com.sun.mail.pop3.POP3Message Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.mail.pop3;
import java.io.*;
import java.util.Enumeration;
import java.util.logging.Level;
import java.lang.ref.SoftReference;
import javax.mail.*;
import javax.mail.internet.*;
import javax.mail.event.*;
import com.sun.mail.util.ReadableMime;
/**
* A POP3 Message. Just like a MimeMessage except that
* some things are not supported.
*
* @author Bill Shannon
*/
public class POP3Message extends MimeMessage implements ReadableMime {
/*
* Our locking strategy is to always lock the POP3Folder before the
* POP3Message so we have to be careful to drop our lock before calling
* back to the folder to close it and notify of connection lost events.
*/
// flag to indicate we haven't tried to fetch the UID yet
static final String UNKNOWN = "UNKNOWN";
private POP3Folder folder; // overrides folder in MimeMessage
private int hdrSize = -1;
private int msgSize = -1;
String uid = UNKNOWN; // controlled by folder lock
// rawData itself is never null
private SoftReference rawData
= new SoftReference<>(null);
public POP3Message(Folder folder, int msgno)
throws MessagingException {
super(folder, msgno);
assert folder instanceof POP3Folder;
this.folder = (POP3Folder)folder;
}
/**
* Set the specified flags on this message to the specified value.
*
* @param newFlags the flags to be set
* @param set the value to be set
*/
@Override
public synchronized void setFlags(Flags newFlags, boolean set)
throws MessagingException {
Flags oldFlags = (Flags)flags.clone();
super.setFlags(newFlags, set);
if (!flags.equals(oldFlags))
folder.notifyMessageChangedListeners(
MessageChangedEvent.FLAGS_CHANGED, this);
}
/**
* Return the size of the content of this message in bytes.
* Returns -1 if the size cannot be determined.
*
* Note that this number may not be an exact measure of the
* content size and may or may not account for any transfer
* encoding of the content.
*
* @return size of content in bytes
* @exception MessagingException for failures
*/
@Override
public int getSize() throws MessagingException {
try {
synchronized (this) {
// if we already have the size, return it
if (msgSize > 0)
return msgSize;
}
/*
* Use LIST to determine the entire message
* size and subtract out the header size
* (which may involve loading the headers,
* which may load the content as a side effect).
* If the content is loaded as a side effect of
* loading the headers, it will set the size.
*
* Make sure to call loadHeaders() outside of the
* synchronization block. There's a potential race
* condition here but synchronization will occur in
* loadHeaders() to make sure the headers are only
* loaded once, and again in the following block to
* only compute msgSize once.
*/
if (headers == null)
loadHeaders();
synchronized (this) {
if (msgSize < 0)
msgSize = folder.getProtocol().list(msgnum) - hdrSize;
return msgSize;
}
} catch (EOFException eex) {
folder.close(false);
throw new FolderClosedException(folder, eex.toString());
} catch (IOException ex) {
throw new MessagingException("error getting size", ex);
}
}
/**
* Produce the raw bytes of the message. The data is fetched using
* the POP3 RETR command. If skipHeader is true, just the content
* is returned.
*/
private InputStream getRawStream(boolean skipHeader)
throws MessagingException {
InputStream rawcontent = null;
try {
synchronized(this) {
rawcontent = rawData.get();
if (rawcontent == null) {
TempFile cache = folder.getFileCache();
if (cache != null) {
if (folder.logger.isLoggable(Level.FINE))
folder.logger.fine("caching message #" + msgnum +
" in temp file");
AppendStream os = cache.getAppendStream();
BufferedOutputStream bos = new BufferedOutputStream(os);
try {
folder.getProtocol().retr(msgnum, bos);
} finally {
bos.close();
}
rawcontent = os.getInputStream();
} else {
rawcontent = folder.getProtocol().retr(msgnum,
msgSize > 0 ? msgSize + hdrSize : 0);
}
if (rawcontent == null) {
expunged = true;
throw new MessageRemovedException(
"can't retrieve message #" + msgnum +
" in POP3Message.getContentStream"); // XXX - what else?
