001: /*
002: * $HeadURL: https://svn.apache.org/repos/asf/httpcomponents/httpcore/tags/4.0-beta1/module-main/src/main/java/org/apache/http/message/LineFormatter.java $
003: * $Revision: 573864 $
004: * $Date: 2007-09-08 17:53:25 +0200 (Sat, 08 Sep 2007) $
005: *
006: * ====================================================================
007: * Licensed to the Apache Software Foundation (ASF) under one
008: * or more contributor license agreements. See the NOTICE file
009: * distributed with this work for additional information
010: * regarding copyright ownership. The ASF licenses this file
011: * to you under the Apache License, Version 2.0 (the
012: * "License"); you may not use this file except in compliance
013: * with the License. You may obtain a copy of the License at
014: *
015: * http://www.apache.org/licenses/LICENSE-2.0
016: *
017: * Unless required by applicable law or agreed to in writing,
018: * software distributed under the License is distributed on an
019: * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
020: * KIND, either express or implied. See the License for the
021: * specific language governing permissions and limitations
022: * under the License.
023: * ====================================================================
024: *
025: * This software consists of voluntary contributions made by many
026: * individuals on behalf of the Apache Software Foundation. For more
027: * information on the Apache Software Foundation, please see
028: * <http://www.apache.org/>.
029: *
030: */
031:
032: package org.apache.http.message;
033:
034: import org.apache.http.ProtocolVersion;
035: import org.apache.http.RequestLine;
036: import org.apache.http.StatusLine;
037: import org.apache.http.Header;
038: import org.apache.http.util.CharArrayBuffer;
039:
040: /**
041: * Interface for formatting elements of the HEAD section of an HTTP message.
042: * This is the complement to {@link LineParser}.
043: * There are individual methods for formatting a request line, a
044: * status line, or a header line. The formatting does <i>not</i> include the
045: * trailing line break sequence CR-LF.
046: * Instances of this interface are expected to be stateless and thread-safe.
047: *
048: * <p>
049: * The formatted lines are returned in memory, the formatter does not depend
050: * on any specific IO mechanism.
051: * In order to avoid unnecessary creation of temporary objects,
052: * a buffer can be passed as argument to all formatting methods.
053: * The implementation may or may not actually use that buffer for formatting.
054: * If it is used, the buffer will first be cleared by the
055: * <code>formatXXX</code> methods.
056: * The argument buffer can always be re-used after the call. The buffer
057: * returned as the result, if it is different from the argument buffer,
058: * MUST NOT be modified.
059: * </p>
060: *
061: *
062: * @author <a href="mailto:rolandw AT apache.org">Roland Weber</a>
063: *
064: *
065: * <!-- empty lines above to avoid 'svn diff' context problems -->
066: * @version $Revision: 573864 $ $Date: 2007-09-08 17:53:25 +0200 (Sat, 08 Sep 2007) $
067: *
068: * @since 4.0
069: */
070: public interface LineFormatter {
071:
072: /**
073: * Formats a protocol version.
074: * This method does <i>not</i> follow the general contract for
075: * <code>buffer</code> arguments.
076: * It does <i>not</i> clear the argument buffer, but appends instead.
077: * The returned buffer can always be modified by the caller.
078: * Because of these differing conventions, it is not named
079: * <code>formatProtocolVersion</code>.
080: *
081: * @param buffer a buffer to which to append, or <code>null</code>
082: * @param version the protocol version to format
083: *
084: * @return a buffer with the formatted protocol version appended.
085: * The caller is allowed to modify the result buffer.
086: * If the <code>buffer</code> argument is not <code>null</code>,
087: * the returned buffer is the argument buffer.
088: */
089: CharArrayBuffer appendProtocolVersion(CharArrayBuffer buffer,
090: ProtocolVersion version);
091:
092: /**
093: * Formats a request line.
094: *
095: * @param buffer a buffer available for formatting, or
096: * <code>null</code>.
097: * The buffer will be cleared before use.
098: * @param reqline the request line to format
099: *
100: * @return the formatted request line
101: */
102: CharArrayBuffer formatRequestLine(CharArrayBuffer buffer,
103: RequestLine reqline);
104:
105: /**
106: * Formats a status line.
107: *
108: * @param buffer a buffer available for formatting, or
109: * <code>null</code>.
110: * The buffer will be cleared before use.
111: * @param statline the status line to format
112: *
113: * @return the formatted status line
114: *
115: * @throws ParseException in case of a parse error
116: */
117: CharArrayBuffer formatStatusLine(CharArrayBuffer buffer,
118: StatusLine statline);
119:
120: /**
121: * Formats a header.
122: * Due to header continuation, the result may be multiple lines.
123: * In order to generate well-formed HTTP, the lines in the result
124: * must be separated by the HTTP line break sequence CR-LF.
125: * There is <i>no</i> trailing CR-LF in the result.
126: * <br/>
127: * See the class comment for details about the buffer argument.
128: *
129: * @param buffer a buffer available for formatting, or
130: * <code>null</code>.
131: * The buffer will be cleared before use.
132: * @param header the header to format
133: *
134: * @return a buffer holding the formatted header, never <code>null</code>.
135: * The returned buffer may be different from the argument buffer.
136: *
137: * @throws ParseException in case of a parse error
138: */
139: CharArrayBuffer formatHeader(CharArrayBuffer buffer, Header header);
140:
141: }
|