1 package org.codehaus.plexus.util.xml;
2
3 import java.io.File;
4 import java.io.FileNotFoundException;
5 import java.io.FileOutputStream;
6 import java.io.IOException;
7 import java.io.OutputStream;
8 import java.io.OutputStreamWriter;
9 import java.io.StringWriter;
10 import java.io.Writer;
11 import java.util.regex.Matcher;
12 import java.util.regex.Pattern;
13
14 /*
15 * Licensed to the Apache Software Foundation (ASF) under one
16 * or more contributor license agreements. See the NOTICE file
17 * distributed with this work for additional information
18 * regarding copyright ownership. The ASF licenses this file
19 * to you under the Apache License, Version 2.0 (the
20 * "License"); you may not use this file except in compliance
21 * with the License. You may obtain a copy of the License at
22 *
23 * http://www.apache.org/licenses/LICENSE-2.0
24 *
25 * Unless required by applicable law or agreed to in writing,
26 * software distributed under the License is distributed on an
27 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
28 * KIND, either express or implied. See the License for the
29 * specific language governing permissions and limitations
30 * under the License.
31 */
32
33 /**
34 * Character stream that handles (or at least attemtps to) all the necessary Voodo to figure out the charset encoding of
35 * the XML document written to the stream.
36 * @author <a href="mailto:hboutemy@codehaus.org">Herve Boutemy</a>
37 * @version $Id: XmlStreamWriter.java 630430 2008-02-23 13:16:25Z olamy $
38 * @since 1.4.4
39 * @deprecated TO BE REMOVED from here when plexus-utils is upgraded to 1.4.5+ (and prerequisite upgraded to Maven 2.0.6)
40 */
41 public class XmlStreamWriter
42 extends Writer
43 {
44 private static final int BUFFER_SIZE = 4096;
45
46 private StringWriter xmlPrologWriter = new StringWriter( BUFFER_SIZE );
47
48 private OutputStream out;
49
50 private Writer writer;
51
52 private String encoding;
53
54 public XmlStreamWriter( OutputStream out )
55 {
56 this.out = out;
57 }
58
59 public XmlStreamWriter( File file )
60 throws FileNotFoundException
61 {
62 this( new FileOutputStream( file ) );
63 }
64
65 public String getEncoding()
66 {
67 return encoding;
68 }
69
70 public void close()
71 throws IOException
72 {
73 if ( writer == null )
74 {
75 encoding = "UTF-8";
76 writer = new OutputStreamWriter( out, encoding );
77 writer.write( xmlPrologWriter.toString() );
78 }
79 writer.close();
80 }
81
82 public void flush()
83 throws IOException
84 {
85 if ( writer != null )
86 {
87 writer.flush();
88 }
89 }
90
91 private void detectEncoding( char[] cbuf, int off, int len )
92 throws IOException
93 {
94 int size = len;
95 StringBuffer xmlProlog = xmlPrologWriter.getBuffer();
96 if ( xmlProlog.length() + len > BUFFER_SIZE )
97 {
98 size = BUFFER_SIZE - xmlProlog.length();
99 }
100 xmlPrologWriter.write( cbuf, off, size );
101
102 // try to determine encoding
103 if ( xmlProlog.length() >= 5 )
104 {
105 if ( xmlProlog.substring( 0, 5 ).equals( "<?xml" ) )
106 {
107 // try to extract encoding from XML prolog
108 int xmlPrologEnd = xmlProlog.indexOf( "?>" );
109 if ( xmlPrologEnd > 0 )
110 {
111 // ok, full XML prolog written: let's extract encoding
112 Matcher m = ENCODING_PATTERN.matcher( xmlProlog.substring( 0, xmlPrologEnd ) );
113 if ( m.find() )
114 {
115 encoding = m.group( 1 ).toUpperCase();
116 encoding = encoding.substring( 1, encoding.length() - 1 );
117 }
118 else
119 {
120 // no encoding found in XML prolog: using default encoding
121 encoding = "UTF-8";
122 }
123 }
124 else
125 {
126 if ( xmlProlog.length() >= BUFFER_SIZE )
127 {
128 // no encoding found in first characters: using default encoding
129 encoding = "UTF-8";
130 }
131 }
132 }
133 else
134 {
135 // no XML prolog: using default encoding
136 encoding = "UTF-8";
137 }
138 if ( encoding != null )
139 {
140 // encoding has been chosen: let's do it
141 xmlPrologWriter = null;
142 writer = new OutputStreamWriter( out, encoding );
143 writer.write( xmlProlog.toString() );
144 if ( len > size )
145 {
146 writer.write( cbuf, off + size, len - size );
147 }
148 }
149 }
150 }
151
152 public void write( char[] cbuf, int off, int len )
153 throws IOException
154 {
155 if ( xmlPrologWriter != null )
156 {
157 detectEncoding( cbuf, off, len );
158 }
159 else
160 {
161 writer.write( cbuf, off, len );
162 }
163 }
164
165 static final Pattern ENCODING_PATTERN = XmlReader.ENCODING_PATTERN;
166 }