8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.xml.stream; 27 28 import java.io.InputStream; 29 import java.io.IOException; 30 import java.io.File; 31 import java.io.FileInputStream; 32 33 import java.util.Properties; 34 import java.io.BufferedReader; 35 import java.io.InputStreamReader; 36 37 /** 38 * <p>Implements pluggable Datatypes.</p> 39 * 40 * <p>This class is duplicated for each JAXP subpackage so keep it in 41 * sync. It is package private for secure class loading.</p> 42 * 43 * @author Santiago.PericasGeertsen@sun.com 44 */ 45 class FactoryFinder { 46 47 /** 48 * Internal debug flag. 49 */ 50 private static boolean debug = false; 51 52 /** 53 * Cache for properties in java.home/lib/jaxp.properties 54 */ 55 static Properties cacheProps = new Properties(); 56 57 /** 58 * Flag indicating if properties from java.home/lib/jaxp.properties 59 * have been cached. 60 */ 61 static volatile boolean firstTime = true; 62 63 /** 64 * Security support class use to check access control before 65 * getting certain system resources. 66 */ 67 static SecuritySupport ss = new SecuritySupport(); 68 69 // Define system property "jaxp.debug" to get output 70 static { 71 // Use try/catch block to support applets, which throws 72 // SecurityException out of this code. 73 try { 74 String val = ss.getSystemProperty("jaxp.debug"); 75 // Allow simply setting the prop to turn on debug 76 debug = val != null && !"false".equals(val); 77 } 78 catch (SecurityException se) { 79 debug = false; 80 } 81 } 82 83 private static void dPrint(String msg) { 84 if (debug) { 85 System.err.println("JAXP: " + msg); 86 } 87 } 88 89 /** 90 * Attempt to load a class using the class loader supplied. If that fails 91 * and fall back is enabled, the current (i.e. bootstrap) class loader is 92 * tried. 93 * 94 * If the class loader supplied is <code>null</code>, first try using the 95 * context class loader followed by the current (i.e. bootstrap) class 96 * loader. 97 */ 98 static private Class getProviderClass(String className, ClassLoader cl, 99 boolean doFallback) throws ClassNotFoundException 100 { 101 try { 102 if (cl == null) { 103 cl = ss.getContextClassLoader(); 104 if (cl == null) { 105 throw new ClassNotFoundException(); 106 } 107 else { 108 return cl.loadClass(className); 109 } 110 } 111 else { 112 return cl.loadClass(className); 113 } 114 } 115 catch (ClassNotFoundException e1) { 116 if (doFallback) { 117 // Use current class loader - should always be bootstrap CL 118 return Class.forName(className, true, FactoryFinder.class.getClassLoader()); 119 } 120 else { 121 throw e1; 122 } 123 } 124 } 125 126 /** 127 * Create an instance of a class. Delegates to method 128 * <code>getProviderClass()</code> in order to load the class. 129 * 130 * @param className Name of the concrete class corresponding to the 131 * service provider 132 * 133 * @param cl ClassLoader to use to load the class, null means to use 134 * the bootstrap ClassLoader 135 * 136 * @param doFallback True if the current ClassLoader should be tried as 137 * a fallback if the class is not found using cl 138 */ 139 static Object newInstance(String className, ClassLoader cl, boolean doFallback) 140 throws ConfigurationError 141 { 142 try { 143 Class providerClass = getProviderClass(className, cl, doFallback); 144 Object instance = providerClass.newInstance(); 145 if (debug) { // Extra check to avoid computing cl strings 146 dPrint("created new instance of " + providerClass + 147 " using ClassLoader: " + cl); 148 } 149 return instance; 150 } 151 catch (ClassNotFoundException x) { 152 throw new ConfigurationError( 153 "Provider " + className + " not found", x); 154 } 155 catch (Exception x) { 156 throw new ConfigurationError( 157 "Provider " + className + " could not be instantiated: " + x, 158 x); 159 } 160 } 161 162 /** 163 * Finds the implementation Class object in the specified order. 164 * 165 * @return Class object of factory, never null 166 * 167 * @param factoryId Name of the factory to find, same as 168 * a property name 169 * @param fallbackClassName Implementation class name, if nothing else 170 * is found. Use null to mean no fallback. 171 * 172 * Package private so this code can be shared. 173 */ 174 static Object find(String factoryId, String fallbackClassName) 175 throws ConfigurationError 176 { 177 return find(factoryId, null, fallbackClassName); 178 } 179 180 /** 181 * Finds the implementation Class object in the specified order. Main 182 * entry point. 