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comparison common/src/main/java/digilib/meta/XMLMetaLoader.java @ 903:7779b37d1d05

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refactored into maven modules per servlet type. can build servlet-api 2.3 and 3.0 via profile now!
author robcast
date Tue, 26 Apr 2011 20:24:31 +0200
parents servlet/src/main/java/digilib/meta/XMLMetaLoader.java@ba1eb2d821a2
children
comparison
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902:89ba3ffcf552 903:7779b37d1d05
1 /* XMLMetaLoader -- Load an XML format metadata into a Hashtable
2
3 Digital Image Library servlet components
4
5 Copyright (C) 2003 Robert Casties (robcast@mail.berlios.de)
6
7 This program is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 2 of the License, or (at your
10 option) any later version.
11
12 Please read license.txt for the full details. A copy of the GPL
13 may be found at http://www.gnu.org/copyleft/lgpl.html
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19 */
20
21 package digilib.meta;
22
23 import java.io.IOException;
24 import java.util.HashMap;
25 import java.util.LinkedList;
26 import java.util.Map;
27
28 import javax.xml.parsers.ParserConfigurationException;
29 import javax.xml.parsers.SAXParser;
30 import javax.xml.parsers.SAXParserFactory;
31
32 import org.apache.log4j.Logger;
33 import org.xml.sax.Attributes;
34 import org.xml.sax.SAXException;
35 import org.xml.sax.helpers.DefaultHandler;
36
37 public class XMLMetaLoader {
38
39 private Logger logger = Logger.getLogger(this.getClass());
40 private String metaTag = "meta";
41 private String fileTag = "file";
42 private String fileNameTag = "name";
43 private String filePathTag = "path";
44 private String imgTag = "img";
45 private String collectTag = "context";
46
47 public XMLMetaLoader() {
48 }
49
50 /**
51 * inner class XMLMetaParser to be called by the parser
52 */
53 private class XMLMetaParser extends DefaultHandler {
54
55 private LinkedList<String> tags;
56 private Map<String, MetadataMap> files;
57 private MetadataMap meta;
58 private StringBuffer content;
59 private boolean collecting;
60 private StringBuffer collectedContent;
61 private String fileName;
62 private String filePath;
63
64 /**
65 * extracts the elements name from either localName ln or qName qn.
66 *
67 * @param ln localName
68 * @param qn qName
69 * @return element name
70 */
71 private String getName(String ln, String qn) {
72 if (ln != null) {
73 if (ln.length() > 0) {
74 return ln;
75 }
76 }
77 // else it's qName (or nothing)
78 return qn;
79 }
80
81 /**
82 * returns all attributes as a String
83 *
84 * @param attrs
85 * @return
86 */
87 private String getAttrString(Attributes attrs) {
88 StringBuffer s = new StringBuffer();
89 for (int i = 0; i < attrs.getLength(); i++) {
90 String key = getName(attrs.getLocalName(i), attrs.getQName(i));
91 s.append(" "+key+"=\""+attrs.getValue(i)+"\"");
92 }
93 return s.toString();
94 }
95
96
97 // Parser calls this once at the beginning of a document
98 public void startDocument() throws SAXException {
99 tags = new LinkedList<String>();
100 files = new HashMap<String, MetadataMap>();
101 collecting = false;
102 collectedContent = null;
103 }
104
105 // Parser calls this for each element in a document
106 public void startElement(
107 String namespaceURI,
108 String localName,
109 String qName,
110 Attributes atts)
111 throws SAXException {
112
113 String name = getName(localName, qName);
114 // open a new tag
115 tags.addLast(name);
116 // start new content (no nesting of tags and content)
117 content = new StringBuffer();
118
119 if (name.equals(metaTag)) {
120 // new meta tag
121 meta = new MetadataMap();
122 collectedContent = new StringBuffer();
123 } else if (name.equals(fileTag)) {
124 // new file tag
125 fileName = null;
126 filePath = null;
127 meta = new MetadataMap();
128 collectedContent = new StringBuffer();
129 } else if (name.equals(collectTag)) {
130 // start collecting
131 collecting = true;
132 if (collectedContent == null) {
133 collectedContent = new StringBuffer();
134 }
135 }
136
137 // record mode
138 if (collecting) {
139 collectedContent.append("<"+name);
140 collectedContent.append(getAttrString(atts));
141 collectedContent.append(">");
142 }
143 }
144
145 // parser calls this for all tag content (possibly more than once)
146 public void characters(char[] ch, int start, int length)
147 throws SAXException {
148 // append data to current string buffer
149 if (content == null) {
150 content = new StringBuffer();
151 }
152 content.append(ch, start, length);
153 }
154
155 // parser calls this at the end of each element
156 public void endElement(
157 String namespaceURI,
158 String localName,
159 String qName)
160 throws SAXException {
161
162 String name = getName(localName, qName);
163 // exit the tag
164 tags.removeLast();
165 String lastTag = (tags.isEmpty()) ? "" : tags.getLast();
166
167 // was it a file/name tag?
