Source Code Cross Referenced for MultipartStream.java in  » Net » apache-common-FileUpload » org » apache » commons » fileupload » Java Source Code / Java DocumentationJava Source Code and Java Documentation

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Java Source Code / Java Documentation » Net » apache common FileUpload » org.apache.commons.fileupload 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


0001:        /*
0002:         * Licensed to the Apache Software Foundation (ASF) under one or more
0003:         * contributor license agreements.  See the NOTICE file distributed with
0004:         * this work for additional information regarding copyright ownership.
0005:         * The ASF licenses this file to You under the Apache License, Version 2.0
0006:         * (the "License"); you may not use this file except in compliance with
0007:         * the License.  You may obtain a copy of the License at
0008:         *
0009:         *      http://www.apache.org/licenses/LICENSE-2.0
0010:         *
0011:         * Unless required by applicable law or agreed to in writing, software
0012:         * distributed under the License is distributed on an "AS IS" BASIS,
0013:         * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
0014:         * See the License for the specific language governing permissions and
0015:         * limitations under the License.
0016:         */
0017:        package org.apache.commons.fileupload;
0018:
0019:        import java.io.ByteArrayOutputStream;
0020:        import java.io.IOException;
0021:        import java.io.InputStream;
0022:        import java.io.OutputStream;
0023:        import java.io.UnsupportedEncodingException;
0024:
0025:        import org.apache.commons.fileupload.util.Closeable;
0026:        import org.apache.commons.fileupload.util.Streams;
0027:
0028:        /**
0029:         * <p> Low level API for processing file uploads.
0030:         *
0031:         * <p> This class can be used to process data streams conforming to MIME
0032:         * 'multipart' format as defined in
0033:         * <a href="http://www.ietf.org/rfc/rfc1867.txt">RFC 1867</a>. Arbitrarily
0034:         * large amounts of data in the stream can be processed under constant
0035:         * memory usage.
0036:         *
0037:         * <p> The format of the stream is defined in the following way:<br>
0038:         *
0039:         * <code>
0040:         *   multipart-body := preamble 1*encapsulation close-delimiter epilogue<br>
0041:         *   encapsulation := delimiter body CRLF<br>
0042:         *   delimiter := "--" boundary CRLF<br>
0043:         *   close-delimiter := "--" boudary "--"<br>
0044:         *   preamble := &lt;ignore&gt;<br>
0045:         *   epilogue := &lt;ignore&gt;<br>
0046:         *   body := header-part CRLF body-part<br>
0047:         *   header-part := 1*header CRLF<br>
0048:         *   header := header-name ":" header-value<br>
0049:         *   header-name := &lt;printable ascii characters except ":"&gt;<br>
0050:         *   header-value := &lt;any ascii characters except CR & LF&gt;<br>
0051:         *   body-data := &lt;arbitrary data&gt;<br>
0052:         * </code>
0053:         *
0054:         * <p>Note that body-data can contain another mulipart entity.  There
0055:         * is limited support for single pass processing of such nested
0056:         * streams.  The nested stream is <strong>required</strong> to have a
0057:         * boundary token of the same length as the parent stream (see {@link
0058:         * #setBoundary(byte[])}).
0059:         *
0060:         * <p>Here is an example of usage of this class.<br>
0061:         *
0062:         * <pre>
0063:         *    try {
0064:         *        MultipartStream multipartStream = new MultipartStream(input,
0065:         *                                                              boundary);
0066:         *        boolean nextPart = multipartStream.skipPreamble();
0067:         *        OutputStream output;
0068:         *        while(nextPart) {
0069:         *            header = chunks.readHeader();
0070:         *            // process headers
0071:         *            // create some output stream
0072:         *            multipartStream.readBodyPart(output);
0073:         *            nextPart = multipartStream.readBoundary();
0074:         *        }
0075:         *    } catch(MultipartStream.MalformedStreamException e) {
0076:         *          // the stream failed to follow required syntax
0077:         *    } catch(IOException) {
0078:         *          // a read or write error occurred
0079:         *    }
0080:         *
0081:         * </pre>
0082:         *
0083:         * @author <a href="mailto:Rafal.Krzewski@e-point.pl">Rafal Krzewski</a>
0084:         * @author <a href="mailto:martinc@apache.org">Martin Cooper</a>
0085:         * @author Sean C. Sullivan
0086:         *
0087:         * @version $Id: MultipartStream.java 502350 2007-02-01 20:42:48Z jochen $
0088:         */
0089:        public class MultipartStream {
0090:            /**
0091:             * Internal class, which is used to invoke the
0092:             * {@link ProgressListener}.
0093:             */
0094:            static class ProgressNotifier {
0095:                /** The listener to invoke.
