1 | /*
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2 | * ServiceRack.java
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3 | * Copyright (C) 2002 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.service;
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20 |
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21 | // greenstone classes
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22 | import java.lang.reflect.Method;
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23 | import java.util.HashMap;
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24 |
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25 | import org.apache.log4j.Logger;
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26 | import org.greenstone.gsdl3.core.MessageRouter;
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27 | import org.greenstone.gsdl3.core.ModuleInterface;
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28 | import org.greenstone.gsdl3.util.CollectionClassLoader;
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29 | import org.greenstone.gsdl3.util.Dictionary;
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30 | import org.greenstone.gsdl3.util.GSPath;
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31 | import org.greenstone.gsdl3.util.GSXML;
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32 | import org.greenstone.gsdl3.util.XMLConverter;
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33 | import org.w3c.dom.Document;
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34 | import org.w3c.dom.Element;
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35 | import org.w3c.dom.Node;
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36 | import org.w3c.dom.NodeList;
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37 |
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38 | /**
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39 | * ServiceRack - abstract base class for services
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40 | *
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41 | * A ServiceRack provides one or more Services. This base class implements the
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42 | * process method. Each service is invoked by a method called process<service
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43 | * name> which takes one parameter - the xml request Element, and returns an XML
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44 | * response Element. for example, the TextQuery service would be invoked by
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45 | * processTextQuery(Element request)
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46 | *
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47 | * @author Katherine Don
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48 | */
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49 | public abstract class ServiceRack implements ModuleInterface
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50 | {
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51 |
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52 | static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.ServiceRack.class.getName());
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53 |
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54 | /** the absolute address of the site home */
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55 | protected String site_home = null;
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56 | /** the http address of the site home */
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57 | protected String site_http_address = null;
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58 |
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59 | protected String library_name = null;
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60 | /**
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61 | * the name of the cluster (or collection) that this service belongs to - if
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62 | * any
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63 | */
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64 | protected String cluster_name = null;
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65 |
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66 | /** some services can talk back to the message router */
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67 | protected MessageRouter router = null;
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68 |
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69 | /** a converter class to create Documents etc */
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70 | protected XMLConverter converter = null;
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71 |
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72 | /** the original config info - if need to store it */
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73 | protected Element config_info = null;
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74 |
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75 | /** XML element for describe requests - the container doc */
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76 | protected Document doc = null;
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77 |
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78 | /**
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79 | * XML element for describe requests - list of supported services - this is
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80 | * static
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81 | */
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82 | protected Element short_service_info = null;
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83 |
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84 | /**
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85 | * XML element for stylesheet requests - map of service name to format elem
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86 | */
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87 | protected HashMap<String, Node> format_info_map = null;
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88 |
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89 | protected Element _globalFormat = null;
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90 |
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91 | /**
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92 | * A class loader that knows about the collection resources directory can
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93 | * put properties files, dtds etc in here
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94 | */
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95 | CollectionClassLoader class_loader = null;
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96 |
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97 | /** sets the cluster name */
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98 | public void setClusterName(String cluster_name)
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99 | {
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100 | this.cluster_name = cluster_name;
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101 | }
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102 |
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103 | /** sets the collect name */
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104 | public void setCollectionName(String coll_name)
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105 | {
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106 | setClusterName(coll_name);
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107 | }
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108 |
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109 | public void cleanUp()
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110 | {
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111 | }
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112 |
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113 | public void setGlobalFormat(Element globalFormat)
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114 | {
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115 | _globalFormat = globalFormat;
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116 | }
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117 |
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118 | /** sets the site home */
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119 | public void setSiteHome(String site_home)
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120 | {
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121 | this.site_home = site_home;
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122 | }
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123 |
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124 | /** sets the site http address */
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125 | public void setSiteAddress(String site_address)
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126 | {
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127 | this.site_http_address = site_address;
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128 | }
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129 |
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130 | public void setLibraryName(String library_name)
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131 | {
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132 | this.library_name = library_name;
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133 | }
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134 |
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135 | public String getLibraryName()
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136 | {
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137 | return this.library_name;
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138 | }
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139 |
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140 | /** sets the message router */
