1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/impl/io/AbstractMessageParser.java $ 3 * $Revision: 576077 $ 4 * $Date: 2007-09-16 04:50:22 -0700 (Sun, 16 Sep 2007) $ 5 * 6 * ==================================================================== 7 * Licensed to the Apache Software Foundation (ASF) under one 8 * or more contributor license agreements. See the NOTICE file 9 * distributed with this work for additional information 10 * regarding copyright ownership. The ASF licenses this file 11 * to you under the Apache License, Version 2.0 (the 12 * "License"); you may not use this file except in compliance 13 * with the License. You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, 18 * software distributed under the License is distributed on an 19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 20 * KIND, either express or implied. See the License for the 21 * specific language governing permissions and limitations 22 * under the License. 23 * ==================================================================== 24 * 25 * This software consists of voluntary contributions made by many 26 * individuals on behalf of the Apache Software Foundation. For more 27 * information on the Apache Software Foundation, please see 28 * <http://www.apache.org/>. 29 * 30 */ 31 32 package org.apache.http.impl.io; 33 34 import java.io.IOException; 35 import java.util.ArrayList; 36 37 import org.apache.http.Header; 38 import org.apache.http.HttpException; 39 import org.apache.http.HttpMessage; 40 import org.apache.http.ParseException; 41 import org.apache.http.ProtocolException; 42 import org.apache.http.io.HttpMessageParser; 43 import org.apache.http.io.SessionInputBuffer; 44 import org.apache.http.message.LineParser; 45 import org.apache.http.message.BasicLineParser; 46 import org.apache.http.params.CoreConnectionPNames; 47 import org.apache.http.params.HttpParams; 48 import org.apache.http.util.CharArrayBuffer; 49 50 /** 51 * Message parser base class. 52 * 53 * @author Michael Becke 54 * @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a> 55 */ 56 public abstract class AbstractMessageParser implements HttpMessageParser { 57 58 private final SessionInputBuffer sessionBuffer; 59 private final int maxHeaderCount; 60 private final int maxLineLen; 61 protected final LineParser lineParser; 62 63 64 public AbstractMessageParser( 65 final SessionInputBuffer buffer, 66 final LineParser parser, 67 final HttpParams params) { 68 super(); 69 if (buffer == null) { 70 throw new IllegalArgumentException("Session input buffer may not be null"); 71 } 72 if (params == null) { 73 throw new IllegalArgumentException("HTTP parameters may not be null"); 74 } 75 this.sessionBuffer = buffer; 76 this.maxHeaderCount = params.getIntParameter( 77 CoreConnectionPNames.MAX_HEADER_COUNT, -1); 78 this.maxLineLen = params.getIntParameter( 79 CoreConnectionPNames.MAX_LINE_LENGTH, -1); 80 this.lineParser = (parser != null) ? parser : BasicLineParser.DEFAULT; 81 } 82 83 /** 84 * Parses HTTP headers from the data receiver stream according to the generic 85 * format as given in Section 3.1 of RFC 822, RFC-2616 Section 4 and 19.3. 86 * 87 * @param inbuffer Session input buffer 88 * @param maxHeaderCount maximum number of headers allowed. If the number 89 * of headers received from the data stream exceeds maxCount value, an 90 * IOException will be thrown. Setting this parameter to a negative value 91 * or zero will disable the check. 92 * @param maxLineLen maximum number of characters for a header line, 93 * including the continuation lines 94 * @return array of HTTP headers 95 * 96 * @throws HttpException 97 * @throws IOException 98 */ 99 public static Header[] parseHeaders( 100 final SessionInputBuffer inbuffer, 101 int maxHeaderCount, 102 int maxLineLen, 103 LineParser parser) 104 throws HttpException, IOException { 105 106 if (inbuffer == null) { 107 throw new IllegalArgumentException("Session input buffer may not be null"); 108 } 109 if (parser == null) 110 parser = BasicLineParser.DEFAULT; 111 112 ArrayList headerLines = new ArrayList(); 113 114 CharArrayBuffer current = null; 115 CharArrayBuffer previous = null; 116 for (;;) { 117 if (current == null) { 118 current = new CharArrayBuffer(64); 119 } else { 120 current.clear(); 121 } 122 int l = inbuffer.readLine(current); 123 if (l == -1 || current.length() < 1) { 124 break; 125 } 126 // Parse the header name and value 127 // Check for folded headers first 128 // Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2 129 // discussion on folded headers 130 if ((current.charAt(0) == ' ' || current.charAt(0) == '\t') && previous != null) { 131 // we have continuation folded header 132 // so append value 133 int i = 0; 134 while (i < current.length()) { 135 char ch = current.charAt(i); 136 if (ch != ' ' && ch != '\t') { 137 break; 138 } 139 i++; 140 } 141 if (maxLineLen > 0 142 && previous.length() + 1 + current.length() - i > maxLineLen) { 143 throw new IOException("Maximum line length limit exceeded"); 144 } 145 previous.append(' '); 146 previous.append(current, i, current.length() - i); 147 } else { 148 headerLines.add(current); 149 previous = current; 150 current = null; 151 } 152 if (maxHeaderCount > 0 && headerLines.size() >= maxHeaderCount) { 153 throw new IOException("Maximum header count exceeded"); 154 } 155 } 156 Header[] headers = new Header[headerLines.size()]; 157 for (int i = 0; i < headerLines.size(); i++) { 158 CharArrayBuffer buffer = (CharArrayBuffer) headerLines.get(i); 159 try { 160 headers[i] = parser.parseHeader(buffer); 161 } catch (ParseException ex) { 162 throw new ProtocolException(ex.getMessage()); 163 } 164 } 165 return headers; 166 } 167 168 protected abstract HttpMessage parseHead(SessionInputBuffer sessionBuffer) 169 throws IOException, HttpException, ParseException; 170 171 public HttpMessage parse() throws IOException, HttpException { 172 HttpMessage message = null; 173 try { 174 message = parseHead(this.sessionBuffer); 175 } catch (ParseException px) { 176 throw new ProtocolException(px.getMessage(), px); 177 } 178 Header[] headers = AbstractMessageParser.parseHeaders( 179 this.sessionBuffer, 180 this.maxHeaderCount, 181 this.maxLineLen, 182 this.lineParser); 183 message.setHeaders(headers); 184 return message; 185 } 186 187 } 188