0096:                 */
0097:                private final ProgressListener listener;
0098:                /** Number of expected bytes, if known, or -1.
0099:                 */
0100:                private final long contentLength;
0101:                /** Number of bytes, which have been read so far.
0102:                 */
0103:                private long bytesRead;
0104:                /** Number of items, which have been read so far.
0105:                 */
0106:                private int items;
0107:
0108:                /** Creates a new instance with the given listener
0109:                 * and content length.
0110:                 * @param pListener The listener to invoke.
0111:                 * @param pContentLength The expected content length.
0112:                 */
0113:                ProgressNotifier(ProgressListener pListener, long pContentLength) {
0114:                    listener = pListener;
0115:                    contentLength = pContentLength;
0116:                }
0117:
0118:                /** Called to indicate that bytes have been read.
0119:                 * @param pBytes Number of bytes, which have been read.
0120:                 */
0121:                void noteBytesRead(int pBytes) {
0122:                    /* Indicates, that the given number of bytes have been read from
0123:                     * the input stream.
0124:                     */
0125:                    bytesRead += pBytes;
0126:                    notifyListener();
0127:                }
0128:
0129:                /** Called to indicate, that a new file item has been detected.
0130:                 */
0131:                void noteItem() {
0132:                    ++items;
0133:                }
0134:
0135:                /** Called for notifying the listener.
0136:                 */
0137:                private void notifyListener() {
0138:                    if (listener != null) {
0139:                        listener.update(bytesRead, contentLength, items);
0140:                    }
0141:                }
0142:            }
0143:
0144:            // ----------------------------------------------------- Manifest constants
0145:
0146:            /**
0147:             * The Carriage Return ASCII character value.
0148:             */
0149:            public static final byte CR = 0x0D;
0150:
0151:            /**
0152:             * The Line Feed ASCII character value.
0153:             */
0154:            public static final byte LF = 0x0A;
0155:
0156:            /**
0157:             * The dash (-) ASCII character value.
0158:             */
0159:            public static final byte DASH = 0x2D;
0160:
0161:            /**
0162:             * The maximum length of <code>header-part</code> that will be
0163:             * processed (10 kilobytes = 10240 bytes.).
0164:             */
0165:            public static final int HEADER_PART_SIZE_MAX = 10240;
0166:
0167:            /**
0168:             * The default length of the buffer used for processing a request.
0169:             */
0170:            protected static final int DEFAULT_BUFSIZE = 4096;
0171:
0172:            /**
0173:             * A byte sequence that marks the end of <code>header-part</code>
0174:             * (<code>CRLFCRLF</code>).
0175:             */
0176:            protected static final byte[] HEADER_SEPARATOR = { CR, LF, CR, LF };
0177:
0178:            /**
0179:             * A byte sequence that that follows a delimiter that will be
0180:             * followed by an encapsulation (<code>CRLF</code>).
0181:             */
0182:            protected static final byte[] FIELD_SEPARATOR = { CR, LF };
0183:
0184:            /**
0185:             * A byte sequence that that follows a delimiter of the last
0186:             * encapsulation in the stream (<code>--</code>).
0187:             */
0188:            protected static final byte[] STREAM_TERMINATOR = { DASH, DASH };
0189:
0190:            /**
0191:             * A byte sequence that precedes a boundary (<code>CRLF--</code>).
0192:             */
0193:            protected static final byte[] BOUNDARY_PREFIX = { CR, LF, DASH,
0194:                    DASH };
0195:
0196:            /**
0197:             * The number of bytes, over and above the boundary size, to use for the
0198:             * keep region.
0199:             */
0200:            private static final int KEEP_REGION_PAD = 3;
0201:
0202:            // ----------------------------------------------------------- Data members
0203:
0204:            /**
0205:             * The input stream from which data is read.
0206:             */
0207:            private final InputStream input;
0208:
0209:            /**
0210:             * The length of the boundary token plus the leading <code>CRLF--</code>.
0211:             */
0212:            private int boundaryLength;
0213:
0214:            /**
0215:             * The amount of data, in bytes, that must be kept in the buffer in order
0216:             * to detect delimiters reliably.
0217:             */
0218:            private int keepRegion;
0219:
0220:            /**
0221:             * The byte sequence that partitions the stream.
0222:             */
0223:            private byte[] boundary;
0224:
0225:            /**
0226:             * The length of the buffer used for processing the request.
0227:             */
0228:            private final int bufSize;
0229:
0230:            /**
0231:             * The buffer used for processing the request.
0232:             */
0233:            private final byte[] buffer;
0234:
0235:            /**
0236:             * The index of first valid character in the buffer.
