1 /*
2 * $Header: /home/cvs/jakarta-commons-sandbox/jelly/src/java/org/apache/commons/jelly/tags/xml/ParseTag.java,v 1.9 2002/06/26 09:24:35 jstrachan Exp $
3 * $Revision: 1.9 $
4 * $Date: 2002/06/26 09:24:35 $
5 *
6 * ====================================================================
7 *
8 * The Apache Software License, Version 1.1
9 *
10 * Copyright (c) 1999-2002 The Apache Software Foundation. All rights
11 * reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 *
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 *
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in
22 * the documentation and/or other materials provided with the
23 * distribution.
24 *
25 * 3. The end-user documentation included with the redistribution, if
26 * any, must include the following acknowlegement:
27 * "This product includes software developed by the
28 * Apache Software Foundation (http://www.apache.org/)."
29 * Alternately, this acknowlegement may appear in the software itself,
30 * if and wherever such third-party acknowlegements normally appear.
31 *
32 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
33 * Foundation" must not be used to endorse or promote products derived
34 * from this software without prior written permission. For written
35 * permission, please contact apache@apache.org.
36 *
37 * 5. Products derived from this software may not be called "Apache"
38 * nor may "Apache" appear in their names without prior written
39 * permission of the Apache Group.
40 *
41 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
42 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
43 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
44 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
45 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
46 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
47 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
48 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
49 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
50 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
51 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 * ====================================================================
54 *
55 * This software consists of voluntary contributions made by many
56 * individuals on behalf of the Apache Software Foundation. For more
57 * information on the Apache Software Foundation, please see
58 * <http://www.apache.org/>.
59 *
60 * $Id: ParseTag.java,v 1.9 2002/06/26 09:24:35 jstrachan Exp $
61 */
62 package org.apache.commons.jelly.tags.xml;
63
64 import java.io.InputStream;
65 import java.io.Reader;
66 import java.io.StringReader;
67 import java.io.StringWriter;
68 import java.io.Writer;
69 import java.net.MalformedURLException;
70 import java.net.URL;
71
72 import org.apache.commons.jelly.TagSupport;
73 import org.apache.commons.jelly.XMLOutput;
74
75 import org.apache.commons.logging.Log;
76 import org.apache.commons.logging.LogFactory;
77
78 import org.dom4j.Document;
79 import org.dom4j.io.SAXContentHandler;
80 import org.dom4j.io.SAXReader;
81
82 /***
83 * An abstract base class for any tag which parsers its body as XML.
84 *
85 * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
86 * @version $Revision: 1.9 $
87 */
88 public abstract class ParseTagSupport extends TagSupport {
89
90 /*** The Log to which logging calls will be made. */
91 private static final Log log = LogFactory.getLog(ParseTagSupport.class);
92
93 /*** The variable that will be generated for the document */
94 private String var;
95
96 /*** The SAXReader used to parser the document */
97 private SAXReader saxReader;
98
99 public ParseTagSupport() {
100 }
101
102
103 // Properties
104 //-------------------------------------------------------------------------
105 /*** The variable name that will be used for the Document variable created
106 */
107 public String getVar() {
108 return var;
109 }
110
111 /*** Sets the variable name that will be used for the Document variable created
112 */
113 public void setVar(String var) {
114 this.var = var;
115 }
116
117 /*** @return the SAXReader used for parsing, creating one lazily if need be */
118 public SAXReader getSAXReader() throws Exception {
119 if (saxReader == null) {
120 saxReader = createSAXReader();
121 }
122 return saxReader;
123 }
124
125 /*** Sets the SAXReader used for parsing */
126 public void setSAXReader(SAXReader saxReader) {
127 this.saxReader = saxReader;
128 }
129
130
131 // Implementation methods
132 //-------------------------------------------------------------------------
133
134 /***
135 * Factory method to create a new SAXReader
136 */
137 protected abstract SAXReader createSAXReader() throws Exception;
138
139
140 /***
141 * Parses the body of this tag and returns the parsed document
142 */
143 protected Document parseBody(XMLOutput output) throws Exception {
144 SAXContentHandler handler = new SAXContentHandler();
145 XMLOutput newOutput = new XMLOutput(handler);
146 handler.startDocument();
147 invokeBody( newOutput);
148 handler.endDocument();
149 return handler.getDocument();
150
151 /*
152 // the following is inefficient as it requires a parse of the text
153 // but is left here in the code to see how it could be done.
154
155 String text = getBodyText();
156
157 if ( log.isDebugEnabled() ) {
158 log.debug( "About to parse: " + text );
159 }
160 return getSAXReader().read( new StringReader( text ) );
161 */
162 }
163
164 /***
165 * Parses the given source
166 */
167 protected Document parse(Object source) throws Exception {
168 // #### we should allow parsing to output XML events to
169 // the output if no var is specified
170
171 if (source instanceof String) {
172 String uri = (String) source;
173 InputStream in = context.getResourceAsStream(uri);
174 return getSAXReader().read(in, uri);
175 }
176 else if (source instanceof Reader) {
177 return getSAXReader().read((Reader) source);
178 }
179 else if (source instanceof InputStream) {
180 return getSAXReader().read((InputStream) source);
181 }
182 else if (source instanceof URL) {
183 return getSAXReader().read((URL) source);
184 }
185 else {
186 throw new IllegalArgumentException(
187 "Invalid source argument. Must be a String, Reader, InputStream or URL."
188 + " Was type; "
189 + source.getClass().getName()
190 + " with value: "
191 + source);
192 }
193 }
194 }
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