/*
* Copyright 2004-2010 the Seasar Foundation and the Others.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package org.slim3.controller.upload;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
/**
* Low level API for processing file uploads.
*
* @author <a href="mailto:Rafal.Krzewski@e-point.pl">Rafal Krzewski</a>
* @author <a href="mailto:martinc@apache.org">Martin Cooper</a>
* @author Sean C. Sullivan
* @author higa
* @since 1.0.0
*
*/
public class MultipartStream {
/**
* The Carriage Return ASCII character value.
*/
public static final byte CR = 0x0D;
/**
* The Line Feed ASCII character value.
*/
public static final byte LF = 0x0A;
/**
* The dash (-) ASCII character value.
*/
public static final byte DASH = 0x2D;
/**
* The maximum length of <code>header-part</code> that will be processed (10
* kilobytes = 10240 bytes.).
*/
public static final int HEADER_PART_SIZE_MAX = 10240;
/**
* The default length of the buffer used for processing a request.
*/
protected static final int DEFAULT_BUFSIZE = 4096;
/**
* A byte sequence that marks the end of <code>header-part</code> (
* <code>CRLFCRLF</code>).
*/
protected static final byte[] HEADER_SEPARATOR = { CR, LF, CR, LF };
/**
* A byte sequence that that follows a delimiter that will be followed by an
* encapsulation (<code>CRLF</code>).
*/
protected static final byte[] FIELD_SEPARATOR = { CR, LF };
/**
* A byte sequence that that follows a delimiter of the last encapsulation
* in the stream (<code>--</code>).
*/
protected static final byte[] STREAM_TERMINATOR = { DASH, DASH };
/**
* A byte sequence that precedes a boundary (<code>CRLF--</code>).
*/
protected static final byte[] BOUNDARY_PREFIX = { CR, LF, DASH, DASH };
/**
* The input stream from which data is read.
*/
protected InputStream input;
/**
* The length of the boundary token plus the leading <code>CRLF--</code>.
*/
protected int boundaryLength;
/**
* The amount of data, in bytes, that must be kept in the buffer in order to
* detect delimiters reliably.
*/
protected int keepRegion;
/**
* The byte sequence that partitions the stream.
*/
protected byte[] boundary;
/**
* The length of the buffer used for processing the request.
*/
protected int bufSize;
/**
* The buffer used for processing the request.
*/
protected byte[] buffer;
/**
* The index of first valid character in the buffer. <br>
* 0 <= head < bufSize
*/
protected int head;
/**
* The index of last valid characer in the buffer + 1. <br>
* 0 <= tail <= bufSize
*/
protected int tail;
/**
* The content encoding to use when reading headers.
*/
protected String headerEncoding;
/**
* Constructor.
*
* @param input
* The <code>InputStream</code> to serve as a data source
* @param boundary
* The token used for dividing the stream into
* <code>encapsulations</code>
*/
public MultipartStream(InputStream input, byte[] boundary) {
this(input, boundary, DEFAULT_BUFSIZE);
}
/**
* Constructor.
*
* @param input
* The <code>InputStream</code> to serve as a data source.
* @param boundary
* The token used for dividing the stream into
* <code>encapsulations</code>.
* @param bufSize
* The size of the buffer to be used, in bytes.
*/
public MultipartStream(InputStream input, byte[] boundary, int bufSize) {
this.input = input;
this.bufSize = bufSize;
this.buffer = new byte[bufSize];
// We prepend CR/LF to the boundary to chop trailng CR/LF from
// body-data tokens.
this.boundary = new byte[boundary.length + BOUNDARY_PREFIX.length];
this.boundaryLength = boundary.length + BOUNDARY_PREFIX.length;
this.keepRegion = this.boundary.length;
System.arraycopy(
BOUNDARY_PREFIX,
0,
this.boundary,
0,
BOUNDARY_PREFIX.length);
System.arraycopy(
boundary,
0,
this.boundary,
BOUNDARY_PREFIX.length,
boundary.length);
head = 0;
tail = 0;
}
/**
* Retrieves the character encoding used when reading the headers of an
* individual part. When not specified, or <code>null</code>, the platform
* default encoding is used.
*
*
* @return The encoding used to read part headers.
*/
public String getHeaderEncoding() {
return headerEncoding;
}
/**
* Specifies the character encoding to be used when reading the headers of
* individual parts. When not specified, or <code>null</code>, the platform
* default encoding is used.
*
* @param encoding
* The encoding used to read part headers.