0237:             * <br>
0238:             * 0 <= head < bufSize
0239:             */
0240:            private int head;
0241:
0242:            /**
0243:             * The index of last valid characer in the buffer + 1.
0244:             * <br>
0245:             * 0 <= tail <= bufSize
0246:             */
0247:            private int tail;
0248:
0249:            /**
0250:             * The content encoding to use when reading headers.
0251:             */
0252:            private String headerEncoding;
0253:
0254:            /**
0255:             * The progress notifier, if any, or null.
0256:             */
0257:            private final ProgressNotifier notifier;
0258:
0259:            // ----------------------------------------------------------- Constructors
0260:
0261:            /**
0262:             * Creates a new instance.
0263:             * @deprecated Use {@link #MultipartStream(InputStream, byte[],
0264:             * org.apache.commons.fileupload.MultipartStream.ProgressNotifier)},
0265:             * or {@link #MultipartStream(InputStream, byte[], int,
0266:             * org.apache.commons.fileupload.MultipartStream.ProgressNotifier)}
0267:             */
0268:            public MultipartStream() {
0269:                this (null, null, null);
0270:            }
0271:
0272:            /**
0273:             * <p> Constructs a <code>MultipartStream</code> with a custom size buffer
0274:             * and no progress notifier.
0275:             *
0276:             * <p> Note that the buffer must be at least big enough to contain the
0277:             * boundary string, plus 4 characters for CR/LF and double dash, plus at
0278:             * least one byte of data.  Too small a buffer size setting will degrade
0279:             * performance.
0280:             *
0281:             * @param input    The <code>InputStream</code> to serve as a data source.
0282:             * @param boundary The token used for dividing the stream into
0283:             *                 <code>encapsulations</code>.
0284:             * @param bufSize  The size of the buffer to be used, in bytes.
0285:             *
0286:             * @see #MultipartStream(InputStream, byte[], ProgressNotifier)
0287:             * @deprecated Use {@link #MultipartStream(InputStream, byte[], int,
0288:             *  org.apache.commons.fileupload.MultipartStream.ProgressNotifier)}.
0289:             */
0290:            public MultipartStream(InputStream input, byte[] boundary,
0291:                    int bufSize) {
0292:                this (input, boundary, bufSize, null);
0293:            }
0294:
0295:            /**
0296:             * <p> Constructs a <code>MultipartStream</code> with a custom size buffer.
0297:             *
0298:             * <p> Note that the buffer must be at least big enough to contain the
0299:             * boundary string, plus 4 characters for CR/LF and double dash, plus at
0300:             * least one byte of data.  Too small a buffer size setting will degrade
0301:             * performance.
0302:             *
0303:             * @param input    The <code>InputStream</code> to serve as a data source.
0304:             * @param boundary The token used for dividing the stream into
0305:             *                 <code>encapsulations</code>.
0306:             * @param bufSize  The size of the buffer to be used, in bytes.
0307:             * @param pNotifier The notifier, which is used for calling the
0308:             *                  progress listener, if any.
0309:             *
0310:             * @see #MultipartStream(InputStream, byte[], ProgressNotifier)
0311:             */
0312:            MultipartStream(InputStream input, byte[] boundary, int bufSize,
0313:                    ProgressNotifier pNotifier) {
0314:                this .input = input;
0315:                this .bufSize = bufSize;
0316:                this .buffer = new byte[bufSize];
0317:                this .notifier = pNotifier;
0318:
0319:                // We prepend CR/LF to the boundary to chop trailng CR/LF from
0320:                // body-data tokens.
0321:                this .boundary = new byte[boundary.length
0322:                        + BOUNDARY_PREFIX.length];
0323:                this .boundaryLength = boundary.length + BOUNDARY_PREFIX.length;
0324:                this .keepRegion = boundary.length + KEEP_REGION_PAD;
0325:                System.arraycopy(BOUNDARY_PREFIX, 0, this .boundary, 0,
0326:                        BOUNDARY_PREFIX.length);
0327:                System.arraycopy(boundary, 0, this .boundary,
0328:                        BOUNDARY_PREFIX.length, boundary.length);
0329:
0330:                head = 0;
0331:                tail = 0;
0332:            }
0333:
0334:            /**
0335:             * <p> Constructs a <code>MultipartStream</code> with a default size buffer.
0336:             *
0337:             * @param input    The <code>InputStream</code> to serve as a data source.
0338:             * @param boundary The token used for dividing the stream into
0339:             *                 <code>encapsulations</code>.
0340:             * @param pNotifier An object for calling the progress listener, if any.
