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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *  
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *  
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  package org.apache.mina.http;
21  
22  import java.nio.ByteBuffer;
23  import java.util.HashMap;
24  import java.util.Map;
25  import java.util.regex.Pattern;
26  
27  import org.apache.mina.core.buffer.IoBuffer;
28  import org.apache.mina.core.session.IoSession;
29  import org.apache.mina.filter.codec.ProtocolDecoder;
30  import org.apache.mina.filter.codec.ProtocolDecoderOutput;
31  import org.apache.mina.http.api.DefaultHttpResponse;
32  import org.apache.mina.http.api.HttpEndOfContent;
33  import org.apache.mina.http.api.HttpStatus;
34  import org.apache.mina.http.api.HttpVersion;
35  import org.slf4j.Logger;
36  import org.slf4j.LoggerFactory;
37  
38  public class HttpClientDecoder implements ProtocolDecoder {
39      private static final Logger LOG = LoggerFactory.getLogger(HttpClientCodec.class);
40  
41      /** Key for decoder current state */
42      private static final String DECODER_STATE_ATT = "http.ds";
43  
44      /** Key for the partial HTTP requests head */
45      private static final String PARTIAL_HEAD_ATT = "http.ph";
46  
47      /** Key for the number of bytes remaining to read for completing the body */
48      private static final String BODY_REMAINING_BYTES = "http.brb";
49      
50      /** Key for indicating chunked data */
51      private static final String BODY_CHUNKED = "http.ckd";
52      
53      /** Regex to parse HttpRequest Request Line */
54      public static final Pattern REQUEST_LINE_PATTERN = Pattern.compile(" ");
55  
56      /** Regex to parse HttpRequest Request Line */
57      public static final Pattern RESPONSE_LINE_PATTERN = Pattern.compile(" ");
58  
59      /** Regex to parse out QueryString from HttpRequest */
60      public static final Pattern QUERY_STRING_PATTERN = Pattern.compile("\\?");
61  
62      /** Regex to parse out parameters from query string */
63      public static final Pattern PARAM_STRING_PATTERN = Pattern.compile("\\&|;");
64  
65      /** Regex to parse out key/value pairs */
66      public static final Pattern KEY_VALUE_PATTERN = Pattern.compile("=");
67  
68      /** Regex to parse raw headers and body */
69      public static final Pattern RAW_VALUE_PATTERN = Pattern.compile("\\r\\n\\r\\n");
70  
71      /** Regex to parse raw headers from body */
72      public static final Pattern HEADERS_BODY_PATTERN = Pattern.compile("\\r\\n");
73  
74      /** Regex to parse header name and value */
75      public static final Pattern HEADER_VALUE_PATTERN = Pattern.compile(": ");
76  
77      /** Regex to split cookie header following RFC6265 Section 5.4 */
78      public static final Pattern COOKIE_SEPARATOR_PATTERN = Pattern.compile(";");
79  
80      public void decode(final IoSession session, final IoBuffer msg, final ProtocolDecoderOutput out) {
81          DecoderState state = (DecoderState)session.getAttribute(DECODER_STATE_ATT);
82          if (null == state) {
83              session.setAttribute(DECODER_STATE_ATT, DecoderState.NEW);
84              state = (DecoderState)session.getAttribute(DECODER_STATE_ATT);
85          }
86          switch (state) {
87          case HEAD:
88              LOG.debug("decoding HEAD");
89              // grab the stored a partial HEAD request
90              final ByteBuffer oldBuffer = (ByteBuffer)session.getAttribute(PARTIAL_HEAD_ATT);
91              // concat the old buffer and the new incoming one
92              IoBuffer.allocate(oldBuffer.remaining() + msg.remaining()).put(oldBuffer).put(msg).flip();
93              // now let's decode like it was a new message
94  
95          case NEW:
96              LOG.debug("decoding NEW");
97              final DefaultHttpResponse rp = parseHttpReponseHead(msg.buf());
98  
99              if (rp == null) {
100                 // we copy the incoming BB because it's going to be recycled by the inner IoProcessor for next reads
101                 final ByteBuffer partial = ByteBuffer.allocate(msg.remaining());
102                 partial.put(msg.buf());
103                 partial.flip();
104                 // no request decoded, we accumulate
105                 session.setAttribute(PARTIAL_HEAD_ATT, partial);
106                 session.setAttribute(DECODER_STATE_ATT, DecoderState.HEAD);
107             } else {
108                 out.write(rp);
109                 // is it a response with some body content ?