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141 | public void setMessageRouter(MessageRouter m)
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142 | {
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143 | this.router = m;
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144 | setLibraryName(m.getLibraryName());
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145 | }
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146 |
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147 | /** the no-args constructor */
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148 | public ServiceRack()
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149 | {
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150 | this.converter = new XMLConverter();
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151 | this.doc = this.converter.newDOM();
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152 | this.short_service_info = this.doc.createElement(GSXML.SERVICE_ELEM + GSXML.LIST_MODIFIER);
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153 | this.format_info_map = new HashMap<String, Node>();
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154 | }
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155 |
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156 | /**
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157 | * configure the service module
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158 | *
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159 | * @param info
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160 | * the XML node <serviceRack name="XXX"/> with name equal to the
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161 | * class name (of the subclass)
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162 | *
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163 | * must configure short_service_info_ and service_info_map_
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164 | * @return true if configured ok must be implemented in subclasses
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165 | */
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166 | public boolean configure(Element info)
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167 | {
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168 | return configure(info, null);
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169 | }
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170 |
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171 | public boolean configure(Element info, Element extra_info)
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172 | {
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173 | // set up the class loader
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174 | this.class_loader = new CollectionClassLoader(this.getClass().getClassLoader(), this.site_home, this.cluster_name);
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175 | return true;
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176 | }
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177 |
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178 | /**
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179 | * Process an XML document - convenience method that uses Strings rather
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180 | * than Elements. just calls process(Element).
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181 | *
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182 | * @param xml_in
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183 | * the Document to process - a string
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184 | * @return the resultant document as a string - contains any error messages
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185 | * @see String
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186 | */
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187 | public String process(String xml_in)
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188 | {
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189 |
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190 | Document doc = this.converter.getDOM(xml_in);
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191 | if (doc == null)
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192 | {
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193 | logger.error("Couldn't parse request");
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194 | logger.error(xml_in);
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195 | return null;
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196 | }
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197 | Node res = process(doc);
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198 | return this.converter.getString(res);
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199 |
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200 | }
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201 |
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202 | /**
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203 | * process an XML request in DOM form
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204 | *
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205 | * @param message
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206 | * the Node node containing the request should be <message>
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207 | * @return an Node with the result XML
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208 | * @see Node/Element
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209 | */
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210 | public Node process(Node message_node)
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211 | {
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212 | Element message = this.converter.nodeToElement(message_node);
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213 |
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214 | NodeList requests = message.getElementsByTagName(GSXML.REQUEST_ELEM);
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215 | Element mainResult = this.doc.createElement(GSXML.MESSAGE_ELEM);
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216 | if (requests.getLength() == 0)
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217 | {
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218 | // no requests
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219 | return mainResult; // empty message for now
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220 | }
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221 |
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222 | for (int i = 0; i < requests.getLength(); i++)
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223 | {
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224 | Element request = (Element) requests.item(i);
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225 |
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226 | String type = request.getAttribute(GSXML.TYPE_ATT);
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227 | if (type.equals(GSXML.REQUEST_TYPE_DESCRIBE))
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228 | {
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229 | Element response = processDescribe(request);
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230 | if (response != null)
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231 | {
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232 | mainResult.appendChild(this.doc.importNode(response, true));
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233 | }
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234 |
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235 | }
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236 | else if (type.equals(GSXML.REQUEST_TYPE_FORMAT))
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237 | {
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238 | Element response = processFormat(request);
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239 | mainResult.appendChild(this.doc.importNode(response, true));
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240 | }
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241 | else
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242 | {
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243 | // other type of request, must be processed by the subclass -
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244 | // send to the service method
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245 | StringBuffer error_string = new StringBuffer();
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246 | String to = GSPath.getFirstLink(request.getAttribute(GSXML.TO_ATT));
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247 | Element response = null;
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248 | try
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249 | {
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250 | Class c = this.getClass();
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251 | Class[] params = { Class.forName("org.w3c.dom.Element") };
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252 |
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253 | String method_name = "process" + to;
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254 | Method m = null;
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255 | while (c != null)
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256 | {
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257 |
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258 | try
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259 | {
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260 | m = c.getDeclaredMethod(method_name, params);
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261 | // if this has worked, break
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262 | break;
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263 | }
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264 | catch (NoSuchMethodException e)
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265 | {