}
if (headers == null ||
((POP3Store)(folder.getStore())).forgetTopHeaders) {
headers = new InternetHeaders(rawcontent);
hdrSize =
(int)((SharedInputStream)rawcontent).getPosition();
} else {
/*
* Already have the headers, have to skip the headers
* in the content array and return the body.
*
* XXX - It seems that some mail servers return slightly
* different headers in the RETR results than were returned
* in the TOP results, so we can't depend on remembering
* the size of the headers from the TOP command and just
* skipping that many bytes. Instead, we have to process
* the content, skipping over the header until we come to
* the empty line that separates the header from the body.
*/
int offset = 0;
for (;;) {
int len = 0; // number of bytes in this line
int c1;
while ((c1 = rawcontent.read()) >= 0) {
if (c1 == '\n') // end of line
break;
else if (c1 == '\r') {
// got CR, is the next char LF?
if (rawcontent.available() > 0) {
rawcontent.mark(1);
if (rawcontent.read() != '\n')
rawcontent.reset();
}
break; // in any case, end of line
}
// not CR, NL, or CRLF, count the byte
len++;
}
// here when end of line or out of data
// if out of data, we're done
if (rawcontent.available() == 0)
break;
// if it was an empty line, we're done
if (len == 0)
break;
}
hdrSize =
(int)((SharedInputStream)rawcontent).getPosition();
}
// skipped the header, the message is what's left
msgSize = rawcontent.available();
rawData = new SoftReference<>(rawcontent);
}
}
} catch (EOFException eex) {
folder.close(false);
throw new FolderClosedException(folder, eex.toString());
} catch (IOException ex) {
throw new MessagingException("error fetching POP3 content", ex);
}
/*
* We have a cached stream, but we need to return
* a fresh stream to read from the beginning and
* that can be safely closed.
*/
rawcontent = ((SharedInputStream)rawcontent).newStream(
skipHeader ? hdrSize : 0, -1);
return rawcontent;
}
/**
* Produce the raw bytes of the content. The data is fetched using
* the POP3 RETR command.
*
* @see #contentStream
*/
@Override
protected synchronized InputStream getContentStream()
throws MessagingException {
if (contentStream != null)
return ((SharedInputStream)contentStream).newStream(0, -1);
InputStream cstream = getRawStream(true);
/*
* Keep a hard reference to the data if we're using a file
* cache or if the "mail.pop3.keepmessagecontent" prop is set.
*/
TempFile cache = folder.getFileCache();
if (cache != null ||
((POP3Store)(folder.getStore())).keepMessageContent)
contentStream = ((SharedInputStream)cstream).newStream(0, -1);
return cstream;
}
/**
* Return the MIME format stream corresponding to this message part.
*
* @return the MIME format stream
* @since JavaMail 1.4.5
*/
@Override
public InputStream getMimeStream() throws MessagingException {
return getRawStream(false);
}
/**
* Invalidate the cache of content for this message object, causing
* it to be fetched again from the server the next time it is needed.
* If invalidateHeaders is true, invalidate the headers
* as well.
*
* @param invalidateHeaders invalidate the headers as well?
*/
public synchronized void invalidate(boolean invalidateHeaders) {
content = null;
InputStream rstream = rawData.get();
if (rstream != null) {
// note that if the content is in the file cache, it will be lost
// and fetched from the server if it's needed again
try {
rstream.close();
} catch (IOException ex) {
// ignore it
}
rawData = new SoftReference<>(null);
}
if (contentStream != null) {
try {
contentStream.close();
} catch (IOException ex) {
// ignore it
}
contentStream = null;
}
msgSize = -1;
if (invalidateHeaders) {
headers = null;
hdrSize = -1;
}
}
/**
* Fetch the header of the message and the first n lines
* of the raw content of the message. The headers and data are
* available in the returned InputStream.