*/
public void setHeaderEncoding(String encoding) {
headerEncoding = encoding;
}
/**
* Reads a byte from the <code>buffer</code>, and refills it as necessary.
*
* @return The next byte from the input stream
*
* @throws IOException
* if there is no more data available.
*/
public byte readByte() throws IOException {
// Buffer depleted ?
if (head == tail) {
head = 0;
// Refill.
tail = input.read(buffer, head, bufSize);
if (tail == -1) {
// No more data available.
throw new IOException("No more data is available");
}
}
return buffer[head++];
}
/**
* Skips a <code>boundary</code> token, and checks whether more
* <code>encapsulations</code> are contained in the stream.
*
* @return <code>true</code> if there are more encapsulations in this
* stream; <code>false</code> otherwise.
*
* @throws MalformedStreamException
* if the stream ends unexpecetedly or fails to follow required
* syntax.
*/
public boolean readBoundary() throws MalformedStreamException {
byte[] marker = new byte[2];
boolean nextChunk = false;
head += boundaryLength;
try {
marker[0] = readByte();
if (marker[0] == LF) {
// Work around IE5 Mac bug with input type=image.
// Because the boundary delimiter, not including the trailing
// CRLF, must not appear within any file (RFC 2046, section
// 5.1.1), we know the missing CR is due to a buggy browser
// rather than a file containing something similar to a
// boundary.
return true;
}
marker[1] = readByte();
if (arrayequals(marker, STREAM_TERMINATOR, 2)) {
nextChunk = false;
} else if (arrayequals(marker, FIELD_SEPARATOR, 2)) {
nextChunk = true;
} else {
throw new MalformedStreamException(
"Unexpected characters follow a boundary");
}
} catch (IOException e) {
throw new MalformedStreamException("Stream ended unexpectedly");
}
return nextChunk;
}
/**
* <p>
* Changes the boundary token used for partitioning the stream.
*
* <p>
* This method allows single pass processing of nested multipart streams.
*
* <p>
* The boundary token of the nested stream is <code>required</code> to be of
* the same length as the boundary token in parent stream.
*
* <p>
* Restoring the parent stream boundary token after processing of a nested
* stream is left to the application.
*
* @param boundary
* The boundary to be used for parsing of the nested stream.
*
* @throws IllegalBoundaryException
* if the <code>boundary</code> has a different length than the
* one being currently parsed.
*/
public void setBoundary(byte[] boundary) throws IllegalBoundaryException {
if (boundary.length != boundaryLength - BOUNDARY_PREFIX.length) {
throw new IllegalBoundaryException(
"The length of a boundary token can not be changed");
}
System.arraycopy(
boundary,
0,
this.boundary,
BOUNDARY_PREFIX.length,
boundary.length);
}
/**
* <p>
* Reads the <code>header-part</code> of the current
* <code>encapsulation</code>.
*
* <p>
* Headers are returned verbatim to the input stream, including the trailing
* <code>CRLF</code> marker. Parsing is left to the application.
*
*
* @return The <code>header-part</code> of the current encapsulation.
*
* @throws MalformedStreamException
* if the stream ends unexpecetedly.
*/
public String readHeaders() throws MalformedStreamException {
int i = 0;
byte b;
// to support multi-byte characters
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int size = 0;
while (i < HEADER_SEPARATOR.length) {
try {
b = readByte();
} catch (IOException e) {
throw new MalformedStreamException("Stream ended unexpectedly");
}
if (++size > HEADER_PART_SIZE_MAX) {
throw new MalformedStreamException(
"Header section has more than "
+ HEADER_PART_SIZE_MAX
+ " bytes (maybe it is not properly terminated)");
}
if (b == HEADER_SEPARATOR[i]) {
i++;
} else {
i = 0;
}
baos.write(b);
}
String headers = null;
if (headerEncoding != null) {
try {
headers = baos.toString(headerEncoding);
} catch (UnsupportedEncodingException e) {
// Fall back to platform default if specified encoding is not
// supported.
headers = baos.toString();
}
} else {
headers = baos.toString();
}
return headers;
}
/**
* <p>
* Reads <code>body-data</code> from the current <code>encapsulation</code>
* and writes its contents into the output <code>Stream</code>.
*
* <p>
* Arbitrary large amounts of data can be processed by this method using a
* constant size buffer.
*
* @param output
* The <code>Stream</code> to write data into. May be null, in
* which case this method is equivalent to
* {@link #discardBodyData()}.
*
* @return the amount of data written.
*
* @throws MalformedStreamException
* if the stream ends unexpectedly.
* @throws IOException
* if an i/o error occurs.