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266 | c = c.getSuperclass();
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267 | }
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268 | catch (SecurityException e)
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269 | {
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270 | logger.error("security exception for finding method " + method_name);
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271 | error_string.append("ServiceRack.process: security exception for finding method " + method_name);
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272 | }
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273 | } // while
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274 | if (m != null)
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275 | {
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276 | Object[] args = { request };
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277 | try
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278 | {
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279 | response = (Element) m.invoke(this, args);
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280 |
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281 | }
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282 | catch (Exception e)
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283 | {
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284 | logger.error("Trying to call a processService type method (process" + to + ") on a subclass(" + this.getClass().getName() + "), but an exception happened:" + e.toString(), e);
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285 |
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286 | error_string.append("Trying to call a processService type method (process" + to + ") on a subclass(" + this.getClass().getName() + "), but an exception happened:" + e.toString());
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287 | }
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288 | }
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289 | else
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290 | {
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291 | logger.error("method " + method_name + " not found for class " + this.getClass().getName());
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292 | error_string.append("ServiceRack.process: method " + method_name + " not found for class " + this.getClass().getName());
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293 | }
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294 |
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295 | }
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296 | catch (ClassNotFoundException e)
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297 | {
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298 | logger.error("Element class not found");
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299 | error_string.append("Element class not found");
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300 | }
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301 | if (response != null)
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302 | {
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303 | mainResult.appendChild(this.doc.importNode(response, true));
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304 | }
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305 | else
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306 | {
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307 | // add in a dummy response
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308 | logger.error("adding in an error element\n");
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309 | response = this.doc.createElement(GSXML.RESPONSE_ELEM);
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310 | GSXML.addError(this.doc, response, error_string.toString());
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311 | mainResult.appendChild(response);
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312 |
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313 | }
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314 |
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315 | } // else process request
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316 | } // for each request
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317 |
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318 | return mainResult;
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319 |
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320 | }
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321 |
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322 | /**
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323 | * process method for describe requests
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324 | */
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325 | protected Element processDescribe(Element request)
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326 | {
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327 |
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328 | Element response = this.doc.createElement(GSXML.RESPONSE_ELEM);
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329 | response.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_DESCRIBE);
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330 |
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331 | String lang = request.getAttribute(GSXML.LANG_ATT);
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332 | String to = GSPath.getFirstLink(request.getAttribute(GSXML.TO_ATT));
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333 | if (to.equals(""))
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334 | { // return the service list
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335 | response.appendChild(getServiceList(lang));
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336 | return response;
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337 | }
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338 | response.setAttribute(GSXML.FROM_ATT, to);
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339 | Element param_list = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
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340 | Element description = null;
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341 | if (param_list == null)
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342 | {
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343 | description = getServiceDescription(to, lang, null);
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344 | }
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345 | else
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346 | {
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347 | NodeList params = param_list.getElementsByTagName(GSXML.PARAM_ELEM);
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348 | for (int i = 0; i < params.getLength(); i++)
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349 | {
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350 |
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351 | Element param = (Element) params.item(i);
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352 | // Identify the structure information desired
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353 | if (param.getAttribute(GSXML.NAME_ATT).equals(GSXML.SUBSET_PARAM))
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354 | {
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355 | String info = param.getAttribute(GSXML.VALUE_ATT);
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356 | if (description == null)
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357 | {
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358 | description = getServiceDescription(to, lang, info);
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359 | }
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360 | else
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361 | {
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362 | Element temp = getServiceDescription(to, lang, info);
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363 | GSXML.mergeElements(description, temp);
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364 | }
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365 | }
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366 | }
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367 | }
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368 | if (description != null)
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369 | { // may be null if non-existant service
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370 | response.appendChild(description);
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371 | }
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372 | return response;
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373 |
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374 | }
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375 |
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376 | /**
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377 | * process method for stylesheet requests
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378 | */
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379 | protected Element processFormat(Element request)
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380 | {
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381 | Element response = this.doc.createElement(GSXML.RESPONSE_ELEM);
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382 | response.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_FORMAT);
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383 |
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384 | String to = GSPath.getFirstLink(request.getAttribute(GSXML.TO_ATT));
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385 |
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386 | if (to.equals(""))
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387 | { // serviceRack query - is this appropriate??
