1 | /*
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2 | * IIIFServerBridge.java
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3 | * Copyright (C) 2018 New Zealand Digital Library, http://www.nzdl.org
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4 | *
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5 | * This program is free software; you can redistribute it and/or modify
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6 | * it under the terms of the GNU General Public License as published by
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7 | * the Free Software Foundation; either version 2 of the License, or
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8 | * (at your option) any later version.
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9 | *
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10 | * This program is distributed in the hope that it will be useful,
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11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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13 | * GNU General Public License for more details.
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14 | *
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15 | * You should have received a copy of the GNU General Public License
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16 | * along with this program; if not, write to the Free Software
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17 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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18 | */
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19 | package org.greenstone.gsdl3;
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20 |
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21 | import java.io.IOException;
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22 | import java.io.PrintWriter;
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23 | import java.util.HashSet;
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24 | import java.util.Iterator;
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25 | import java.util.Map;
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26 |
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27 | import javax.servlet.ServletConfig;
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28 | import javax.servlet.ServletException;
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29 | import javax.servlet.UnavailableException;
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30 | import javax.servlet.http.HttpServletRequest;
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31 | import javax.servlet.http.HttpServletResponse;
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32 |
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33 | import org.apache.log4j.Logger;
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34 | import org.greenstone.gsdl3.comms.Communicator;
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35 | import org.greenstone.gsdl3.comms.SOAPCommunicator;
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36 | import org.greenstone.gsdl3.core.IIIFMessageRouter;
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37 | import org.greenstone.gsdl3.core.IIIFReceptionist;
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38 | import org.greenstone.gsdl3.util.GSConstants;
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39 | import org.greenstone.gsdl3.util.GSParams;
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40 | import org.greenstone.gsdl3.util.GSXML;
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41 | import org.greenstone.gsdl3.util.IIIFXML;
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42 | import org.greenstone.gsdl3.util.XMLConverter;
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43 | import org.w3c.dom.Document;
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44 | import org.w3c.dom.Element;
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45 | import org.w3c.dom.Node;
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46 |
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47 | /** a class the serve as a bridge between the Cantaloupe IIIF image server and
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48 | * Greenstone collections. Loosely based on OAIServer
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49 | *
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50 | * the init method is called only once - the first time the bridge is established
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51 | * then doGet() each time a document image request is made
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52 | * @see Receptionist
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53 | */
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54 | /**
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55 | * IIIF server configuration instructions *
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56 | *
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57 | */
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58 | public class IIIFServerBridge
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59 | {
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60 | /** the receptionist to send messages to */
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61 | protected IIIFReceptionist recept = null;
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62 |
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63 | /**
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64 | * The name of the site with which we will finally be dealing, whether it is
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65 | * a local site or a remote site through a communicator.
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66 | */
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67 | protected String site = "";
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68 |
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69 | static Logger logger = Logger.getLogger(org.greenstone.gsdl3.IIIFServerBridge.class.getName());
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70 |
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71 | private void configure() throws UnavailableException
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72 | {
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73 | // Read in IIIFConfig.xml (residing web/WEB-INF/classes/) and
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74 | //use it to configure the receptionist.
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75 | Element iiif_config = IIIFXML.getIIIFConfigXML();
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76 | if (iiif_config == null)
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77 | {
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78 | logger.error("Fail to parse IIIF config file IIIFConfig.xml.");
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79 | throw new UnavailableException("IIIFServerBridge: Couldn't parse IIIFConfig.xml");
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80 | }
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81 | // pass it to the receptionist
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82 | if (!this.recept.configure(iiif_config)) {
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83 | logger.error("Couldn't configure IIIF receptionist");
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84 | throw new UnavailableException("IIIFServerBridge: Couldn't configure receptionist");
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85 | }
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86 | }
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87 |
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88 | /**
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89 | * initialise the class
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90 | */
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91 | public void init(String site_name) throws UnavailableException, Exception
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92 | {
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93 | org.greenstone.util.GlobalProperties.loadGlobalProperties("");
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94 | java.io.InputStream in = Class.forName("org.greenstone.util.GlobalProperties").getClassLoader().getResourceAsStream("global.properties");
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95 |
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96 | String tomcat_context = System.getProperty("tomcat.context");
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97 |
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98 | // the receptionist -the servlet will talk to this
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99 | this.recept = new IIIFReceptionist();
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100 |
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101 | //this site_name could consist of comma separated more than one site name.