0341:             *
0342:             *
0343:             * @see #MultipartStream(InputStream, byte[], int, ProgressNotifier)
0344:             */
0345:            MultipartStream(InputStream input, byte[] boundary,
0346:                    ProgressNotifier pNotifier) {
0347:                this (input, boundary, DEFAULT_BUFSIZE, pNotifier);
0348:            }
0349:
0350:            /**
0351:             * <p> Constructs a <code>MultipartStream</code> with a default size buffer.
0352:             *
0353:             * @param input    The <code>InputStream</code> to serve as a data source.
0354:             * @param boundary The token used for dividing the stream into
0355:             *                 <code>encapsulations</code>.
0356:             *
0357:             * @deprecated Use {@link #MultipartStream(InputStream, byte[],
0358:             *  ProgressNotifier)}.
0359:             * @see #MultipartStream(InputStream, byte[], int, ProgressNotifier)
0360:             */
0361:            public MultipartStream(InputStream input, byte[] boundary) {
0362:                this (input, boundary, DEFAULT_BUFSIZE, null);
0363:            }
0364:
0365:            // --------------------------------------------------------- Public methods
0366:
0367:            /**
0368:             * Retrieves the character encoding used when reading the headers of an
0369:             * individual part. When not specified, or <code>null</code>, the platform
0370:             * default encoding is used.
0371:
0372:             *
0373:             * @return The encoding used to read part headers.
0374:             */
0375:            public String getHeaderEncoding() {
0376:                return headerEncoding;
0377:            }
0378:
0379:            /**
0380:             * Specifies the character encoding to be used when reading the headers of
0381:             * individual parts. When not specified, or <code>null</code>, the platform
0382:             * default encoding is used.
0383:             *
0384:             * @param encoding The encoding used to read part headers.
0385:             */
0386:            public void setHeaderEncoding(String encoding) {
0387:                headerEncoding = encoding;
0388:            }
0389:
0390:            /**
0391:             * Reads a byte from the <code>buffer</code>, and refills it as
0392:             * necessary.
0393:             *
0394:             * @return The next byte from the input stream.
0395:             *
0396:             * @throws IOException if there is no more data available.
0397:             */
0398:            public byte readByte() throws IOException {
0399:                // Buffer depleted ?
0400:                if (head == tail) {
0401:                    head = 0;
0402:                    // Refill.
0403:                    tail = input.read(buffer, head, bufSize);
0404:                    if (tail == -1) {
0405:                        // No more data available.
0406:                        throw new IOException("No more data is available");
0407:                    }
0408:                    notifier.noteBytesRead(tail);
0409:                }
0410:                return buffer[head++];
0411:            }
0412:
0413:            /**
0414:             * Skips a <code>boundary</code> token, and checks whether more
0415:             * <code>encapsulations</code> are contained in the stream.
0416:             *
0417:             * @return <code>true</code> if there are more encapsulations in
0418:             *         this stream; <code>false</code> otherwise.
0419:             *
0420:             * @throws MalformedStreamException if the stream ends unexpecetedly or
0421:             *                                  fails to follow required syntax.
0422:             */
0423:            public boolean readBoundary() throws MalformedStreamException {
0424:                byte[] marker = new byte[2];
0425:                boolean nextChunk = false;
0426:
0427:                head += boundaryLength;
0428:                try {
0429:                    marker[0] = readByte();
0430:                    if (marker[0] == LF) {
0431:                        // Work around IE5 Mac bug with input type=image.
0432:                        // Because the boundary delimiter, not including the trailing
0433:                        // CRLF, must not appear within any file (RFC 2046, section
0434:                        // 5.1.1), we know the missing CR is due to a buggy browser
0435:                        // rather than a file containing something similar to a
0436:                        // boundary.
0437:                        return true;
0438:                    }
0439:
0440:                    marker[1] = readByte();
0441:                    if (arrayequals(marker, STREAM_TERMINATOR, 2)) {
0442:                        nextChunk = false;
0443:                    } else if (arrayequals(marker, FIELD_SEPARATOR, 2)) {
0444:                        nextChunk = true;
0445:                    } else {
0446:                        throw new MalformedStreamException(
0447:                                "Unexpected characters follow a boundary");
0448:                    }
0449:                } catch (IOException e) {
0450:                    throw new MalformedStreamException(
0451:                            "Stream ended unexpectedly");
0452:                }
0453:                return nextChunk;
0454:            }
0455:
0456:            /**
0457:             * <p>Changes the boundary token used for partitioning the stream.
0458:             *
0459:             * <p>This method allows single pass processing of nested multipart
0460:             * streams.
0461:             *
0462:             * <p>The boundary token of the nested stream is <code>required</code>
0463:             * to be of the same length as the boundary token in parent stream.
0464:             *
0465:             * <p>Restoring the parent stream boundary token after processing of a
0466:             * nested stream is left to the application.