*
* @param n number of lines of content to fetch
* @return InputStream containing the message headers and n content lines
* @exception MessagingException for failures
*/
public InputStream top(int n) throws MessagingException {
try {
synchronized (this) {
return folder.getProtocol().top(msgnum, n);
}
} catch (EOFException eex) {
folder.close(false);
throw new FolderClosedException(folder, eex.toString());
} catch (IOException ex) {
throw new MessagingException("error getting size", ex);
}
}
/**
* Get all the headers for this header_name. Note that certain
* headers may be encoded as per RFC 2047 if they contain
* non US-ASCII characters and these should be decoded.
*
* @param name name of header
* @return array of headers
* @exception MessagingException for failures
* @see javax.mail.internet.MimeUtility
*/
@Override
public String[] getHeader(String name)
throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getHeader(name);
}
/**
* Get all the headers for this header name, returned as a single
* String, with headers separated by the delimiter. If the
* delimiter is null, only the first header is
* returned.
*
* @param name the name of this header
* @param delimiter delimiter between returned headers
* @return the value fields for all headers with
* this name
* @exception MessagingException for failures
*/
@Override
public String getHeader(String name, String delimiter)
throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getHeader(name, delimiter);
}
/**
* Set the value for this header_name. Throws IllegalWriteException
* because POP3 messages are read-only.
*
* @param name header name
* @param value header value
* @see javax.mail.internet.MimeUtility
* @exception IllegalWriteException because the underlying
* implementation does not support modification
* @exception IllegalStateException if this message is
* obtained from a READ_ONLY folder.
* @exception MessagingException for other failures
*/
@Override
public void setHeader(String name, String value)
throws MessagingException {
// XXX - should check for read-only folder?
throw new IllegalWriteException("POP3 messages are read-only");
}
/**
* Add this value to the existing values for this header_name.
* Throws IllegalWriteException because POP3 messages are read-only.
*
* @param name header name
* @param value header value
* @see javax.mail.internet.MimeUtility
* @exception IllegalWriteException because the underlying
* implementation does not support modification
* @exception IllegalStateException if this message is
* obtained from a READ_ONLY folder.
*/
@Override
public void addHeader(String name, String value)
throws MessagingException {
// XXX - should check for read-only folder?
throw new IllegalWriteException("POP3 messages are read-only");
}
/**
* Remove all headers with this name.
* Throws IllegalWriteException because POP3 messages are read-only.
*
* @exception IllegalWriteException because the underlying
* implementation does not support modification
* @exception IllegalStateException if this message is
* obtained from a READ_ONLY folder.
*/
@Override
public void removeHeader(String name)
throws MessagingException {
// XXX - should check for read-only folder?
throw new IllegalWriteException("POP3 messages are read-only");
}
/**
* Return all the headers from this Message as an enumeration
* of Header objects.
*
* Note that certain headers may be encoded as per RFC 2047
* if they contain non US-ASCII characters and these should
* be decoded.
*
* @return array of header objects
* @exception MessagingException for failures
* @see javax.mail.internet.MimeUtility
*/
@Override
public Enumeration getAllHeaders() throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getAllHeaders();
}
/**
* Return matching headers from this Message as an Enumeration of
* Header objects.
*
* @exception MessagingException for failures
*/
@Override
public Enumeration getMatchingHeaders(String[] names)
throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getMatchingHeaders(names);
}
/**
* Return non-matching headers from this Message as an
* Enumeration of Header objects.
*
* @exception MessagingException for failures
*/
@Override
public Enumeration getNonMatchingHeaders(String[] names)
throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getNonMatchingHeaders(names);
}
/**
* Add a raw RFC822 header-line.
* Throws IllegalWriteException because POP3 messages are read-only.
*
* @exception IllegalWriteException because the underlying
* implementation does not support modification
* @exception IllegalStateException if this message is
* obtained from a READ_ONLY folder.
*/
@Override
public void addHeaderLine(String line) throws MessagingException {
// XXX - should check for read-only folder?
throw new IllegalWriteException("POP3 messages are read-only");
}
/**
* Get all header lines as an Enumeration of Strings. A Header
* line is a raw RFC822 header-line, containing both the "name"
* and "value" field.