183 * @return Class object of factory, never null 184 * 185 * @param factoryId Name of the factory to find, same as 186 * a property name 187 * 188 * @param cl ClassLoader to be used to load the class, null means to use 189 * the bootstrap ClassLoader 190 * 191 * @param fallbackClassName Implementation class name, if nothing else 192 * is found. Use null to mean no fallback. 193 * 194 * Package private so this code can be shared. 195 */ 196 static Object find(String factoryId, ClassLoader cl, String fallbackClassName) 197 throws ConfigurationError 198 { 199 dPrint("find factoryId =" + factoryId); 200 201 // Use the system property first 202 try { 203 String systemProp = ss.getSystemProperty(factoryId); 204 if (systemProp != null) { 205 dPrint("found system property, value=" + systemProp); 206 return newInstance(systemProp, null, true); 207 } 208 } 209 catch (SecurityException se) { 210 if (debug) se.printStackTrace(); 211 } 212 213 // Try read $java.home/lib/stax.properties followed by 214 // $java.home/lib/jaxp.properties if former not present 215 String configFile = null; 216 try { 217 String factoryClassName = null; 218 if (firstTime) { 219 synchronized (cacheProps) { 220 if (firstTime) { 221 configFile = ss.getSystemProperty("java.home") + File.separator + 222 "lib" + File.separator + "stax.properties"; 223 File f = new File(configFile); 224 firstTime = false; 225 if (ss.doesFileExist(f)) { 226 dPrint("Read properties file "+f); 227 cacheProps.load(ss.getFileInputStream(f)); 228 } 229 else { 230 configFile = ss.getSystemProperty("java.home") + File.separator + 231 "lib" + File.separator + "jaxp.properties"; 232 f = new File(configFile); 233 if (ss.doesFileExist(f)) { 234 dPrint("Read properties file "+f); 235 cacheProps.load(ss.getFileInputStream(f)); 236 } 237 } 238 } 239 } 240 } 241 factoryClassName = cacheProps.getProperty(factoryId); 242 243 if (factoryClassName != null) { 244 dPrint("found in " + configFile + " value=" + factoryClassName); 245 return newInstance(factoryClassName, null, true); 246 } 247 } 248 catch (Exception ex) { 249 if (debug) ex.printStackTrace(); 250 } 251 252 // Try Jar Service Provider Mechanism 253 Object provider = findJarServiceProvider(factoryId); 254 if (provider != null) { 255 return provider; 256 } 257 if (fallbackClassName == null) { 258 throw new ConfigurationError( 259 "Provider for " + factoryId + " cannot be found", null); 260 } 261 262 dPrint("loaded from fallback value: " + fallbackClassName); 263 return newInstance(fallbackClassName, cl, true); 264 } 265 266 /* 267 * Try to find provider using Jar Service Provider Mechanism 268 * 269 * @return instance of provider class if found or null 270 */ 271 private static Object findJarServiceProvider(String factoryId) 272 throws ConfigurationError 273 { 274 String serviceId = "META-INF/services/" + factoryId; 275 InputStream is = null; 276 277 // First try the Context ClassLoader 278 ClassLoader cl = ss.getContextClassLoader(); 279 if (cl != null) { 280 is = ss.getResourceAsStream(cl, serviceId); 281 282 // If no provider found then try the current ClassLoader 283 if (is == null) { 284 cl = FactoryFinder.class.getClassLoader(); 285 is = ss.getResourceAsStream(cl, serviceId); 286 } 287 } else { 288 // No Context ClassLoader, try the current ClassLoader 289 cl = FactoryFinder.class.getClassLoader(); 290 is = ss.getResourceAsStream(cl, serviceId); 291 } 292 293 if (is == null) { 294 // No provider found 295 return null; 296 } 297 298 if (debug) { // Extra check to avoid computing cl strings 299 dPrint("found jar resource=" + serviceId + " using ClassLoader: " + cl); 300 } 301 302 BufferedReader rd; 303 try { 304 rd = new BufferedReader(new InputStreamReader(is, "UTF-8")); 305 } 306 catch (java.io.UnsupportedEncodingException e) { 307 rd = new BufferedReader(new InputStreamReader(is)); 308 } 309 310 String factoryClassName = null; 311 try { 312 // XXX Does not handle all possible input as specified by the 313 // Jar Service Provider specification 314 factoryClassName = rd.readLine(); 315 rd.close(); 316 } catch (IOException x) { 317 // No provider found 318 return null; 319 } 320 321 if (factoryClassName != null && !"".equals(factoryClassName)) { 322 dPrint("found in resource, value=" + factoryClassName); 323 324 // Note: here we do not want to fall back to the current 325 // ClassLoader because we want to avoid the case where the 326 // resource file was found using one ClassLoader and the 327 // provider class was instantiated using a different one. 328 return newInstance(factoryClassName, cl, false); 329 } 330 331 // No provider found 332 return null; 333 } 334 335 static class ConfigurationError extends Error { 336 private Exception exception; 337 338 /** 339 * Construct a new instance with the specified detail string and 340 * exception. 