110                 LOG.debug("response with content");
111                 session.setAttribute(DECODER_STATE_ATT, DecoderState.BODY);
112 
113                 final String contentLen = rp.getHeader("content-length");
114 
115                 if (contentLen != null) {
116                     LOG.debug("found content len : {}", contentLen);
117                     session.setAttribute(BODY_REMAINING_BYTES, Integer.valueOf(contentLen));
118                 } else if ("chunked".equalsIgnoreCase(rp.getHeader("transfer-encoding"))) {
119                     LOG.debug("no content len but chunked");
120                     session.setAttribute(BODY_CHUNKED, Boolean.valueOf("true"));
121                 } else if ("close".equalsIgnoreCase(rp.getHeader("connection"))) {
122                     session.close(true);
123                 } else {
124                     throw new HttpException(HttpStatus.CLIENT_ERROR_LENGTH_REQUIRED, "no content length !");
125                 }
126             }
127 
128             break;
129 
130         case BODY:
131             LOG.debug("decoding BODY: {} bytes", msg.remaining());
132             final int chunkSize = msg.remaining();
133             // send the chunk of body
134             if (chunkSize != 0) {
135                 final IoBuffer wb = IoBuffer.allocate(msg.remaining());
136                 wb.put(msg);
137                 wb.flip();
138                 out.write(wb);
139             }
140             msg.position(msg.limit());
141             
142             // do we have reach end of body ?
143             int remaining = 0;
144             
145             // if chunked, remaining is the msg.remaining()
146             if( session.getAttribute(BODY_CHUNKED) != null ) {
147                 remaining = chunkSize;
148             } else {
149                 // otherwise, manage with content-length
150                 remaining = (Integer) session.getAttribute(BODY_REMAINING_BYTES);
151                 remaining -= chunkSize;
152             }
153 
154             if (remaining <= 0 ) {
155                 LOG.debug("end of HTTP body");
156                 session.setAttribute(DECODER_STATE_ATT, DecoderState.NEW);
157                 session.removeAttribute(BODY_REMAINING_BYTES);
158                 if( session.getAttribute(BODY_CHUNKED) != null ) {
159                     session.removeAttribute(BODY_CHUNKED);
160                 }
161                 out.write(new HttpEndOfContent());
162             } else {
163                 if( session.getAttribute(BODY_CHUNKED) == null ) {
164                     session.setAttribute(BODY_REMAINING_BYTES, Integer.valueOf(remaining));
165                 }
166             }
167 
168             break;
169 
170         default:
171             throw new HttpException(HttpStatus.SERVER_ERROR_INTERNAL_SERVER_ERROR, "Unknonwn decoder state : " + state);
172         }
173     }
174 
175     public void finishDecode(final IoSession session, final ProtocolDecoderOutput out) throws Exception {
176     }
177 
178     public void dispose(final IoSession session) throws Exception {
179     }
180 
181     private DefaultHttpResponse parseHttpReponseHead(final ByteBuffer buffer) {
182         // Java 6 >> String raw = new String(buffer.array(), 0, buffer.limit(), Charset.forName("UTF-8"));
183         final String raw = new String(buffer.array(), 0, buffer.limit());
184         final String[] headersAndBody = RAW_VALUE_PATTERN.split(raw, -1);
185         if (headersAndBody.length <= 1) {
186             // we didn't receive the full HTTP head
187             return null;
188         }
189 
190         String[] headerFields = HEADERS_BODY_PATTERN.split(headersAndBody[0]);
191         headerFields = ArrayUtil.dropFromEndWhile(headerFields, "");
192 
193         final String requestLine = headerFields[0];
194         final Map<String, String> generalHeaders = new HashMap<String, String>();
195 
196         for (int i = 1; i < headerFields.length; i++) {
197             final String[] header = HEADER_VALUE_PATTERN.split(headerFields[i]);
198             generalHeaders.put(header[0].toLowerCase(), header[1]);
199         }
200 
201         final String[] elements = RESPONSE_LINE_PATTERN.split(requestLine);
202         HttpStatus status = null;
203         final int statusCode = Integer.valueOf(elements[1]);
204         for (int i = 0; i < HttpStatus.values().length; i++) {
205             status = HttpStatus.values()[i];
206             if (statusCode == status.code()) {
207                 break;
208             }
209         }
210         final HttpVersion version = HttpVersion.fromString(elements[0]);
211 
212         // we put the buffer position where we found the beginning of the HTTP body
213         buffer.position(headersAndBody[0].length() + 4);
214 
215         return new DefaultHttpResponse(version, status, generalHeaders);
216     }
217 }