source: gs3-extensions/iiif-servlet/trunk/src/gsdl-src/java/org/greenstone/gsdl3/IIIFServerBridge.java@ 32875

Last change on this file since 32875 was 32875, checked in by davidb, 5 years ago

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1/*
2 * IIIFServerBridge.java
3 * Copyright (C) 2018 New Zealand Digital Library, http://www.nzdl.org
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
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., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19package org.greenstone.gsdl3;
20
21import java.io.IOException;
22import java.io.PrintWriter;
23import java.util.HashSet;
24import java.util.Iterator;
25import java.util.Map;
26
27import javax.servlet.ServletConfig;
28import javax.servlet.ServletException;
29import javax.servlet.UnavailableException;
30import javax.servlet.http.HttpServletRequest;
31import javax.servlet.http.HttpServletResponse;
32
33import org.apache.log4j.Logger;
34import org.greenstone.gsdl3.comms.Communicator;
35import org.greenstone.gsdl3.comms.SOAPCommunicator;
36import org.greenstone.gsdl3.core.IIIFMessageRouter;
37import org.greenstone.gsdl3.core.IIIFReceptionist;
38import org.greenstone.gsdl3.util.GSConstants;
39import org.greenstone.gsdl3.util.GSParams;
40import org.greenstone.gsdl3.util.GSXML;
41import org.greenstone.gsdl3.util.IIIFXML;
42import org.greenstone.gsdl3.util.XMLConverter;
43import org.w3c.dom.Document;
44import org.w3c.dom.Element;
45import org.w3c.dom.Node;
46
47/** a class the serve as a bridge between the Cantaloupe IIIF image server and
48 * Greenstone collections. Loosely based on OAIServer
49 *
50 * the init method is called only once - the first time the bridge is established
51 * then doGet() each time a document image request is made
52 * @see Receptionist
53 */
54/**
55 * IIIF server configuration instructions *
56 *
57 */
58public class IIIFServerBridge
59{
60 /** the receptionist to send messages to */
61 protected IIIFReceptionist recept = null;
62
63 /**
64 * The name of the site with which we will finally be dealing, whether it is
65 * a local site or a remote site through a communicator.
66 */
67 protected String site = "";
68
69 static Logger logger = Logger.getLogger(org.greenstone.gsdl3.IIIFServerBridge.class.getName());
70
71 private void configure() throws UnavailableException
72 {
73 // Read in IIIFConfig.xml (residing web/WEB-INF/classes/) and
74 //use it to configure the receptionist.
75 Element iiif_config = IIIFXML.getIIIFConfigXML();
76 if (iiif_config == null)
77 {
78 logger.error("Fail to parse IIIF config file IIIFConfig.xml.");
79 throw new UnavailableException("IIIFServerBridge: Couldn't parse IIIFConfig.xml");
80 }
81 // pass it to the receptionist
82 if (!this.recept.configure(iiif_config)) {
83 logger.error("Couldn't configure IIIF receptionist");
84 throw new UnavailableException("IIIFServerBridge: Couldn't configure receptionist");
85 }
86 }
87
88 /**
89 * initialise the class
90 */
91 public void init(String site_name) throws UnavailableException, Exception
92 {
93 ////GlobalProperties.loadGlobalProperties(config.getServletContext().getRealPath(""));
94
95 org.greenstone.util.GlobalProperties.loadGlobalProperties("");
96 //org.greenstone.util.GlobalProperties.loadGlobalProperties(config.getServletContext().getRealPath(""));
97 //org.greenstone.util.GlobalProperties.loadGlobalProperties("/home/osboxes/research/code/greenstone3-svn/web");
98 java.io.InputStream in = Class.forName("org.greenstone.util.GlobalProperties").getClassLoader().getResourceAsStream("global.properties");
99
100 //String gsdl3_writablehome = System.getProperty("gsdl3.writablehome");
101 String tomcat_context = System.getProperty("tomcat.context");
102 System.err.println("*** in = " + in);
103 //System.err.println("*** gsdl3.writablehome = " + gsdl3_writablehome);
104 System.err.println("*** tomcat.context = " + tomcat_context);
105
106 // the receptionist -the servlet will talk to this
107 this.recept = new IIIFReceptionist();
108
109 //this site_name could consist of comma separated more than one site name.