*/
public int readBodyData(OutputStream output)
throws MalformedStreamException, IOException {
final InputStream istream = newInputStream();
return (int) Streams.copy(istream, output, false);
}
/**
* Creates a new {@link ItemInputStream}.
*
* @return A new instance of {@link ItemInputStream}.
*/
ItemInputStream newInputStream() {
return new ItemInputStream();
}
/**
* <p>
* Reads <code>body-data</code> from the current <code>encapsulation</code>
* and discards it.
*
* <p>
* Use this method to skip encapsulations you don't need or don't
* understand.
*
* @return The amount of data discarded.
*
* @throws MalformedStreamException
* if the stream ends unexpectedly.
* @throws IOException
* if an i/o error occurs.
*/
public int discardBodyData() throws MalformedStreamException, IOException {
return readBodyData(null);
}
/**
* Finds the beginning of the first <code>encapsulation</code>.
*
* @return <code>true</code> if an <code>encapsulation</code> was found in
* the stream.
*
* @throws IOException
* if an i/o error occurs.
*/
public boolean skipPreamble() throws IOException {
// First delimiter may be not preceeded with a CRLF.
System.arraycopy(boundary, 2, boundary, 0, boundary.length - 2);
boundaryLength = boundary.length - 2;
try {
// Discard all data up to the delimiter.
discardBodyData();
// Read boundary - if succeded, the stream contains an
// encapsulation.
return readBoundary();
} catch (MalformedStreamException e) {
return false;
} finally {
// Restore delimiter.
System.arraycopy(boundary, 0, boundary, 2, boundary.length - 2);
boundaryLength = boundary.length;
boundary[0] = CR;
boundary[1] = LF;
}
}
/**
* Compares <code>count</code> first bytes in the arrays <code>a</code> and
* <code>b</code>.
*
* @param a
* The first array to compare.
* @param b
* The second array to compare.
* @param count
* How many bytes should be compared.
*
* @return <code>true</code> if <code>count</code> first bytes in arrays
* <code>a</code> and <code>b</code> are equal.
*/
public static boolean arrayequals(byte[] a, byte[] b, int count) {
for (int i = 0; i < count; i++) {
if (a[i] != b[i]) {
return false;
}
}
return true;
}
/**
* Searches for a byte of specified value in the <code>buffer</code>,
* starting at the specified <code>position</code>.
*
* @param value
* The value to find.
* @param pos
* The starting position for searching.
*
* @return The position of byte found, counting from beginning of the
* <code>buffer</code>, or <code>-1</code> if not found.
*/
protected int findByte(byte value, int pos) {
for (int i = pos; i < tail; i++) {
if (buffer[i] == value) {
return i;
}
}
return -1;
}
/**
* Searches for the <code>boundary</code> in the <code>buffer</code> region
* delimited by <code>head</code> and <code>tail</code>.
*
* @return The position of the boundary found, counting from the beginning
* of the <code>buffer</code>, or <code>-1</code> if not found.
*/
protected int findSeparator() {
int first;
int match = 0;
int maxpos = tail - boundaryLength;
for (first = head; (first <= maxpos) && (match != boundaryLength); first++) {
first = findByte(boundary[0], first);
if (first == -1 || (first > maxpos)) {
return -1;
}
for (match = 1; match < boundaryLength; match++) {
if (buffer[first + match] != boundary[match]) {
break;
}
}
}
if (match == boundaryLength) {
return first - 1;
}
return -1;
}
/**
* Thrown to indicate that the input stream fails to follow the required
* syntax.
*/
public static class MalformedStreamException extends IOException {
private static final long serialVersionUID = 1L;
/**
* Constructs a <code>MalformedStreamException</code> with no detail
* message.
*/
public MalformedStreamException() {
super();
}
/**
* Constructs an <code>MalformedStreamException</code> with the
* specified detail message.
*
* @param message
* The detail message.
*/
public MalformedStreamException(String message) {
super(message);
}
}
/**
* Thrown upon attempt of setting an invalid boundary token.
*/
public static class IllegalBoundaryException extends IOException {
private static final long serialVersionUID = 1L;
/**
* Constructs an <code>IllegalBoundaryException</code> with no detail
* message.
*/
public IllegalBoundaryException() {
super();
}
/**
* Constructs an <code>IllegalBoundaryException</code> with the
* specified detail message.
*
* @param message
* The detail message.
*/
public IllegalBoundaryException(String message) {
super(message);
}
}
/**
* An {@link InputStream} for reading an items contents.
*/
public class ItemInputStream extends InputStream {
/**
* The number of bytes, which have been read so far.