*
* @exception MessagingException for failures
*/
@Override
public Enumeration getAllHeaderLines() throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getAllHeaderLines();
}
/**
* Get matching header lines as an Enumeration of Strings.
* A Header line is a raw RFC822 header-line, containing both
* the "name" and "value" field.
*
* @exception MessagingException for failures
*/
@Override
public Enumeration getMatchingHeaderLines(String[] names)
throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getMatchingHeaderLines(names);
}
/**
* Get non-matching header lines as an Enumeration of Strings.
* A Header line is a raw RFC822 header-line, containing both
* the "name" and "value" field.
*
* @exception MessagingException for failures
*/
@Override
public Enumeration getNonMatchingHeaderLines(String[] names)
throws MessagingException {
if (headers == null)
loadHeaders();
return headers.getNonMatchingHeaderLines(names);
}
/**
* POP3 message can't be changed. This method throws
* IllegalWriteException.
*
* @exception IllegalWriteException because the underlying
* implementation does not support modification
*/
@Override
public void saveChanges() throws MessagingException {
// POP3 Messages are read-only
throw new IllegalWriteException("POP3 messages are read-only");
}
/**
* Output the message as an RFC 822 format stream, without
* specified headers. If the property "mail.pop3.cachewriteto"
* is set to "true", and ignoreList is null, and the message hasn't
* already been cached as a side effect of other operations, the message
* content is cached before being written. Otherwise, the message is
* streamed directly to the output stream without being cached.
*
* @exception IOException if an error occurs writing to the stream
* or if an error is generated by the
* javax.activation layer.
* @exception MessagingException for other failures
* @see javax.activation.DataHandler#writeTo
*/
@Override
public synchronized void writeTo(OutputStream os, String[] ignoreList)
throws IOException, MessagingException {
InputStream rawcontent = rawData.get();
if (rawcontent == null && ignoreList == null &&
!((POP3Store)(folder.getStore())).cacheWriteTo) {
if (folder.logger.isLoggable(Level.FINE))
folder.logger.fine("streaming msg " + msgnum);
if (!folder.getProtocol().retr(msgnum, os)) {
expunged = true;
throw new MessageRemovedException("can't retrieve message #" +
msgnum + " in POP3Message.writeTo"); // XXX - what else?
}
} else if (rawcontent != null && ignoreList == null) {
// can just copy the cached data
InputStream in = ((SharedInputStream)rawcontent).newStream(0, -1);
try {
byte[] buf = new byte[16*1024];
int len;
while ((len = in.read(buf)) > 0)
os.write(buf, 0, len);
} finally {
try {
if (in != null)
in.close();
} catch (IOException ex) { }
}
} else
super.writeTo(os, ignoreList);
}
/**
* Load the headers for this message into the InternetHeaders object.
* The headers are fetched using the POP3 TOP command.
*/
private void loadHeaders() throws MessagingException {
assert !Thread.holdsLock(this);
try {
boolean fetchContent = false;
synchronized (this) {
if (headers != null) // check again under lock
return;
InputStream hdrs = null;
if (((POP3Store)(folder.getStore())).disableTop ||
(hdrs = folder.getProtocol().top(msgnum, 0)) == null) {
// possibly because the TOP command isn't supported,
// load headers as a side effect of loading the entire
// content.
fetchContent = true;
} else {
try {
hdrSize = hdrs.available();
headers = new InternetHeaders(hdrs);
} finally {
hdrs.close();
}
}
}
/*
* Outside the synchronization block...
*
* Do we need to fetch the entire mesage content in order to
* load the headers as a side effect? Yes, there's a race
* condition here - multiple threads could decide that the
* content needs to be fetched. Fortunately, they'll all
* synchronize in the getContentStream method and the content
* will only be loaded once.
*/
if (fetchContent) {
InputStream cs = null;
try {
cs = getContentStream();
} finally {
if (cs != null)
cs.close();
}
}
} catch (EOFException eex) {
folder.close(false);
throw new FolderClosedException(folder, eex.toString());
} catch (IOException ex) {
throw new MessagingException("error loading POP3 headers", ex);
}
}
}