Java tutorial
/* * ==================================================================== * * The Apache Software License, Version 1.1 * * Copyright (c) 1999 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowlegement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowlegement may appear in the software itself, * if and wherever such third-party acknowlegements normally appear. * * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * * [Additional notices, if required by prior licensing conditions] * */ package org.apache.jk.common; import java.io.IOException; import java.io.InputStream; import org.apache.jk.core.JkHandler; import org.apache.jk.core.Msg; import org.apache.jk.core.MsgContext; import org.apache.tomcat.util.buf.ByteChunk; /** Generic input stream impl on top of ajp */ public class JkInputStream extends InputStream { private static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory .getLog(JkInputStream.class); public JkInputStream() { } public int available() throws IOException { if (log.isDebugEnabled()) log.debug("available(): " + blen + " " + pos); return blen - pos; } public void close() throws IOException { if (log.isDebugEnabled()) log.debug("cloae() "); this.closed = true; } public void mark(int readLimit) { } public boolean markSupported() { return false; } public void reset() throws IOException { throw new IOException("reset() not supported"); } public int read() throws IOException { if (contentLength == -1) { return doRead1(); } if (available <= 0) { if (log.isDebugEnabled()) log.debug("doRead() nothing available"); return -1; } available--; return doRead1(); } public int read(byte[] b) throws IOException { int rd = read(b, 0, b.length); if (log.isDebugEnabled()) log.debug("read(" + b + ")=" + rd + " / " + b.length); return rd; } public int read(byte[] b, int off, int len) throws IOException { int rd = -1; if (contentLength == -1) { rd = doRead1(b, off, len); return rd; } if (available <= 0) { if (log.isDebugEnabled()) log.debug("doRead() nothing available"); return -1; } rd = doRead1(b, off, len); available -= rd; if (log.isDebugEnabled()) log.debug("Read: " + new String(b, off, len)); return rd; } public long skip(long n) throws IOException { if (n > Integer.MAX_VALUE) { throw new IOException("can't skip than many: " + n); } // XXX if n is big, split this in multiple reads byte[] b = new byte[(int) n]; return read(b, 0, b.length); } // -------------------- Jk specific methods -------------------- Msg bodyMsg = new MsgAjp(); MsgContext mc; // Total length of the body - maximum we can read // If -1, we don't use any limit, and we don't count available int contentLength; // How much remains unread. int available; boolean closed = false; // Ajp13 specific - needs refactoring for the new model public static final int MAX_PACKET_SIZE = 8192; public static final int H_SIZE = 4; // Size of basic packet header public static final int MAX_READ_SIZE = MAX_PACKET_SIZE - H_SIZE - 2; public static final byte JK_AJP13_GET_BODY_CHUNK = 6; // Holds incoming chunks of request body data // XXX We do a copy that could be avoided ! byte[] bodyBuff = new byte[9000]; int blen; // Length of current chunk of body data in buffer int pos; // Current read position within that buffer boolean end_of_stream = false; // true if we've received an empty packet private int doRead1() throws IOException { if (pos >= blen) { if (!refillReadBuffer()) { return -1; } } int i = bodyBuff[pos++] & 0xFF; if (log.isDebugEnabled()) log.debug("doRead1 " + (char) i); return i; // prevent sign extension of byte value } public int doRead1(byte[] b, int off, int len) throws IOException { if (pos >= blen) { if (!refillReadBuffer()) { return -1; } } if (pos + len <= blen) { // Fear the off by one error // Sanity check b.length > off + len? System.arraycopy(bodyBuff, pos, b, off, len); if (log.isDebugEnabled()) log.debug("doRead1: " + pos + " " + len + " " + blen); if (log.isTraceEnabled()) log.trace("Data: \n" + new String(b, off, len)); pos += len; return len; } // Not enough data (blen < pos + len) or chunked encoded int toCopy = len; while (toCopy > 0) { int bytesRemaining = blen - pos; if (bytesRemaining < 0) bytesRemaining = 0; int c = bytesRemaining < toCopy ? bytesRemaining : toCopy; System.arraycopy(bodyBuff, pos, b, off, c); if (log.isDebugEnabled()) log.debug("doRead2: " + pos + " " + len + " " + blen + " " + c); if (log.isTraceEnabled()) log.trace("Data: \n" + new String(b, off, (len < blen - 1) ? len : blen - 1)); toCopy -= c; off += c; pos += c; // In case we exactly consume the buffer if (toCopy > 0) if (!refillReadBuffer()) { // Resets blen and pos break; } } return len - toCopy; } /** Must be called after the request is parsed, before * any input */ public void setContentLength(int i) { contentLength = i; available = i; } /** Must be called when the stream is created */ public void setMsgContext(MsgContext mc) { this.mc = mc; } /** Must be called before or after each request */ public void recycle() { available = 0; blen = 0; pos = 0; closed = false; end_of_stream = false; contentLength = -1; } /** */ public int doRead(ByteChunk responseChunk) throws IOException { if (log.isDebugEnabled()) log.debug("doRead " + pos + " " + blen + " " + available + " " + end_of_stream + " " + responseChunk.getOffset() + " " + responseChunk.getLength()); if (end_of_stream) { return -1; } if (blen == pos) { if (!refillReadBuffer()) { return -1; } } responseChunk.setBytes(bodyBuff, pos, blen); pos = blen; return blen; } /** Receive a chunk of data. Called to implement the * 'special' packet in ajp13 and to receive the data * after we send a GET_BODY packet */ public boolean receive() throws IOException { mc.setType(JkHandler.HANDLE_RECEIVE_PACKET); bodyMsg.reset(); int err = mc.getSource().invoke(bodyMsg, mc); if (log.isDebugEnabled()) log.info("Receiving: getting request body chunk " + err + " " + bodyMsg.getLen()); if (err < 0) { throw new IOException(); } pos = 0; blen = 0; // No data received. if (bodyMsg.getLen() <= 4) { // just the header // Don't mark 'end of stream' for the first chunk. // end_of_stream = true; return false; } blen = bodyMsg.peekInt(); if (blen == 0) { return false; } if (blen > bodyBuff.length) { bodyMsg.dump("Body"); } if (log.isTraceEnabled()) { bodyMsg.dump("Body buffer"); } int cpl = bodyMsg.getBytes(bodyBuff); if (log.isDebugEnabled()) log.debug("Copy into body buffer2 " + bodyBuff + " " + cpl + " " + blen); if (log.isTraceEnabled()) log.trace("Data:\n" + new String(bodyBuff, 0, cpl)); return (blen > 0); } /** * Get more request body data from the web server and store it in the * internal buffer. * * @return true if there is more data, false if not. */ private boolean refillReadBuffer() throws IOException { // If the server returns an empty packet, assume that that end of // the stream has been reached (yuck -- fix protocol??). if (end_of_stream) { if (log.isDebugEnabled()) log.debug("refillReadBuffer: end of stream "); return false; } // Why not use outBuf?? bodyMsg.reset(); bodyMsg.appendByte(JK_AJP13_GET_BODY_CHUNK); bodyMsg.appendInt(MAX_READ_SIZE); if (log.isDebugEnabled()) log.debug("refillReadBuffer " + Thread.currentThread()); mc.setType(JkHandler.HANDLE_SEND_PACKET); mc.getSource().invoke(bodyMsg, mc); // In JNI mode, response will be in bodyMsg. In TCP mode, response need to be // read //bodyMsg.dump("refillReadBuffer "); boolean moreData = receive(); if (!moreData) { end_of_stream = true; } return moreData; } }