0467:             *
0468:             * @param boundary The boundary to be used for parsing of the nested
0469:             *                 stream.
0470:             *
0471:             * @throws IllegalBoundaryException if the <code>boundary</code>
0472:             *                                  has a different length than the one
0473:             *                                  being currently parsed.
0474:             */
0475:            public void setBoundary(byte[] boundary)
0476:                    throws IllegalBoundaryException {
0477:                if (boundary.length != boundaryLength - BOUNDARY_PREFIX.length) {
0478:                    throw new IllegalBoundaryException(
0479:                            "The length of a boundary token can not be changed");
0480:                }
0481:                System.arraycopy(boundary, 0, this .boundary,
0482:                        BOUNDARY_PREFIX.length, boundary.length);
0483:            }
0484:
0485:            /**
0486:             * <p>Reads the <code>header-part</code> of the current
0487:             * <code>encapsulation</code>.
0488:             *
0489:             * <p>Headers are returned verbatim to the input stream, including the
0490:             * trailing <code>CRLF</code> marker. Parsing is left to the
0491:             * application.
0492:             *
0493:             * <p><strong>TODO</strong> allow limiting maximum header size to
0494:             * protect against abuse.
0495:             *
0496:             * @return The <code>header-part</code> of the current encapsulation.
0497:             *
0498:             * @throws MalformedStreamException if the stream ends unexpecetedly.
0499:             */
0500:            public String readHeaders() throws MalformedStreamException {
0501:                int i = 0;
0502:                byte[] b = new byte[1];
0503:                // to support multi-byte characters
0504:                ByteArrayOutputStream baos = new ByteArrayOutputStream();
0505:                int sizeMax = HEADER_PART_SIZE_MAX;
0506:                int size = 0;
0507:                while (i < HEADER_SEPARATOR.length) {
0508:                    try {
0509:                        b[0] = readByte();
0510:                    } catch (IOException e) {
0511:                        throw new MalformedStreamException(
0512:                                "Stream ended unexpectedly");
0513:                    }
0514:                    size++;
0515:                    if (b[0] == HEADER_SEPARATOR[i]) {
0516:                        i++;
0517:                    } else {
0518:                        i = 0;
0519:                    }
0520:                    if (size <= sizeMax) {
0521:                        baos.write(b[0]);
0522:                    }
0523:                }
0524:
0525:                String headers = null;
0526:                if (headerEncoding != null) {
0527:                    try {
0528:                        headers = baos.toString(headerEncoding);
0529:                    } catch (UnsupportedEncodingException e) {
0530:                        // Fall back to platform default if specified encoding is not
0531:                        // supported.
0532:                        headers = baos.toString();
0533:                    }
0534:                } else {
0535:                    headers = baos.toString();
0536:                }
0537:
0538:                return headers;
0539:            }
0540:
0541:            /**
0542:             * <p>Reads <code>body-data</code> from the current
0543:             * <code>encapsulation</code> and writes its contents into the
0544:             * output <code>Stream</code>.
0545:             *
0546:             * <p>Arbitrary large amounts of data can be processed by this
0547:             * method using a constant size buffer. (see {@link
0548:             * #MultipartStream(InputStream,byte[],int, ProgressNotifier) constructor}).
0549:             *
0550:             * @param output The <code>Stream</code> to write data into. May
0551:             *               be null, in which case this method is equivalent
0552:             *               to {@link #discardBodyData()}.
0553:             *
0554:             * @return the amount of data written.
0555:             *
0556:             * @throws MalformedStreamException if the stream ends unexpectedly.
0557:             * @throws IOException              if an i/o error occurs.
0558:             */
0559:            public int readBodyData(OutputStream output)
0560:                    throws MalformedStreamException, IOException {
0561:                final InputStream istream = newInputStream();
0562:                return (int) Streams.copy(istream, output, false);
0563:            }
0564:
0565:            /**
0566:             * Creates a new {@link ItemInputStream}.
0567:             * @return A new instance of {@link ItemInputStream}.
0568:             */
0569:            ItemInputStream newInputStream() {
0570:                return new ItemInputStream();
0571:            }
0572:
0573:            /**
0574:             * <p> Reads <code>body-data</code> from the current
0575:             * <code>encapsulation</code> and discards it.
0576:             *
0577:             * <p>Use this method to skip encapsulations you don't need or don't
0578:             * understand.
0579:             *
0580:             * @return The amount of data discarded.
0581:             *
0582:             * @throws MalformedStreamException if the stream ends unexpectedly.
0583:             * @throws IOException              if an i/o error occurs.