341 */ 342 ConfigurationError(String msg, Exception x) { 343 super(msg); 344 this.exception = x; 345 } 346 347 Exception getException() { 348 return exception; 349 } 350 /** 351 * use the exception chaining mechanism of JDK1.4 352 */ 353 @Override 354 public Throwable getCause() { 355 return exception; 356 } 357 } 358 359 } | 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package javax.xml.stream; 27 28 import java.io.File; 29 import java.security.AccessController; 30 import java.security.PrivilegedAction; 31 import java.util.Iterator; 32 import java.util.Properties; 33 import java.util.ServiceConfigurationError; 34 import java.util.ServiceLoader; 35 36 /** 37 * <p>Implements pluggable Datatypes.</p> 38 * 39 * <p>This class is duplicated for each JAXP subpackage so keep it in 40 * sync. It is package private for secure class loading.</p> 41 * 42 * @author Santiago.PericasGeertsen@sun.com 43 */ 44 class FactoryFinder { 45 46 /** 47 * Internal debug flag. 48 */ 49 private static boolean debug = false; 50 51 /** 52 * Cache for properties in java.home/lib/jaxp.properties 53 */ 54 final static Properties cacheProps = new Properties(); 55 56 /** 57 * Flag indicating if properties from java.home/lib/jaxp.properties 58 * have been cached. 59 */ 60 static volatile boolean firstTime = true; 61 62 /** 63 * Security support class use to check access control before 64 * getting certain system resources. 65 */ 66 final static SecuritySupport ss = new SecuritySupport(); 67 68 // Define system property "jaxp.debug" to get output 69 static { 70 // Use try/catch block to support applets, which throws 71 // SecurityException out of this code. 72 try { 73 String val = ss.getSystemProperty("jaxp.debug"); 74 // Allow simply setting the prop to turn on debug 75 debug = val != null && !"false".equals(val); 76 } 77 catch (SecurityException se) { 78 debug = false; 79 } 80 } 81 82 private static void dPrint(String msg) { 83 if (debug) { 84 System.err.println("JAXP: " + msg); 85 } 86 } 87 88 /** 89 * Attempt to load a class using the class loader supplied. If that fails 90 * and fall back is enabled, the current (i.e. bootstrap) class loader is 91 * tried. 92 * 93 * If the class loader supplied is <code>null</code>, first try using the 94 * context class loader followed by the current (i.e. bootstrap) class 95 * loader. 96 */ 97 static private Class getProviderClass(String className, ClassLoader cl, 98 boolean doFallback) throws ClassNotFoundException 99 { 100 try { 101 if (cl == null) { 102 cl = ss.getContextClassLoader(); 103 if (cl == null) { 104 throw new ClassNotFoundException(); 105 } 106 else { 107 return Class.forName(className, false, cl); 108 } 109 } 110 else { 111 return Class.forName(className, false, cl); 112 } 113 } 114 catch (ClassNotFoundException e1) { 115 if (doFallback) { 116 // Use current class loader - should always be bootstrap CL 117 return Class.forName(className, false, FactoryFinder.class.getClassLoader()); 118 } 119 else { 120 throw e1; 121 } 122 } 123 } 124 125 /** 126 * Create an instance of a class. Delegates to method 127 * <code>getProviderClass()</code> in order to load the class. 128 * 129 * @param type Base class / Service interface of the factory to 130 * instantiate. 131 * 132 * @param className Name of the concrete class corresponding to the 133 * service provider 134 * 135 * @param cl ClassLoader to use to load the class, null means to use 136 * the bootstrap ClassLoader 137 * 138 * @param doFallback True if the current ClassLoader should be tried as 139 * a fallback if the class is not found using cl 140 */ 141 static <T> T newInstance(Class<T> type, String className, ClassLoader cl, 142 boolean doFallback) 143 throws FactoryConfigurationError 144 { 145 assert type != null; 146 try { 147 Class<?> providerClass = getProviderClass(className, cl, doFallback); 148 if (!type.isAssignableFrom(providerClass)) { 149 throw new ClassCastException(className + " cannot be cast to " + type.getName()); 150 } 151 Object instance = providerClass.newInstance(); 152 if (debug) { // Extra check to avoid computing cl strings 153 dPrint("created new instance of " + providerClass + 154 " using ClassLoader: " + cl); 155 } 156 return type.cast(instance); 157 } 158 catch (ClassNotFoundException x) { 159 throw new FactoryConfigurationError( 160 "Provider " + className + " not found", x); 161 } 162 catch (Exception x) { 163 throw new FactoryConfigurationError( 164 "Provider " + className + " could not be instantiated: " + x, 165 x); 166 } 167 } 168 169 /** 170 * Finds the implementation Class object in the specified order. 