110 IIIFMessageRouter message_router = new IIIFMessageRouter();
111
112 message_router.setSiteName(site_name);
113 // lots of work is done in this step; see IIIFMessageRouter.java
114 if (!message_router.configure()) {
115 throw new UnavailableException("IIIFServerBridge: Couldn't configure IIIFMessageRouter");
116 }
117 this.recept.setSiteName(site_name);
118 this.recept.setMessageRouter(message_router);
119
120 configure();
121 } // end of init()
122
123 public void remote_init(String remote_site_name, String remote_site_type, String remote_site_address) throws UnavailableException
124 {
125 if (remote_site_name == null || remote_site_type == null || remote_site_address == null)
126 {
127 logger.error("Initialisation paramters not all set!");
128 logger.error("You must have remote_site_name, remote_site_type and remote_site_address set");
129 throw new UnavailableException("IIIFServerBridge: incorrect remote connection parameters specified");
130 }
131
132 // the receptionist -the servlet will talk to this
133 this.recept = new IIIFReceptionist();
134
135 // talking to a remote site, create a communicator
136 Communicator communicator = null;
137 // we need to create the XML to configure the communicator
138 Document site_doc = XMLConverter.newDOM();
139 Element site_elem = site_doc.createElement(GSXML.SITE_ELEM);
140 site_elem.setAttribute(GSXML.TYPE_ATT, remote_site_type);
141 site_elem.setAttribute(GSXML.NAME_ATT, remote_site_name);
142 site_elem.setAttribute(GSXML.ADDRESS_ATT, remote_site_address);
143
144 if (remote_site_type.equals(GSXML.COMM_TYPE_SOAP_JAVA))
145 {
146 communicator = new SOAPCommunicator();
147 }
148 else
149 {
150 logger.error("IIIFServerBridge.init Error: invalid Communicator type: " + remote_site_type);
151 throw new UnavailableException("IIIFServerBridge: invalid communicator type");
152 }
153
154 if (!communicator.configure(site_elem))
155 {
156 logger.error("IIIFServerBridge.init Error: Couldn't configure communicator");
157 throw new UnavailableException("IIIFServerBridge: Couldn't configure communicator");
158 }
159 this.recept.setSiteName(remote_site_name);
160 this.recept.setMessageRouter(communicator);
161
162 configure();
163 } // end of remote_init()
164
165
166 public String doGetDocumentMessage(String identifier)
167 {
168 // oai always requires the content type be text/xml
169 //request.setCharacterEncoding("UTF-8");
170 //response.setContentType("text/xml;charset=UTF-8");
171 //PrintWriter out = response.getWriter();
172 String result = "";
173
174 String[] pairs = new String[2];
175 pairs[0] = "verb=GetRecord";
176 pairs[1] = "identifier="+identifier;
177
178 String verb = "GetRecord";
179 Document response_doc = XMLConverter.newDOM();
180 Element xml_response = IIIFXML.createBasicResponse(response_doc, verb, pairs);
181 Element verb_elem = null;
182
183 // compose the request message to the receptionist
184 Document request_doc = XMLConverter.newDOM();
185 Element xml_message = request_doc.createElement(GSXML.MESSAGE_ELEM);
186 Element xml_request = request_doc.createElement(GSXML.REQUEST_ELEM);
187 // The type attribute is set to be 'oaiService' from OAIServer to OAIReceptionist.
188 ////xml_request.setAttribute(GSXML.TYPE_ATT, OAIXML.OAI_SERVICE); // ****
189 //xml_request.setAttribute(GSXML.LANG_ATT, lang);
190 xml_request.setAttribute(GSXML.TO_ATT, verb);
191 addParams(xml_request, pairs);
192
193 //xml_request.setAttribute(GSXML.OUTPUT_ATT, output);????