0584:             */
0585:            public int discardBodyData() throws MalformedStreamException,
0586:                    IOException {
0587:                return readBodyData(null);
0588:            }
0589:
0590:            /**
0591:             * Finds the beginning of the first <code>encapsulation</code>.
0592:             *
0593:             * @return <code>true</code> if an <code>encapsulation</code> was found in
0594:             *         the stream.
0595:             *
0596:             * @throws IOException if an i/o error occurs.
0597:             */
0598:            public boolean skipPreamble() throws IOException {
0599:                // First delimiter may be not preceeded with a CRLF.
0600:                System.arraycopy(boundary, 2, boundary, 0, boundary.length - 2);
0601:                boundaryLength = boundary.length - 2;
0602:                try {
0603:                    // Discard all data up to the delimiter.
0604:                    discardBodyData();
0605:
0606:                    // Read boundary - if succeded, the stream contains an
0607:                    // encapsulation.
0608:                    return readBoundary();
0609:                } catch (MalformedStreamException e) {
0610:                    return false;
0611:                } finally {
0612:                    // Restore delimiter.
0613:                    System.arraycopy(boundary, 0, boundary, 2,
0614:                            boundary.length - 2);
0615:                    boundaryLength = boundary.length;
0616:                    boundary[0] = CR;
0617:                    boundary[1] = LF;
0618:                }
0619:            }
0620:
0621:            /**
0622:             * Compares <code>count</code> first bytes in the arrays
0623:             * <code>a</code> and <code>b</code>.
0624:             *
0625:             * @param a     The first array to compare.
0626:             * @param b     The second array to compare.
0627:             * @param count How many bytes should be compared.
0628:             *
0629:             * @return <code>true</code> if <code>count</code> first bytes in arrays
0630:             *         <code>a</code> and <code>b</code> are equal.
0631:             */
0632:            public static boolean arrayequals(byte[] a, byte[] b, int count) {
0633:                for (int i = 0; i < count; i++) {
0634:                    if (a[i] != b[i]) {
0635:                        return false;
0636:                    }
0637:                }
0638:                return true;
0639:            }
0640:
0641:            /**
0642:             * Searches for a byte of specified value in the <code>buffer</code>,
0643:             * starting at the specified <code>position</code>.
0644:             *
0645:             * @param value The value to find.
0646:             * @param pos   The starting position for searching.
0647:             *
0648:             * @return The position of byte found, counting from beginning of the
0649:             *         <code>buffer</code>, or <code>-1</code> if not found.
0650:             */
0651:            protected int findByte(byte value, int pos) {
0652:                for (int i = pos; i < tail; i++) {
0653:                    if (buffer[i] == value) {
0654:                        return i;
0655:                    }
0656:                }
0657:
0658:                return -1;
0659:            }
0660:
0661:            /**
0662:             * Searches for the <code>boundary</code> in the <code>buffer</code>
0663:             * region delimited by <code>head</code> and <code>tail</code>.
0664:             *
0665:             * @return The position of the boundary found, counting from the
0666:             *         beginning of the <code>buffer</code>, or <code>-1</code> if
0667:             *         not found.
0668:             */
0669:            protected int findSeparator() {
0670:                int first;
0671:                int match = 0;
0672:                int maxpos = tail - boundaryLength;
0673:                for (first = head; (first <= maxpos)
0674:                        && (match != boundaryLength); first++) {
0675:                    first = findByte(boundary[0], first);
0676:                    if (first == -1 || (first > maxpos)) {
0677:                        return -1;
0678:                    }
0679:                    for (match = 1; match < boundaryLength; match++) {
0680:                        if (buffer[first + match] != boundary[match]) {
0681:                            break;
0682:                        }
0683:                    }
0684:                }
0685:                if (match == boundaryLength) {
0686:                    return first - 1;
0687:                }
0688:                return -1;
0689:            }
0690:
0691:            /**
0692:             * Thrown to indicate that the input stream fails to follow the
0693:             * required syntax.
0694:             */
0695:            public static class MalformedStreamException extends IOException {
0696:                /**
0697:                 * Constructs a <code>MalformedStreamException</code> with no
0698:                 * detail message.
0699:                 */
0700:                public MalformedStreamException() {
0701:                    super ();
0702:                }
0703:
0704:                /**
0705:                 * Constructs an <code>MalformedStreamException</code> with
0706:                 * the specified detail message.
0707:                 *
0708:                 * @param message The detail message.
0709:                 */
0710:                public MalformedStreamException(String message) {
0711:                    super (message);
0712:                }
0713:            }
0714:
0715:            /**
0716:             * Thrown upon attempt of setting an invalid boundary token.
0717:             */
0718:            public static class IllegalBoundaryException extends IOException {
0719:                /**
0720:                 * Constructs an <code>IllegalBoundaryException</code> with no
0721:                 * detail message.
