpleMailMessage.setFrom(from);
        simpleMailMessage.setTo(to);
        simpleMailMessage.setSubject(subject);
        simpleMailMessage.setText(content);
        javaMailSender.send(simpleMailMessage);
    }
}
单元测试
@Autowired
MailService mailService;
@Test
public void test() throws MessagingException {
        mailService.sendSimpleMail("邮箱","主题","测试内容");
}
测试结果
image.png

MimeMessages为复杂邮件模板,支持文本、附件、HTML、图片等。

2.发送HTML邮件

创建MimeMessageHelper对象,处理MimeMessage的辅助类。

@Service
public class MailService {
    @Value("${spring.mail.username}")
    private  String from;
    @Autowired
    JavaMailSender javaMailSender;

    public void sendHtmlMail(String to,String subject,String content) throws MessagingException {
        MimeMessage mimeMessage=javaMailSender.createMimeMessage();
        MimeMessageHelper mimeMessageHelper=new MimeMessageHelper(mimeMessage,true);
        mimeMessageHelper.setFrom(from);
        mimeMessageHelper.setTo(to);
        mimeMessageHelper.setSubject(subject);
        mimeMessageHelper.setText(content,true);
        javaMailSender.send(mimeMessage);
    }
}

这里要注意的是发送HTML内容时需要设置html开启,默认为false

public void setText(String text, boolean html) throws MessagingException {
        Assert.notNull(text, "Text must not be null");
        Object partToUse;
        if (this.isMultipart()) {
            partToUse = this.getMainPart();
        } else {
            partToUse = this.mimeMessage;
        }

        if (html) {
            this.setHtmlTextToMimePart((MimePart)partToUse, text);
        } else {
            this.setPlainTextToMimePart((MimePart)partToUse, text);
        }

    }
单元测试
@Autowired
MailService mailService;
@Test
public void test() throws MessagingException {
       String content="<html>\n"+
        "<body>\n"+
        "<h3>hello world</h3>\n"+
        "</body>\n"+
        "</html>";
    mailService.sendHtmlMail("邮箱","主题",content);
}
测试结果
image.png

3.发送附件邮件

@Service
public class MailService {
    @Value("${spring.mail.username}")
    private  String from;
    @Autowired
    JavaMailSender javaMailSender;

   public void sendAttachmentMail(String to,String subject,String content,String filePath) throws MessagingException {
        MimeMessage mimeMessage=javaMailSender.createMimeMessage();
        MimeMessageHelper mimeMessageHelper=new MimeMessageHelper(mimeMessage,true);
        mimeMessageHelper.setFrom(from);
        mimeMessageHelper.setTo(to);
        mimeMessageHelper.setSubject(subject);
        mimeMessageHelper.setText(content,true);
        FileSystemResource fileSystemResource=new FileSystemResource(new File(filePath));
        String fileName=fileSystemResource.getFilename();
        mimeMessageHelper.addAttachment(fileName,fileSystemResource);
        javaMailSender.send(mimeMessage);
    }
}

需要开启邮件附件

public MimeMessageHelper(MimeMessage mimeMessage, boolean multipart) throws MessagingException {
        this(mimeMessage, multipart, (String)null);
    }

addAttachment()方法是添加附件

public void addAttachment(String attachmentFilename, InputStreamSource inputStreamSource) throws MessagingException {
        String contentType = this.getFileTypeMap().getContentType(attachmentFilename);
        this.addAttachment(attachmentFilename, inputStreamSource, contentType);
    }
单元测试
@Autowired
MailService mailService;
@Test
public void test() throws MessagingException {
        mailService.sendAttachmentMail("邮箱","主题","测试内容","E:\\文件名");
}
测试结果
image.png

推荐阅读更多精彩内容