Java tutorial
/* * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0.1/httpcore/src/main/java/org/apache/http/impl/io/AbstractSessionInputBuffer.java $ * $Revision: 744526 $ * $Date: 2009-02-14 18:04:18 +0100 (Sat, 14 Feb 2009) $ * * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * ==================================================================== * * 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/>. * */ package org.vietspider.net.apache; import java.io.IOException; import java.io.InputStream; import org.apache.http.impl.io.HttpTransportMetricsImpl; import org.apache.http.io.HttpTransportMetrics; import org.apache.http.io.SessionInputBuffer; import org.apache.http.params.CoreConnectionPNames; import org.apache.http.params.HttpParams; import org.apache.http.params.HttpProtocolParams; import org.apache.http.protocol.HTTP; import org.apache.http.util.ByteArrayBuffer; import org.apache.http.util.CharArrayBuffer; /** * Abstract base class for session input buffers that stream data from * an arbitrary {@link InputStream}. This class buffers input data in * an internal byte array for optimal input performance. * <p> * {@link #readLine(CharArrayBuffer)} and {@link #readLine()} methods of this * class treat a lone LF as valid line delimiters in addition to CR-LF required * by the HTTP specification. * * @since 4.0 */ public abstract class AbstractSessionInputBuffer implements SessionInputBuffer { private InputStream instream; private byte[] buffer; private int bufferpos; private int bufferlen; private ByteArrayBuffer linebuffer = null; private String charset = HTTP.US_ASCII; private boolean ascii = true; private int maxLineLen = -1; // private boolean timeoutSocket; private HttpTransportMetricsImpl metrics; protected void init(final InputStream _instream, int buffersize, final HttpParams params) { if (_instream == null) { throw new IllegalArgumentException("Input stream may not be null"); } if (buffersize <= 0) { throw new IllegalArgumentException("Buffer size may not be negative or zero"); } if (params == null) { throw new IllegalArgumentException("HTTP parameters may not be null"); } this.instream = _instream; this.buffer = new byte[buffersize]; this.bufferpos = 0; this.bufferlen = 0; this.linebuffer = new ByteArrayBuffer(buffersize); this.charset = HttpProtocolParams.getHttpElementCharset(params); // this.timeoutSocket = params.getBooleanParameter("vietspider.socket.timeout", false); this.ascii = this.charset.equalsIgnoreCase(HTTP.US_ASCII) || this.charset.equalsIgnoreCase(HTTP.ASCII); this.maxLineLen = params.getIntParameter(CoreConnectionPNames.MAX_LINE_LENGTH, -1); this.metrics = new HttpTransportMetricsImpl(); } protected int fillBuffer() throws IOException { if (this.bufferpos > 0) { int len = this.bufferlen - this.bufferpos; if (len > 0) { System.arraycopy(this.buffer, this.bufferpos, this.buffer, 0, len); } this.bufferpos = 0; this.bufferlen = len; } int l; int off = this.bufferlen; int len = this.buffer.length - off; l = this.instream.read(this.buffer, off, len); if (l == -1) return -1; this.bufferlen = off + l; this.metrics.incrementBytesTransferred(l); return l; } protected boolean hasBufferedData() { return this.bufferpos < this.bufferlen; } public int read() throws IOException { int noRead = 0; while (!hasBufferedData()) { noRead = fillBuffer(); if (noRead == -1) return -1; } return this.buffer[this.bufferpos++] & 0xff; } public int read(final byte[] b, int off, int len) throws IOException { if (b == null) return 0; int noRead = 0; while (!hasBufferedData()) { noRead = fillBuffer(); if (noRead == -1) return -1; } int chunk = this.bufferlen - this.bufferpos; if (chunk > len) chunk = len; System.arraycopy(this.buffer, this.bufferpos, b, off, chunk); this.bufferpos += chunk; return chunk; } public int read(final byte[] b) throws IOException { return (b == null) ? 0 : read(b, 0, b.length); } private int locateLF() { for (int i = this.bufferpos; i < this.bufferlen; i++) { if (this.buffer[i] == HTTP.LF) return i; } return -1; } public int readLine(final CharArrayBuffer charbuffer) throws IOException { if (charbuffer == null) { throw new IllegalArgumentException("Char array buffer may not be null"); } this.linebuffer.clear(); int noRead = 0; // HeaderReaderTimer2 timer = new HeaderReaderTimer2(instream); boolean retry = true; // try { // if(timeoutSocket) new Thread(timer).start(); // while (timer.isLive()) { while (retry) { // attempt to find end of line (LF) int i = locateLF(); if (i != -1) { // end of line found. if (this.linebuffer.isEmpty()) { // the entire line is preset in the read buffer return lineFromReadBuffer(charbuffer, i); } retry = false; // timer.closeTimer(); int len = i + 1 - this.bufferpos; this.linebuffer.append(this.buffer, this.bufferpos, len); this.bufferpos = i + 1; } else { // end of line not found if (hasBufferedData()) { int len = this.bufferlen - this.bufferpos; this.linebuffer.append(this.buffer, this.bufferpos, len); this.bufferpos = this.bufferlen; } noRead = fillBuffer(); if (noRead == -1) retry = false;/*timer.closeTimer(); */ } if (this.maxLineLen > 0 && this.linebuffer.length() >= this.maxLineLen) { throw new IOException("Maximum line length limit exceeded"); } } // } finally { // timer.closeTimer(); // } if (noRead == -1 && this.linebuffer.isEmpty()) return -1; return lineFromLineBuffer(charbuffer); } private int lineFromLineBuffer(final CharArrayBuffer charbuffer) throws IOException { // discard LF if found int l = this.linebuffer.length(); if (l > 0) { if (this.linebuffer.byteAt(l - 1) == HTTP.LF) { l--; this.linebuffer.setLength(l); } // discard CR if found if (l > 0) { if (this.linebuffer.byteAt(l - 1) == HTTP.CR) { l--; this.linebuffer.setLength(l); } } } l = this.linebuffer.length(); if (this.ascii) { charbuffer.append(this.linebuffer, 0, l); } else { String s = new String(this.linebuffer.buffer(), 0, l, this.charset); charbuffer.append(s); } return l; } private int lineFromReadBuffer(final CharArrayBuffer charbuffer, int pos) throws IOException { int off = this.bufferpos; int len; this.bufferpos = pos + 1; if (pos > 0 && this.buffer[pos - 1] == HTTP.CR) { // skip CR if found pos--; } len = pos - off; if (this.ascii) { charbuffer.append(this.buffer, off, len); } else { String s = new String(this.buffer, off, len, this.charset); charbuffer.append(s); } return len; } public String readLine() throws IOException { CharArrayBuffer charbuffer = new CharArrayBuffer(64); int l = readLine(charbuffer); return (l != -1) ? charbuffer.toString() : null; } public HttpTransportMetrics getMetrics() { return this.metrics; } }