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102 | IIIFMessageRouter message_router = new IIIFMessageRouter();
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103 |
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104 | message_router.setSiteName(site_name);
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105 | // lots of work is done in this step; see IIIFMessageRouter.java
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106 | if (!message_router.configure()) {
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107 | throw new UnavailableException("IIIFServerBridge: Couldn't configure IIIFMessageRouter");
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108 | }
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109 | this.recept.setSiteName(site_name);
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110 | this.recept.setMessageRouter(message_router);
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111 |
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112 | configure();
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113 | } // end of init()
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114 |
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115 | /*
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116 | Written but never used/tested
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117 | */
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118 |
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119 | public void remote_init(String remote_site_name, String remote_site_type, String remote_site_address) throws UnavailableException
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120 | {
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121 | if (remote_site_name == null || remote_site_type == null || remote_site_address == null)
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122 | {
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123 | logger.error("Initialisation paramters not all set!");
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124 | logger.error("You must have remote_site_name, remote_site_type and remote_site_address set");
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125 | throw new UnavailableException("IIIFServerBridge: incorrect remote connection parameters specified");
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126 | }
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127 |
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128 | // the receptionist -the servlet will talk to this
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129 | this.recept = new IIIFReceptionist();
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130 |
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131 | // talking to a remote site, create a communicator
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132 | Communicator communicator = null;
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133 | // we need to create the XML to configure the communicator
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134 | Document site_doc = XMLConverter.newDOM();
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135 | Element site_elem = site_doc.createElement(GSXML.SITE_ELEM);
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136 | site_elem.setAttribute(GSXML.TYPE_ATT, remote_site_type);
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137 | site_elem.setAttribute(GSXML.NAME_ATT, remote_site_name);
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138 | site_elem.setAttribute(GSXML.ADDRESS_ATT, remote_site_address);
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139 |
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140 | if (remote_site_type.equals(GSXML.COMM_TYPE_SOAP_JAVA))
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141 | {
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142 | communicator = new SOAPCommunicator();
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143 | }
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144 | else
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145 | {
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146 | logger.error("IIIFServerBridge.init Error: invalid Communicator type: " + remote_site_type);
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147 | throw new UnavailableException("IIIFServerBridge: invalid communicator type");
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148 | }
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149 |
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150 | if (!communicator.configure(site_elem))
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151 | {
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152 | logger.error("IIIFServerBridge.init Error: Couldn't configure communicator");
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153 | throw new UnavailableException("IIIFServerBridge: Couldn't configure communicator");
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154 | }
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155 | this.recept.setSiteName(remote_site_name);
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156 | this.recept.setMessageRouter(communicator);
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157 |
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158 | configure();
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159 | } // end of remote_init()
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160 |
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161 |
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162 | public String doGetDocumentMessage(String identifier)
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163 | {
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164 | String result = "";
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165 |
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166 | String[] pairs = new String[2];
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167 | pairs[0] = "verb=GetRecord";
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168 | pairs[1] = "identifier="+identifier;
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169 |
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170 | String verb = "GetRecord";
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171 | Document response_doc = XMLConverter.newDOM();
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172 | //Element xml_response = IIIFXML.createBasicResponse(response_doc, verb, pairs);
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173 | //Element verb_elem = null;
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174 |
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175 | // compose the request message to the receptionist
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176 | Document request_doc = XMLConverter.newDOM();
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177 | Element xml_message = request_doc.createElement(GSXML.MESSAGE_ELEM);
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178 | Element xml_request = request_doc.createElement(GSXML.REQUEST_ELEM);
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179 | xml_request.setAttribute(GSXML.TO_ATT, verb);
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180 | addParams(xml_request, pairs);
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181 |