*/
protected long total;
/**
* The number of bytes, which must be hold, because they might be a part
* of the boundary.
*/
protected int pad;
/**
* The current offset in the buffer.
*/
protected int pos;
/**
* Whether the stream is already closed.
*/
protected boolean closed;
/**
* Constructor.
*/
ItemInputStream() {
findSeparator();
}
/**
* Called for finding the separator.
*/
protected void findSeparator() {
pos = MultipartStream.this.findSeparator();
if (pos == -1) {
if (tail - head > keepRegion) {
pad = keepRegion;
} else {
pad = tail - head;
}
}
}
/**
* Returns the number of bytes, which have been read by the stream.
*
* @return Number of bytes, which have been read so far.
*/
public long getBytesRead() {
return total;
}
/**
* Returns the number of bytes, which are currently available, without
* blocking.
*
* @throws IOException
* An I/O error occurs.
* @return Number of bytes in the buffer.
*/
@Override
public int available() throws IOException {
if (pos == -1) {
return tail - head - pad;
}
return pos - head;
}
/**
* Offset when converting negative bytes to integers.
*/
protected static final int BYTE_POSITIVE_OFFSET = 256;
/**
* Returns the next byte in the stream.
*
* @return The next byte in the stream, as a non-negative integer, or -1
* for EOF.
* @throws IOException
* An I/O error occurred.
*/
@Override
public int read() throws IOException {
if (closed) {
throw new IllegalStateException(
"This stream has bean already closed.");
}
if (available() == 0) {
if (makeAvailable() == 0) {
return -1;
}
}
++total;
int b = buffer[head++];
if (b >= 0) {
return b;
}
return b + BYTE_POSITIVE_OFFSET;
}
/**
* Reads bytes into the given buffer.
*
* @param b
* The destination buffer, where to write to.
* @param off
* Offset of the first byte in the buffer.
* @param len
* Maximum number of bytes to read.
* @return Number of bytes, which have been actually read, or -1 for
* EOF.
* @throws IOException
* An I/O error occurred.
*/
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (closed) {
throw new IllegalStateException(
"This stream has bean already closed.");
}
if (len == 0) {
return 0;
}
int res = available();
if (res == 0) {
res = makeAvailable();
if (res == 0) {
return -1;
}
}
res = Math.min(res, len);
System.arraycopy(buffer, head, b, off, res);
head += res;
total += res;
return res;
}
/**
* Closes the input stream.
*
* @throws IOException
* An I/O error occurred.
*/
@Override
public void close() throws IOException {
close(false);
}
/**
* Closes the input stream.
*
* @param closeUnderlying
* Whether to close the underlying stream (hard close)
* @throws IOException
* An I/O error occurred.
*/
public void close(boolean closeUnderlying) throws IOException {
if (closed) {
return;
}
if (closeUnderlying) {
closed = true;
input.close();
} else {
for (;;) {
int av = available();
if (av == 0) {
av = makeAvailable();
if (av == 0) {
break;
}
}
skip(av);
}
}
closed = true;
}
/**
* Skips the given number of bytes.
*
* @param bytes
* Number of bytes to skip.
* @return The number of bytes, which have actually been skipped.
* @throws IOException
* An I/O error occurred.
*/
@Override
public long skip(long bytes) throws IOException {
if (closed) {
throw new IllegalStateException(
"This stream has bean already closed.");
}
int av = available();
if (av == 0) {
av = makeAvailable();
if (av == 0) {
return 0;
}
}
long res = Math.min(av, bytes);
head += res;
return res;
}
/**
* Attempts to read more data.
*
* @return Number of available bytes
* @throws IOException
* An I/O error occurred.
*/
protected int makeAvailable() throws IOException {
if (pos != -1) {
return 0;
}
// Move the data to the beginning of the buffer.
total += tail - head - pad;
System.arraycopy(buffer, tail - pad, buffer, 0, pad);
// Refill buffer with new data.
head = 0;
tail = pad;
for (;;) {
int bytesRead = input.read(buffer, tail, bufSize - tail);
if (bytesRead == -1) {
// The last pad amount is left in the buffer.
// Boundary can't be in there so signal an error
// condition.
final String msg = "Stream ended unexpectedly";
throw new MalformedStreamException(msg);
}
tail += bytesRead;
findSeparator();
int av = available();
if (av > 0 || pos != -1) {
return av;
}
}
}
/**
* Returns, whether the stream is closed.
*
* @return True, if the stream is closed, otherwise false.
*/
public boolean isClosed() {
return closed;
}
}
}