com.sun.mail.pop3.TempFile Maven / Gradle / Ivy
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2010-2011 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.mail.pop3;
import java.util.*;
import java.net.*;
import java.io.*;
import java.security.*;
import com.sun.mail.util.PropUtil;
import javax.mail.util.SharedFileInputStream;
/**
* A temporary file used to cache POP3 messages.
*/
class TempFile {
private File file; // the temp file name
private WritableSharedFile sf;
/**
* Create a temp file in the specified directory (if not null).
* The file will be deleted when the JVM exits.
*/
public TempFile(File dir) throws IOException {
file = File.createTempFile("pop3.", ".mbox", dir);
// XXX - need JDK 6 to set permissions on the file to owner-only
file.deleteOnExit();
sf = new WritableSharedFile(file);
}
/**
* Return a stream for appending to the temp file.
*/
public AppendStream getAppendStream() throws IOException {
return sf.getAppendStream();
}
/**
* Close and remove this temp file.
*/
public void close() {
try {
sf.close();
} catch (IOException ex) {
// ignore it
}
file.delete();
}
protected void finalize() throws Throwable {
super.finalize();
close();
}
}
/**
* A subclass of SharedFileInputStream that also allows writing.
*/
class WritableSharedFile extends SharedFileInputStream {
private RandomAccessFile raf;
private AppendStream af;
public WritableSharedFile(File file) throws IOException {
super(file);
try {
raf = new RandomAccessFile(file, "rw");
} catch (IOException ex) {
// if anything goes wrong opening the writable file,
// close the readable file too
super.close();
}
}
/**
* Return the writable version of this file.
*/
public RandomAccessFile getWritableFile() {
return raf;
}
/**
* Close the readable and writable files.
*/
public void close() throws IOException {
try {
super.close();
} finally {
raf.close();
}
}
/**
* Update the size of the readable file after writing
* to the file. Updates the length to be the current
* size of the file.
*/
synchronized long updateLength() throws IOException {
datalen = in.length();
af = null;
return datalen;
}
/**
* Return a new AppendStream, but only if one isn't in active use.
*/
public synchronized AppendStream getAppendStream() throws IOException {
if (af != null)
throw new IOException(
"POP3 file cache only supports single threaded access");
af = new AppendStream(this);
return af;
}
}
/**
* A stream for writing to the temp file, and when done
* can return a stream for reading the data just written.
* NOTE: We assume that only one thread is writing to the
* file at a time.
*/
class AppendStream extends OutputStream {
private final WritableSharedFile tf;
private RandomAccessFile raf;
private final long start;
private long end;
public AppendStream(WritableSharedFile tf) throws IOException {
this.tf = tf;
raf = tf.getWritableFile();
start = raf.length();
raf.seek(start);
}
public void write(int b) throws IOException {
raf.write(b);
}
public void write(byte[] b) throws IOException {
raf.write(b);
}
public void write(byte[] b, int off, int len) throws IOException {
raf.write(b, off, len);
}
public synchronized void close() throws IOException {
end = tf.updateLength();
raf = null; // no more writing allowed
}
public synchronized InputStream getInputStream() throws IOException {
return tf.newStream(start, end);
}
}