0722:                 */
0723:                public IllegalBoundaryException() {
0724:                    super ();
0725:                }
0726:
0727:                /**
0728:                 * Constructs an <code>IllegalBoundaryException</code> with
0729:                 * the specified detail message.
0730:                 *
0731:                 * @param message The detail message.
0732:                 */
0733:                public IllegalBoundaryException(String message) {
0734:                    super (message);
0735:                }
0736:            }
0737:
0738:            /**
0739:             * An {@link InputStream} for reading an items contents.
0740:             */
0741:            public class ItemInputStream extends InputStream implements 
0742:                    Closeable {
0743:                /** The number of bytes, which have been read so far.
0744:                 */
0745:                private long total;
0746:                /** The number of bytes, which must be hold, because
0747:                 * they might be a part of the boundary.
0748:                 */
0749:                private int pad;
0750:                /** The current offset in the buffer.
0751:                 */
0752:                private int pos;
0753:                /** Whether the stream is already closed.
0754:                 */
0755:                private boolean closed;
0756:
0757:                /**
0758:                 * Creates a new instance.
0759:                 */
0760:                ItemInputStream() {
0761:                    findSeparator();
0762:                }
0763:
0764:                /**
0765:                 * Called for finding the separator.
0766:                 */
0767:                private void findSeparator() {
0768:                    pos = MultipartStream.this .findSeparator();
0769:                    if (pos == -1) {
0770:                        if (tail - head > keepRegion) {
0771:                            pad = keepRegion;
0772:                        } else {
0773:                            pad = tail - head;
0774:                        }
0775:                    }
0776:                }
0777:
0778:                /**
0779:                 * Returns the number of bytes, which have been read
0780:                 * by the stream.
0781:                 * @return Number of bytes, which have been read so far.
0782:                 */
0783:                public long getBytesRead() {
0784:                    return total;
0785:                }
0786:
0787:                /**
0788:                 * Returns the number of bytes, which are currently
0789:                 * available, without blocking.
0790:                 * @throws IOException An I/O error occurs.
0791:                 * @return Number of bytes in the buffer.
0792:                 */
0793:                public int available() throws IOException {
0794:                    if (pos == -1) {
0795:                        return tail - head - pad;
0796:                    }
0797:                    return pos - head;
0798:                }
0799:
0800:                /** Offset when converting negative bytes to integers.
0801:                 */
0802:                private static final int BYTE_POSITIVE_OFFSET = 256;
0803:
0804:                /**
0805:                 * Returns the next byte in the stream.
0806:                 * @return The next byte in the stream, as a non-negative
0807:                 *   integer, or -1 for EOF.
0808:                 * @throws IOException An I/O error occurred.
0809:                 */
0810:                public int read() throws IOException {
0811:                    if (closed) {
0812:                        throw new FileItemStream.ItemSkippedException();
0813:                    }
0814:                    if (available() == 0) {
0815:                        if (makeAvailable() == 0) {
0816:                            return -1;
0817:                        }
0818:                    }
0819:                    ++total;
0820:                    int b = buffer[head++];
0821:                    if (b >= 0) {
0822:                        return b;
0823:                    }
0824:                    return b + BYTE_POSITIVE_OFFSET;
0825:                }
0826:
0827:                /**
0828:                 * Reads bytes into the given buffer.
0829:                 * @param b The destination buffer, where to write to.
0830:                 * @param off Offset of the first byte in the buffer.
0831:                 * @param len Maximum number of bytes to read.
0832:                 * @return Number of bytes, which have been actually read,
0833:                 *   or -1 for EOF.
0834:                 * @throws IOException An I/O error occurred.
0835:                 */
0836:                public int read(byte[] b, int off, int len) throws IOException {
0837:                    if (closed) {
0838:                        throw new FileItemStream.ItemSkippedException();
0839:                    }
0840:                    if (len == 0) {
0841:                        return 0;
0842:                    }
0843:                    int res = available();
0844:                    if (res == 0) {
0845:                        res = makeAvailable();
0846:                        if (res == 0) {
0847:                            return -1;
0848:                        }
0849:                    }
0850:                    res = Math.min(res, len);
0851:                    System.arraycopy(buffer, head, b, off, res);
0852:                    head += res;
0853:                    total += res;
0854:                    return res;
0855:                }
0856:
0857:                /**
0858:                 * Closes the input stream.
0859:                 * @throws IOException An I/O error occurred.