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182 | xml_message.appendChild(xml_request);
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183 |
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184 | Node xml_result = this.recept.process(xml_message);
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185 | if (xml_result == null)
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186 | {
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187 | logger.error("xml_result is null");
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188 | //verb_elem = IIIFXML.createErrorElement(response_doc, "Internal error", "");
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189 | //xml_response.appendChild(verb_elem);
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190 | }
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191 | else
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192 | {
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193 |
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194 | //
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195 | // All response elements are in the form (with a corresponding verb
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196 | // name): <message> <response> <verb> ... </verb> </response> </message>
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197 | //
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198 | Node res = GSXML.getChildByTagName(xml_result, GSXML.RESPONSE_ELEM);
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199 | if (res == null)
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200 | {
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201 | logger.error("response element in xml_result is null");
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202 | //verb_elem = IIIFXML.createErrorElement(response_doc, "Internal error", "");
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203 | }
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204 | else {
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205 | Element verb_elem = GSXML.getFirstElementChild(res); // GetRecord
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206 | Node record_node = GSXML.getFirstElementChild(verb_elem); // record
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207 | Element metadata_list_elem = (Element)GSXML.getChildByTagName(record_node,"metadata"); // metadata
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208 |
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209 | Element assocfilepath_metadata_elem = (Element)GSXML.getChildByTagName(metadata_list_elem,"assocfilepath");
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210 |
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211 | if (assocfilepath_metadata_elem == null) {
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212 | logger.error("Failed to find metadata 'assocfilepath' for Document " + identifier);
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213 | //verb_elem = IIIFXML.createErrorElement(response_doc, "Internal error", "");
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214 | }
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215 | else {
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216 | String assocfilepath_metadata_val = GSXML.getNodeText(assocfilepath_metadata_elem);
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217 |
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218 | Element image_metadata_elem = (Element)GSXML.getChildByTagName(metadata_list_elem,"Image");
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219 | if (assocfilepath_metadata_elem == null) {
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220 | logger.error("Failed to find metadata 'Image' for Document " + identifier);
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221 | }
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222 | else {
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223 | String image_metadata_val = GSXML.getNodeText(image_metadata_elem);
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224 |
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225 | result = assocfilepath_metadata_val + "/" + image_metadata_val;
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226 | }
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227 | }
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228 | }
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229 |
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230 | //xml_response.appendChild(response_doc.importNode(verb_elem, true));
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231 | }
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232 | return result;
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233 | }
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234 |
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235 | /** append parameter elements to the request sent to the receptionist */
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236 | public void addParams(Element request, String[] pairs)
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237 | {
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238 | Document doc = request.getOwnerDocument();
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239 | // no params apart from the verb
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240 | if (pairs == null || pairs.length < 2)
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241 | return;
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242 |
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243 | /**
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244 | * the request xml is composed in the form: <request> <param name=.../>
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245 | * <param name=.../> </request> (No paramList element in between).
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246 | */
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247 | for (int i = 1; i < pairs.length; i++)
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248 | {
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249 | //the first pair in pairs is the verb=xxx
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250 | int index = pairs[i].indexOf("=");
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251 | if (index != -1)
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252 | { //just a double check
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253 | Element param = GSXML.createParameter(doc, pairs[i].substring(0, index), IIIFXML.iiifDecode(pairs[i].substring(index + 1)));
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254 | request.appendChild(param);
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255 | }
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256 | }
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257 | }
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258 |
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259 |
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260 | public void destroy()
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261 | {
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262 | recept.cleanUp();
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263 | }
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264 |
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265 | }
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