194 xml_message.appendChild(xml_request);
195
196 Node xml_result = this.recept.process(xml_message);
197 if (xml_result == null)
198 {
199 logger.info("xml_result is null");
200 verb_elem = IIIFXML.createErrorElement(response_doc, "Internal error", "");
201 xml_response.appendChild(verb_elem);
202 }
203 else
204 {
205
206 //
207 // All response elements are in the form (with a corresponding verb
208 // name): <message> <response> <verb> ... <resumptionToken> .. this
209 // is optional! </resumptionToken> </verb> </response> </message>
210 //
211 Node res = GSXML.getChildByTagName(xml_result, GSXML.RESPONSE_ELEM);
212 if (res == null)
213 {
214 logger.info("response element in xml_result is null");
215 verb_elem = IIIFXML.createErrorElement(response_doc, "Internal error", "");
216 }
217 else {
218 System.err.println("*** res (verb_elem) = " + XMLConverter.getPrettyString(res));
219
220 verb_elem = GSXML.getFirstElementChild(res); // GetRecord
221 Node record_node = GSXML.getFirstElementChild(verb_elem); // record
222 Element metadata_list_elem = (Element)GSXML.getChildByTagName(record_node,"metadata"); // metadata
223
224 System.err.println("*** metadata_list_elem = " + XMLConverter.getPrettyString(metadata_list_elem));
225
226 Element assocfilepath_metadata_elem = (Element)GSXML.getChildByTagName(metadata_list_elem,"assocfilepath");
227 String assocfilepath_metadata_val = GSXML.getNodeText(assocfilepath_metadata_elem);
228
229 Element image_metadata_elem = (Element)GSXML.getChildByTagName(metadata_list_elem,"Image");
230 String image_metadata_val = GSXML.getNodeText(image_metadata_elem);
231
232 result = assocfilepath_metadata_val + "/" + image_metadata_val;
233 }
234
235 // ******
236 xml_response.appendChild(response_doc.importNode(verb_elem, true));
237 /*
238 if ( verb_elem.getTagName().equals(IIIFXML.ERROR))
239 {
240 xml_response.appendChild(response_doc.importNode(verb_elem, true));
241 }
242 else if (IIIFXML.iiif_version.equals(IIIFXML.IIIF_VERSION2)) {
243 xml_response.appendChild(response_doc.importNode(verb_elem, true));
244 }
245 else
246 {
247 GSXML.copyAllChildren(xml_response, verb_elem);
248 }*/
249 }
250 /*
251 out.println("<?xml version='1.0' encoding='UTF-8' ?>");
252 if (this.use_oai_stylesheet)
253 {
254 out.println("<?xml-stylesheet type='text/xsl' href='" + this.oai_stylesheet + "' ?>\n");
255 }
256 out.println(XMLConverter.getPrettyString(xml_response));
257 */
258
259 //return XMLConverter.getPrettyString(xml_response);
260 return result;
261 //return xml_response;
262 }
263
264 /** append parameter elements to the request sent to the receptionist */
265 public void addParams(Element request, String[] pairs)
266 {
267 Document doc = request.getOwnerDocument();
268 // no params apart from the verb
269 if (pairs == null || pairs.length < 2)
270 return;
271
272 /**
273 * the request xml is composed in the form: <request> <param name=.../>
274 * <param name=.../> </request> (No paramList element in between).
275 */
276 for (int i = 1; i < pairs.length; i++)
277 {
278 //the first pair in pairs is the verb=xxx
279 int index = pairs[i].indexOf("=");
280 if (index != -1)
281 { //just a double check
282 Element param = GSXML.createParameter(doc, pairs[i].substring(0, index), IIIFXML.iiifDecode(pairs[i].substring(index + 1)));
283 request.appendChild(param);
284 }
285 }
286 }
287
288
289 public void destroy()
290 {
291 recept.cleanUp();
292 }
293
294}
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