168 if (name.equals(fileNameTag) && lastTag.equals(fileTag)) {
169 // save name as filename
170 if ((content != null) && (content.length() > 0)) {
171 fileName = content.toString().trim();
172 }
173 content = null;
174 return;
175 }
176
177 // was it a file/path tag?
178 if (name.equals(filePathTag) && lastTag.equals(fileTag)) {
179 // save path as filepath
180 if ((content != null) && (content.length() > 0)) {
181 filePath = content.toString().trim();
182 }
183 content = null;
184 return;
185 }
186
187 // was it a file tag?
188 if (name.equals(fileTag)) {
189 // is there meta to save?
190 if ((meta != null) && (meta.size() > 0)) {
191 // file name is (optional file/path) / file/name
192 String fn = null;
193
194 if (fileName != null) {
195 if (filePath != null) {
196 fn = filePath + "/" + fileName;
197 } else {
198 fn = fileName;
199 }
200 } else {
201 // no file name, no file
202 content = null;
203 return;
204 }
205 // save meta in file list
206 files.put(fn, meta);
207 }
208 content = null;
209 return;
210 }
211
212 // was it a meta tag outside a file tag?
213 if (name.equals(metaTag) && !tags.contains(fileTag)) {
214 // save meta as dir meta
215 if ((meta != null) && (meta.size() > 0)) {
216 files.put("", meta);
217 }
218 content = null;
219 return;
220 }
221
222 // is this inside an digilib info (=img) tag?
223 if (lastTag.equals(imgTag)) {
224 // then add whatever this is
225 if ((content != null) && (content.length() > 0)) {
226 meta.put(name, content.toString().trim());
227 }
228 content = null;
229 return;
230 }
231
232 // is this the end of collectTag?
233 if (name.equals(collectTag)) {
234 collecting = false;
235 collectedContent.append("</"+collectTag+">\n");
236 // store collected stuff
237 meta.put(collectTag, collectedContent.toString());
238 //logger.debug("collected: '"+collectedContent+"'");
239 content = null;
240 return;
241 }
242
243 // write collected content
244 if (collecting) {
245 String s = "";
246 if ((content != null) && (content.length() > 0)) {
247 s = content.toString().trim();
248 }
249 //logger.debug("collect:"+name+" = "+s);
250 collectedContent.append(s);
251 collectedContent.append("</"+name+">\n");
252 content = null;
253 return;
254 }
255 }
256
257 }
258
259 /**
260 * load and parse a file (as URL)
261 * returns HashMap with list data
262 */
263 public Map<String, MetadataMap> loadURL(String path) throws SAXException, IOException {
264 logger.debug("loading meta: "+path);
265 // Create a JAXP SAXParserFactory and configure it
266 SAXParserFactory spf = SAXParserFactory.newInstance();
267 spf.setNamespaceAware(true);
268
269 SAXParser parser = null;
270 try {
271 // Create a JAXP SAXParser
272 parser = spf.newSAXParser();
273
274 } catch (ParserConfigurationException e) {
275 throw new SAXException(e);
276 }
277
278 // create a list parser (keeps the data!)
279 XMLMetaParser listParser = new XMLMetaParser();
280
281 // Tell the SAXParser to parse the XML document
282 parser.parse(path, listParser);
283
284 return listParser.files;
285 }
286
287 }