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388 | return response;
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389 | }
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390 |
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391 | // describe a particular service
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392 | if (this.format_info_map.containsKey(to))
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393 | {
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394 | response.appendChild(response.getOwnerDocument().importNode(getServiceFormat(to), true));
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395 | if (_globalFormat != null)
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396 | {
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397 | response.appendChild(response.getOwnerDocument().importNode(GSXML.duplicateWithNewName(response.getOwnerDocument(), _globalFormat, GSXML.GLOBAL_FORMAT_ELEM, false), true));
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398 | }
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399 | response.setAttribute(GSXML.FROM_ATT, to);
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400 | return response;
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401 | }
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402 |
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403 | // else no format info
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404 | logger.error("ServiceRack describe request: no format info for " + to + ".");
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405 | return response;
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406 | }
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407 |
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408 | /** returns the service list for the subclass */
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409 | protected Element getServiceList(String lang)
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410 | {
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411 | // for now, it is static and has no language stuff
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412 | return (Element) this.short_service_info.cloneNode(true);
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413 | }
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414 |
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415 | /** returns a specific service description */
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416 | abstract protected Element getServiceDescription(String service, String lang, String subset);
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417 |
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418 | protected Element getServiceFormat(String service)
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419 | {
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420 | Element format = (Element) ((Element) this.format_info_map.get(service)).cloneNode(true);
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421 | return format;
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422 | }
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423 |
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424 | /** overloaded version for no args case */
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425 | protected String getTextString(String key, String lang)
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426 | {
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427 | return getTextString(key, lang, null, null);
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428 | }
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429 |
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430 | protected String getTextString(String key, String lang, String dictionary)
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431 | {
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432 | return getTextString(key, lang, dictionary, null);
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433 | }
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434 |
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435 | protected String getTextString(String key, String lang, String[] args)
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436 | {
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437 | return getTextString(key, lang, null, args);
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438 | }
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439 |
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440 | /**
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441 | * getTextString - retrieves a language specific text string for the given
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442 | * key and locale, from the specified resource_bundle (dictionary)
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443 | */
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444 | protected String getTextString(String key, String lang, String dictionary, String[] args)
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445 | {
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446 |
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447 | // we want to use the collection class loader in case there are coll specific files
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448 | if (dictionary != null)
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449 | {
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450 | // just try the one specified dictionary
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451 | Dictionary dict = new Dictionary(dictionary, lang, this.class_loader);
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452 | String result = dict.get(key, args);
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453 | if (result == null)
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454 | { // not found
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455 | return "_" + key + "_";
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456 | }
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457 | return result;
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458 | }
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459 |
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460 | // now we try class names for dictionary names
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461 | String class_name = this.getClass().getName();
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462 | class_name = class_name.substring(class_name.lastIndexOf('.') + 1);
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463 | Dictionary dict = new Dictionary(class_name, lang, this.class_loader);
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464 | String result = dict.get(key, args);
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465 | if (result != null)
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466 | {
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467 | return result;
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468 | }
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469 |
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470 | // we have to try super classes
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471 | Class c = this.getClass().getSuperclass();
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472 | while (result == null && c != null)
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473 | {
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474 | class_name = c.getName();
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475 | class_name = class_name.substring(class_name.lastIndexOf('.') + 1);
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476 | if (class_name.equals("ServiceRack"))
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477 | {
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478 | // this is as far as we go
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479 | break;
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480 | }
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481 | dict = new Dictionary(class_name, lang, this.class_loader);
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482 | result = dict.get(key, args);
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483 | c = c.getSuperclass();
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484 | }
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485 | if (result == null)
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486 | {
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487 | return "_" + key + "_";
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488 | }
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489 | return result;
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490 |
|
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491 | }
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492 |
|
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493 | protected String getMetadataNameText(String key, String lang)
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494 | {
|
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495 |
|
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496 | String properties_name = "metadata_names";
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497 | Dictionary dict = new Dictionary(properties_name, lang);
|
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498 |
|
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499 | String result = dict.get(key);
|
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500 | if (result == null)
|
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501 | { // not found
|
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502 | return null;
|
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503 | }
|
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504 | return result;
|
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505 | }
|
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506 | }
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