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.io;
29
30 import java.io.IOException;
31
32 import org.apache.http.Header;
33 import org.apache.http.HeaderIterator;
34 import org.apache.http.HttpException;
35 import org.apache.http.HttpMessage;
36 import org.apache.http.annotation.NotThreadSafe;
37 import org.apache.http.io.HttpMessageWriter;
38 import org.apache.http.io.SessionOutputBuffer;
39 import org.apache.http.message.LineFormatter;
40 import org.apache.http.message.BasicLineFormatter;
41 import org.apache.http.params.HttpParams;
42 import org.apache.http.util.CharArrayBuffer;
43
44 /**
45 * Abstract base class for HTTP message writers that serialize output to
46 * an instance of {@link SessionOutputBuffer}.
47 *
48 * @since 4.0
49 */
50 @NotThreadSafe
51 public abstract class AbstractMessageWriter<T extends HttpMessage> implements HttpMessageWriter<T> {
52
53 protected final SessionOutputBuffer sessionBuffer;
54 protected final CharArrayBuffer lineBuf;
55 protected final LineFormatter lineFormatter;
56
57 /**
58 * Creates an instance of AbstractMessageWriter.
59 *
60 * @param buffer the session output buffer.
61 * @param formatter the line formatter.
62 * @param params HTTP parameters.
63 */
64 public AbstractMessageWriter(final SessionOutputBuffer buffer,
65 final LineFormatter formatter,
66 final HttpParams params) {
67 super();
68 if (buffer == null) {
69 throw new IllegalArgumentException("Session input buffer may not be null");
70 }
71 this.sessionBuffer = buffer;
72 this.lineBuf = new CharArrayBuffer(128);
73 this.lineFormatter = (formatter != null) ?
74 formatter : BasicLineFormatter.DEFAULT;
75 }
76
77 /**
78 * Subclasses must override this method to write out the first header line
79 * based on the {@link HttpMessage} passed as a parameter.
80 *
81 * @param message the message whose first line is to be written out.
82 * @throws IOException in case of an I/O error.
83 */
84 protected abstract void writeHeadLine(T message) throws IOException;
85
86 public void write(final T message) throws IOException, HttpException {
87 if (message == null) {
88 throw new IllegalArgumentException("HTTP message may not be null");
89 }
90 writeHeadLine(message);
91 for (HeaderIterator it = message.headerIterator(); it.hasNext(); ) {
92 Header header = it.nextHeader();
93 this.sessionBuffer.writeLine
94 (lineFormatter.formatHeader(this.lineBuf, header));
95 }
96 this.lineBuf.clear();
97 this.sessionBuffer.writeLine(this.lineBuf);
98 }
99
100 }