0860:                 */
0861:                public void close() throws IOException {
0862:                    if (closed) {
0863:                        return;
0864:                    }
0865:                    for (;;) {
0866:                        int av = available();
0867:                        if (av == 0) {
0868:                            av = makeAvailable();
0869:                            if (av == 0) {
0870:                                break;
0871:                            }
0872:                        }
0873:                        skip(av);
0874:                    }
0875:                    closed = true;
0876:                }
0877:
0878:                /**
0879:                 * Skips the given number of bytes.
0880:                 * @param bytes Number of bytes to skip.
0881:                 * @return The number of bytes, which have actually been
0882:                 *   skipped.
0883:                 * @throws IOException An I/O error occurred.
0884:                 */
0885:                public long skip(long bytes) throws IOException {
0886:                    if (closed) {
0887:                        throw new FileItemStream.ItemSkippedException();
0888:                    }
0889:                    int av = available();
0890:                    if (av == 0) {
0891:                        av = makeAvailable();
0892:                        if (av == 0) {
0893:                            return 0;
0894:                        }
0895:                    }
0896:                    long res = Math.min(av, bytes);
0897:                    head += res;
0898:                    return res;
0899:                }
0900:
0901:                /**
0902:                 * Attempts to read more data.
0903:                 * @return Number of available bytes
0904:                 * @throws IOException An I/O error occurred.
0905:                 */
0906:                private int makeAvailable() throws IOException {
0907:                    if (pos != -1) {
0908:                        return 0;
0909:                    }
0910:
0911:                    // Move the data to the beginning of the buffer.
0912:                    total += tail - head - pad;
0913:                    System.arraycopy(buffer, tail - pad, buffer, 0, pad);
0914:
0915:                    // Refill buffer with new data.
0916:                    head = 0;
0917:                    int bytesRead = input.read(buffer, pad, bufSize - pad);
0918:                    if (bytesRead == -1) {
0919:                        // The last pad amount is left in the buffer.
0920:                        // Boundary can't be in there so signal an error
0921:                        // condition.
0922:                        throw new MalformedStreamException(
0923:                                "Stream ended unexpectedly");
0924:                    }
0925:                    notifier.noteBytesRead(bytesRead);
0926:                    tail = pad + bytesRead;
0927:                    findSeparator();
0928:                    return available();
0929:                }
0930:
0931:                /**
0932:                 * Returns, whether the stream is closed.
0933:                 * @return True, if the stream is closed, otherwise false.
0934:                 */
0935:                public boolean isClosed() {
0936:                    return closed;
0937:                }
0938:            }
0939:
0940:            // ------------------------------------------------------ Debugging methods
0941:
0942:            // These are the methods that were used to debug this stuff.
0943:            /*
0944:
0945:            // Dump data.
0946:            protected void dump()
0947:            {
0948:                System.out.println("01234567890");
0949:                byte[] temp = new byte[buffer.length];
0950:                for(int i=0; i<buffer.length; i++)
0951:                {
0952:                    if (buffer[i] == 0x0D || buffer[i] == 0x0A)
0953:                    {
0954:                        temp[i] = 0x21;
0955:                    }
0956:                    else
0957:                    {
0958:                        temp[i] = buffer[i];
0959:                    }
0960:                }
0961:                System.out.println(new String(temp));
0962:                int i;
0963:                for (i=0; i<head; i++)
0964:                    System.out.print(" ");
0965:                System.out.println("h");
0966:                for (i=0; i<tail; i++)
0967:                    System.out.print(" ");
0968:                System.out.println("t");
0969:                System.out.flush();
0970:            }
0971:
0972:            // Main routine, for testing purposes only.
0973:            //
0974:            // @param args A String[] with the command line arguments.
0975:            // @throws Exception, a generic exception.
0976:            public static void main( String[] args )
0977:                throws Exception
0978:            {
0979:                File boundaryFile = new File("boundary.dat");
0980:                int boundarySize = (int)boundaryFile.length();
0981:                byte[] boundary = new byte[boundarySize];
0982:                FileInputStream input = new FileInputStream(boundaryFile);
0983:                input.read(boundary,0,boundarySize);
0984:
0985:                input = new FileInputStream("multipart.dat");
0986:                MultipartStream chunks = new MultipartStream(input, boundary);
0987:
0988:                int i = 0;
0989:                String header;
0990:                OutputStream output;
0991:                boolean nextChunk = chunks.skipPreamble();
0992:                while (nextChunk)
0993:                {
0994:                    header = chunks.readHeaders();
0995:                    System.out.println("!"+header+"!");
0996:                    System.out.println("wrote part"+i+".dat");
0997:                    output = new FileOutputStream("part"+(i++)+".dat");
0998:                    chunks.readBodyData(output);
0999:                    nextChunk = chunks.readBoundary();
1000:                }
1001:            }
1002:
1003:             */
1004:        }
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