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1   /*
2    * ====================================================================
3    * Licensed to the Apache Software Foundation (ASF) under one
4    * or more contributor license agreements.  See the NOTICE file
5    * distributed with this work for additional information
6    * regarding copyright ownership.  The ASF licenses this file
7    * to you under the Apache License, Version 2.0 (the
8    * "License"); you may not use this file except in compliance
9    * with the License.  You may obtain a copy of the License at
10   *
11   *   http://www.apache.org/licenses/LICENSE-2.0
12   *
13   * Unless required by applicable law or agreed to in writing,
14   * software distributed under the License is distributed on an
15   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16   * KIND, either express or implied.  See the License for the
17   * specific language governing permissions and limitations
18   * under the License.
19   * ====================================================================
20   *
21   * This software consists of voluntary contributions made by many
22   * individuals on behalf of the Apache Software Foundation.  For more
23   * information on the Apache Software Foundation, please see
24   * <http://www.apache.org/>.
25   *
26   */
27  
28  package org.apache.http.impl.conn;
29  
30  import java.io.IOException;
31  
32  import org.apache.commons.logging.Log;
33  import org.apache.commons.logging.LogFactory;
34  import org.apache.http.HttpException;
35  import org.apache.http.HttpResponse;
36  import org.apache.http.HttpResponseFactory;
37  import org.apache.http.NoHttpResponseException;
38  import org.apache.http.ProtocolException;
39  import org.apache.http.StatusLine;
40  import org.apache.http.config.MessageConstraints;
41  import org.apache.http.impl.DefaultHttpResponseFactory;
42  import org.apache.http.impl.io.AbstractMessageParser;
43  import org.apache.http.io.SessionInputBuffer;
44  import org.apache.http.message.LineParser;
45  import org.apache.http.message.ParserCursor;
46  import org.apache.http.params.HttpParams;
47  import org.apache.http.util.Args;
48  import org.apache.http.util.CharArrayBuffer;
49  
50  /**
51   * Lenient HTTP response parser implementation that can skip malformed data until
52   * a valid HTTP response message head is encountered.
53   *
54   * @since 4.2
55   */
56  @SuppressWarnings("deprecation")
57  public class DefaultHttpResponseParser extends AbstractMessageParser<HttpResponse> {
58  
59      private final Log log = LogFactory.getLog(getClass());
60  
61      private final HttpResponseFactory responseFactory;
62      private final CharArrayBuffer lineBuf;
63  
64      /**
65       * @deprecated (4.3) use {@link DefaultHttpResponseParser#DefaultHttpResponseParser(
66       *   SessionInputBuffer, LineParser, HttpResponseFactory, MessageConstraints)}
67       */
68      @Deprecated
69      public DefaultHttpResponseParser(
70              final SessionInputBuffer buffer,
71              final LineParser parser,
72              final HttpResponseFactory responseFactory,
73              final HttpParams params) {
74          super(buffer, parser, params);
75          Args.notNull(responseFactory, "Response factory");
76          this.responseFactory = responseFactory;
77          this.lineBuf = new CharArrayBuffer(128);
78      }
79  
80      /**
81       * Creates new instance of DefaultHttpResponseParser.
82       *
83       * @param buffer the session input buffer.
84       * @param lineParser the line parser. If {@code null}
85       *   {@link org.apache.http.message.BasicLineParser#INSTANCE} will be used.
86       * @param responseFactory HTTP response factory. If {@code null}
87       *   {@link DefaultHttpResponseFactory#INSTANCE} will be used.
88       * @param constraints the message constraints. If {@code null}
89       *   {@link MessageConstraints#DEFAULT} will be used.
90       *
91       * @since 4.3
92       */
93      public DefaultHttpResponseParser(
94              final SessionInputBuffer buffer,
95              final LineParser lineParser,
96              final HttpResponseFactory responseFactory,
97              final MessageConstraints constraints) {
98          super(buffer, lineParser, constraints);
99          this.responseFactory = responseFactory != null ? responseFactory :
100                 DefaultHttpResponseFactory.INSTANCE;
101         this.lineBuf = new CharArrayBuffer(128);
102     }
103 
104     /**
105      * Creates new instance of DefaultHttpResponseParser.
106      *
107      * @param buffer the session input buffer.
108      * @param constraints the message constraints. If {@code null}
109      *   {@link MessageConstraints#DEFAULT} will be used.
110      *
111      * @since 4.3
112      */
113     public DefaultHttpResponseParser(
114         final SessionInputBuffer buffer, final MessageConstraints constraints) {
115         this(buffer, null, null, constraints);
116     }
117 
118     /**
119      * Creates new instance of DefaultHttpResponseParser.
120      *
121      * @param buffer the session input buffer.
122      *
123      * @since 4.3
124      */
125     public DefaultHttpResponseParser(final SessionInputBuffer buffer) {
126         this(buffer, null, null, MessageConstraints.DEFAULT);
127     }
128 
129     @Override
130     protected HttpResponse parseHead(
131             final SessionInputBuffer sessionBuffer) throws IOException, HttpException {
132         //read out the HTTP status string
133         int count = 0;
134         ParserCursor cursor = null;
135         do {
136             // clear the buffer
137             this.lineBuf.clear();
138             final int i = sessionBuffer.readLine(this.lineBuf);
139             if (i == -1 && count == 0) {
140                 // The server just dropped connection on us
141                 throw new NoHttpResponseException("The target server failed to respond");
142             }
143             cursor = new ParserCursor(0, this.lineBuf.length());
144             if (lineParser.hasProtocolVersion(this.lineBuf, cursor)) {
145                 // Got one
146                 break;
147             } else if (i == -1 || reject(this.lineBuf, count)) {
148                 // Giving up
149                 throw new ProtocolException("The server failed to respond with a " +
150                         "valid HTTP response");
151             }
152             if (this.log.isDebugEnabled()) {
153                 this.log.debug("Garbage in response: " + this.lineBuf.toString());
154             }
155             count++;
156         } while(true);
157         //create the status line from the status string
158         final StatusLine statusline = lineParser.parseStatusLine(this.lineBuf, cursor);
159         return this.responseFactory.newHttpResponse(statusline, null);
160     }
161 
162     protected boolean reject(final CharArrayBuffer line, final int count) {
163         return false;
164     }
165 
166 }