我正在尝试获取邮件的嵌入式图像，为此，我具有以下代码：
protected void setCidAttachments(Message message, MensajeEmail mensajeEmail) {
try {
MimeMultipart mimeMultipart = (MimeMultipart) message.getDataHandler().getContent();
for (int k = 0; k < mimeMultipart.getCount(); k++) {
MimeBodyPart part = (MimeBodyPart) mimeMultipart.getBodyPart(k);
processPart(part, mensajeEmail);
}
}
catch (Exception e) {
log.error("Error obtendo adxuntos con cid", e);
}
}
private void processPart (BodyPart part, MensajeEmail mensajeEmail) throws MessagingException, IOException {
String type = getContentType(part);
StringBuilder content = new StringBuilder(mensajeEmail.getContenido());
if (isImage(type) && part.getDataHandler() != null && part.getDataHandler().getContent() != null) {
if (part.getDataHandler().getContent() instanceof MimeMultipart) {
MimeMultipart p = (MimeMultipart) part.getDataHandler().getContent();
for (int i = 0; i < p.getCount(); i++) {
BodyPart subpart = p.getBodyPart(i != p.getCount() - 1 ? i + 1 : i);
processPart(subpart, mensajeEmail);
}
} else {
mensajeEmail.setContenido(getInlineImage(part, content));
}
}
}
private String getInlineImage (BodyPart part, StringBuilder content) throws MessagingException, IOException {
Base64 decoder64 = new Base64();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
// Get type
String type = getContentType(part);
// Get Content-ID
String contentId = getContentId(part);
// Replace
if (contentId.length() > 0) {
part.getDataHandler().writeTo(bos);
int start = content.indexOf("src=\"cid:" + contentId + "\"") + 5;
if (start > 4) {
int length = contentId.length() + 4;
content.replace(start, start + length, "data:" + (isImage(type) ? type : "image/png;") + " base64," + decoder64.encodeToString(bos.toByteArray()));
}
}
bos.close();
return content.toString();
}
private String getContentId (BodyPart part) throws MessagingException {
Enumeration headers = part.getAllHeaders();
while (headers.hasMoreElements()) {
Header header = (Header)headers.nextElement();
if (header.getName().equalsIgnoreCase("Content-ID"))
return cleanContentId(header.getValue());
}
return "";
}
private String getContentType (BodyPart part) throws MessagingException {
return part.getContentType().split(" ")[0];
}
private boolean isImage (String mime) {
return !mime.equals("text/html;") && !mime.equals("text/plain;");
}
private String cleanContentId (String contentId) {
if (contentId.charAt(0) == '<') contentId = contentId.substring(1, contentId.length() - 1);
return contentId;
}
当我发送PNG图像时，这工作得很好（这使我认为我的代码确实正确）。但是，当我尝试发送JPG图像时，出现以下异常：
javax.activation.UnsupportedDataTypeException: Unknown image type image/jpeg; name=sony-car-796x418.jpg
at org.apache.geronimo.activation.handlers.AbstractImageHandler.getContent(AbstractImageHandler.java:57)
at javax.activation.DataSourceDataContentHandler.getContent(DataHandler.java:795)
at javax.activation.DataHandler.getContent(DataHandler.java:542)
at es.enxenio.fcpw.plinper.daemons.email.AbstractProtocoloObtencionEmail.processPart(AbstractProtocoloObtencionEmail.java:378)
...
该框架真的无法使用JPG图片吗？有什么办法可以解决这个问题？
编辑：Gmail甚至都不让我发送JPG图像，因此它可能不是邮件图像的一种非常常见的格式，这使我认为可能未得到广泛实施，这可能是Java似乎无法实现的原因使用它
我发现了问题。此行
if (isImage(type) && part.getDataHandler() != null && part.getDataHandler().getContent()
不应该检查类型是否为图像，而是是否为多部分。否则，我们可能会将jpg图像作为多部分处理。出于某种原因，png图像对此并不介意，这就是它起作用的原因。这是代码的更改部分：
protected void setCidAttachments(Message message, MensajeEmail mensajeEmail) {
try {
processPart(message, mensajeEmail);
}
catch (Exception e) {
log.error("Error obtendo adxuntos con cid", e);
}
}
private void processPart(Part part, MensajeEmail mensajeEmail) throws MessagingException, IOException {
String type = getContentType(part);
StringBuilder content = new StringBuilder(mensajeEmail.getContenido());
if (isMultipart(type) && part.getDataHandler() != null && part.getDataHandler().getContent() != null && part.getDataHandler().getContent() instanceof MimeMultipart) {
MimeMultipart multipart = (MimeMultipart) part.getDataHandler().getContent();
for (int i = 0; i < multipart.getCount(); i++) {
BodyPart subpart = multipart.getBodyPart(i);
processPart(subpart, mensajeEmail);
}
}
else {
mensajeEmail.setContenido(getInlineImage(part, content));
}
}
private boolean isMultipart(String mime) {
return (Pattern.matches("multipart/.*", mime));
}