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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.nio.codecs;
29  
30  import java.io.IOException;
31  import java.util.Iterator;
32  
33  import org.apache.http.Header;
34  import org.apache.http.HttpException;
35  import org.apache.http.HttpMessage;
36  import org.apache.http.message.BasicLineFormatter;
37  import org.apache.http.message.LineFormatter;
38  import org.apache.http.nio.NHttpMessageWriter;
39  import org.apache.http.nio.reactor.SessionOutputBuffer;
40  import org.apache.http.params.HttpParams;
41  import org.apache.http.util.Args;
42  import org.apache.http.util.CharArrayBuffer;
43  
44  /**
45   * Abstract {@link NHttpMessageWriter} that serves as a base for all message
46   * writer implementations.
47   *
48   * @since 4.0
49   */
50  @SuppressWarnings("deprecation")
51  public abstract class AbstractMessageWriter<T extends HttpMessage> implements NHttpMessageWriter<T> {
52  
53      protected final SessionOutputBuffer sessionBuffer;
54      protected final CharArrayBuffer lineBuf;
55      protected final LineFormatter lineFormatter;
56  
57      /**
58       * Creates an instance of this class.
59       *
60       * @param buffer the session output buffer.
61       * @param formatter the line formatter.
62       * @param params HTTP parameters.
63       *
64       * @deprecated (4.3) use
65       *   {@link AbstractMessageWriter#AbstractMessageWriter(SessionOutputBuffer, LineFormatter)}
66       */
67      @Deprecated
68      public AbstractMessageWriter(final SessionOutputBuffer buffer,
69                                   final LineFormatter formatter,
70                                   final HttpParams params) {
71          super();
72          Args.notNull(buffer, "Session input buffer");
73          this.sessionBuffer = buffer;
74          this.lineBuf = new CharArrayBuffer(64);
75          this.lineFormatter = (formatter != null) ? formatter : BasicLineFormatter.INSTANCE;
76      }
77  
78      /**
79       * Creates an instance of AbstractMessageWriter.
80       *
81       * @param buffer the session output buffer.
82       * @param formatter the line formatter If {@code null} {@link BasicLineFormatter#INSTANCE}
83       *   will be used.
84       *
85       * @since 4.3
86       */
87      public AbstractMessageWriter(
88              final SessionOutputBuffer buffer,
89              final LineFormatter formatter) {
90          super();
91          this.sessionBuffer = Args.notNull(buffer, "Session input buffer");
92          this.lineFormatter = (formatter != null) ? formatter : BasicLineFormatter.INSTANCE;
93          this.lineBuf = new CharArrayBuffer(64);
94      }
95  
96      @Override
97      public void reset() {
98      }
99  
100     /**
101      * Writes out the first line of {@link HttpMessage}.
102      *
103      * @param message HTTP message.
104      */
105     protected abstract void writeHeadLine(T message) throws IOException;
106 
107     @Override
108     public void write(final T message) throws IOException, HttpException {
109         Args.notNull(message, "HTTP message");
110         writeHeadLine(message);
111         for (final Iterator<?> it = message.headerIterator(); it.hasNext(); ) {
112             final Header header = (Header) it.next();
113             this.sessionBuffer.writeLine
114                 (lineFormatter.formatHeader(this.lineBuf, header));
115         }
116         this.lineBuf.clear();
117         this.sessionBuffer.writeLine(this.lineBuf);
118     }
119 
120 }