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25 package org.ofbiz.base.config;
26
27 import java.io.InputStream  ;
28 import java.net.URL ;
29
30 import org.ofbiz.base.util.Debug;
31 import org.ofbiz.base.util.UtilURL;
32 import org.ofbiz.base.util.UtilXml;
33 import org.ofbiz.base.util.cache.UtilCache;
34 import org.w3c.dom.Document ;
35 import org.w3c.dom.Element ;
36
37
44 public abstract class ResourceLoader {
45
46 public static final String module = ResourceLoader.class.getName();
47 protected static UtilCache loaderCache = new UtilCache("resource.ResourceLoaders", 0, 0);
48
49 protected String name;
50 protected String prefix;
51 protected String envName;
52
53 public static InputStream loadResource(String xmlFilename, String location, String loaderName) throws GenericConfigException {
54 ResourceLoader loader = getLoader(xmlFilename, loaderName);
55 if (loader == null) {
56 throw new IllegalArgumentException ("ResourceLoader not found with name [" + loaderName + "] in " + xmlFilename);
57 }
58 return loader.loadResource(location);
59 }
60
61 public static URL getURL(String xmlFilename, String location, String loaderName) throws GenericConfigException {
62 ResourceLoader loader = getLoader(xmlFilename, loaderName);
63 if (loader == null) {
64 throw new IllegalArgumentException ("ResourceLoader not found with name [" + loaderName + "] in " + xmlFilename);
65 }
66 return loader.getURL(location);
67 }
68
69 public static ResourceLoader getLoader(String xmlFilename, String loaderName) throws GenericConfigException {
70 ResourceLoader loader = (ResourceLoader) loaderCache.get(xmlFilename + "::" + loaderName);
71
72 if (loader == null) {
73 synchronized (ResourceLoader.class) {
74 loader = (ResourceLoader) loaderCache.get(xmlFilename + "::" + loaderName);
75 if (loader == null) {
76 Element rootElement = getXmlRootElement(xmlFilename);
77
78 Element loaderElement = UtilXml.firstChildElement(rootElement, "resource-loader", "name", loaderName);
79
80 loader = makeLoader(loaderElement);
81
82 if (loader != null) {
83 loaderCache.put(xmlFilename + "::" + loaderName, loader);
84 }
85 }
86 }
87 }
88
89 return loader;
90 }
91
92 public static Element getXmlRootElement(String xmlFilename) throws GenericConfigException {
93 Document document = ResourceLoader.getXmlDocument(xmlFilename);
94
95 if (document != null) {
96 return document.getDocumentElement();
97 } else {
98 return null;
99 }
100 }
101
102 public static void invalidateDocument(String xmlFilename) throws GenericConfigException {
103 UtilCache.clearCachesThatStartWith(xmlFilename);
104 }
105
106 public static Document getXmlDocument(String xmlFilename) throws GenericConfigException {
107 Document document = (Document ) loaderCache.get(xmlFilename);
108
109 if (document == null) {
110 synchronized (ResourceLoader.class) {
111 document = (Document ) loaderCache.get(xmlFilename);
112 if (document == null) {
113 URL confUrl = UtilURL.fromResource(xmlFilename);
114
115 if (confUrl == null) {
116 throw new GenericConfigException("ERROR: could not find the [" + xmlFilename + "] XML file on the classpath");
117 }
118
119 try {
120 document = UtilXml.readXmlDocument(confUrl);
121 } catch (org.xml.sax.SAXException e) {
122 throw new GenericConfigException("Error reading " + xmlFilename + "", e);
123 } catch (javax.xml.parsers.ParserConfigurationException e) {
124 throw new GenericConfigException("Error reading " + xmlFilename + "", e);
125 } catch (java.io.IOException e) {
126 throw new GenericConfigException("Error reading " + xmlFilename + "", e);
127 }
128
129 if (document != null) {
130 loaderCache.put(xmlFilename, document);
131 }
132 }
133 }
134 }
135 return document;
136 }
137
138 public static ResourceLoader makeLoader(Element loaderElement) throws GenericConfigException {
139 if (loaderElement == null)
140 return null;
141
142 String loaderName = loaderElement.getAttribute("name");
143 String className = loaderElement.getAttribute("class");
144 ResourceLoader loader = null;
145
146 try {
147 Class lClass = null;
148
149 if (className != null && className.length() > 0) {
150 try {
151 ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
152 lClass = classLoader.loadClass(className);
153 } catch (ClassNotFoundException e) {
154 throw new GenericConfigException("Error loading Resource Loader class \"" + className + "\"", e);
155 }
156 }
157
158 try {
159 loader = (ResourceLoader) lClass.newInstance();
160 } catch (IllegalAccessException e) {
161 throw new GenericConfigException("Error loading Resource Loader class \"" + className + "\"", e);
162 } catch (InstantiationException e) {
163 throw new GenericConfigException("Error loading Resource Loader class \"" + className + "\"", e);
164 }
165 } catch (SecurityException e) {
166 throw new GenericConfigException("Error loading Resource Loader class \"" + className + "\"", e);
167 }
168
169 if (loader != null) {
170 loader.init(loaderName, loaderElement.getAttribute("prefix"), loaderElement.getAttribute("prepend-env"));
171 }
172
173 return loader;
174 }
175
176 protected ResourceLoader() {}
177
178 public void init(String name, String prefix, String envName) {
179 this.name = name;
180 this.prefix = prefix;
181 this.envName = envName;
182 }
183
184
188 public String fullLocation(String location) {
189 StringBuffer buf = new StringBuffer ();
190
191 if (envName != null && envName.length() > 0) {
192 String propValue = System.getProperty(envName);
193 if (propValue == null) {
194 String errMsg = "The Java environment (-Dxxx=yyy) variable with name " + envName + " is not set, cannot load resource.";
195 Debug.logError(errMsg, module);
196 throw new IllegalArgumentException (errMsg);
197 }
198 buf.append(propValue);
199 }
200 if (prefix != null && prefix.length() > 0) {
201 buf.append(prefix);
202 }
203 buf.append(location);
204 return buf.toString();
205 }
206
207 public abstract InputStream loadResource(String location) throws GenericConfigException;
208 public abstract URL getURL(String location) throws GenericConfigException;
209 }
210 |
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