171 * 172 * @return Class object of factory, never null 173 * 174 * @param type Base class / Service interface of the 175 * factory to find. 176 * 177 * @param fallbackClassName Implementation class name, if nothing else 178 * is found. Use null to mean no fallback. 179 * 180 * Package private so this code can be shared. 181 */ 182 static <T> T find(Class<T> type, String fallbackClassName) 183 throws FactoryConfigurationError 184 { 185 return find(type, type.getName(), null, fallbackClassName); 186 } 187 188 /** 189 * Finds the implementation Class object in the specified order. Main 190 * entry point. 191 * @return Class object of factory, never null 192 * 193 * @param type Base class / Service interface of the 194 * factory to find. 195 * 196 * @param factoryId Name of the factory to find, same as 197 * a property name 198 * 199 * @param cl ClassLoader to be used to load the class, null means to use 200 * the bootstrap ClassLoader 201 * 202 * @param fallbackClassName Implementation class name, if nothing else 203 * is found. Use null to mean no fallback. 204 * 205 * Package private so this code can be shared. 206 */ 207 static <T> T find(Class<T> type, String factoryId, ClassLoader cl, String fallbackClassName) 208 throws FactoryConfigurationError 209 { 210 dPrint("find factoryId =" + factoryId); 211 212 // Use the system property first 213 try { 214 String systemProp = ss.getSystemProperty(factoryId); 215 if (systemProp != null) { 216 dPrint("found system property, value=" + systemProp); 217 // There's a bug here - because 'cl' is ignored. 218 // This will be handled separately. 219 return newInstance(type, systemProp, null, true); 220 } 221 } 222 catch (SecurityException se) { 223 if (debug) se.printStackTrace(); 224 } 225 226 // Try read $java.home/lib/stax.properties followed by 227 // $java.home/lib/jaxp.properties if former not present 228 String configFile = null; 229 try { 230 String factoryClassName; 231 if (firstTime) { 232 synchronized (cacheProps) { 233 if (firstTime) { 234 configFile = ss.getSystemProperty("java.home") + File.separator + 235 "lib" + File.separator + "stax.properties"; 236 File f = new File(configFile); 237 firstTime = false; 238 if (ss.doesFileExist(f)) { 239 dPrint("Read properties file "+f); 240 cacheProps.load(ss.getFileInputStream(f)); 241 } 242 else { 243 configFile = ss.getSystemProperty("java.home") + File.separator + 244 "lib" + File.separator + "jaxp.properties"; 245 f = new File(configFile); 246 if (ss.doesFileExist(f)) { 247 dPrint("Read properties file "+f); 248 cacheProps.load(ss.getFileInputStream(f)); 249 } 250 } 251 } 252 } 253 } 254 factoryClassName = cacheProps.getProperty(factoryId); 255 256 if (factoryClassName != null) { 257 dPrint("found in " + configFile + " value=" + factoryClassName); 258 // There's a bug here - because 'cl' is ignored. 259 // This will be handled separately. 260 return newInstance(type, factoryClassName, null, true); 261 } 262 } 263 catch (Exception ex) { 264 if (debug) ex.printStackTrace(); 265 } 266 267 // Try Jar Service Provider Mechanism 268 T provider = findServiceProvider(type); 269 if (provider != null) { 270 return provider; 271 } 272 if (fallbackClassName == null) { 273 throw new FactoryConfigurationError( 274 "Provider for " + factoryId + " cannot be found", null); 275 } 276 277 dPrint("loaded from fallback value: " + fallbackClassName); 278 return newInstance(type, fallbackClassName, cl, true); 279 } 280 281 /* 282 * Try to find provider using the ServiceLoader API 283 * 284 * @param type Base class / Service interface of the factory to find. 285 * 286 * @return instance of provider class if found or null 287 */ 288 private static <T> T findServiceProvider(final Class<T> type) { 289 try { 290 return AccessController.doPrivileged(new PrivilegedAction<T>() { 291 public T run() { 292 final ServiceLoader<T> serviceLoader = ServiceLoader.load(type); 293 final Iterator<T> iterator = serviceLoader.iterator(); 294 if (iterator.hasNext()) { 295 return iterator.next(); 296 } else { 297 return null; 298 } 299 } 300 }); 301 } catch(ServiceConfigurationError e) { 302 // It is not possible to wrap an error directly in 303 // FactoryConfigurationError - so we need to wrap the 304 // ServiceConfigurationError in a RuntimeException. 305 // The alternative would be to modify the logic in 306 // FactoryConfigurationError to allow setting a 307 // Throwable as the cause, but that could cause 308 // compatibility issues down the road. 309 final RuntimeException x = new RuntimeException( 310 "Provider for " + type + " cannot be created", e); 311 final FactoryConfigurationError error = 312 new FactoryConfigurationError(x, x.getMessage()); 313 throw error; 314 } 315 } 316 317 } |