| 1 | /* |
| 2 | |
| 3 | Derby - Class org.apache.derby.impl.services.reflect.DatabaseClasses |
| 4 | |
| 5 | Copyright 1998, 2004 The Apache Software Foundation or its licensors, as applicable. |
| 6 | |
| 7 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 8 | you may not use this file except in compliance with the License. |
| 9 | You may obtain a copy of the License at |
| 10 | |
| 11 | http://www.apache.org/licenses/LICENSE-2.0 |
| 12 | |
| 13 | Unless required by applicable law or agreed to in writing, software |
| 14 | distributed under the License is distributed on an "AS IS" BASIS, |
| 15 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 16 | See the License for the specific language governing permissions and |
| 17 | limitations under the License. |
| 18 | |
| 19 | */ |
| 20 | |
| 21 | package org.apache.derby.impl.services.reflect; |
| 22 | |
| 23 | import org.apache.derby.iapi.services.sanity.SanityManager; |
| 24 | |
| 25 | import org.apache.derby.iapi.services.loader.ClassFactory; |
| 26 | import org.apache.derby.iapi.services.loader.GeneratedClass; |
| 27 | import org.apache.derby.iapi.services.loader.ClassInspector; |
| 28 | |
| 29 | import org.apache.derby.iapi.services.monitor.ModuleControl; |
| 30 | import org.apache.derby.iapi.services.monitor.ModuleSupportable; |
| 31 | import org.apache.derby.iapi.services.monitor.Monitor; |
| 32 | |
| 33 | import org.apache.derby.iapi.error.StandardException; |
| 34 | import org.apache.derby.iapi.services.property.PropertyUtil; |
| 35 | |
| 36 | import org.apache.derby.iapi.services.stream.HeaderPrintWriter; |
| 37 | import org.apache.derby.iapi.services.monitor.Monitor; |
| 38 | |
| 39 | import org.apache.derby.iapi.services.compiler.*; |
| 40 | import java.lang.reflect.Modifier; |
| 41 | import org.apache.derby.iapi.sql.compile.CodeGeneration; |
| 42 | |
| 43 | import org.apache.derby.iapi.util.ByteArray; |
| 44 | import org.apache.derby.iapi.services.io.FileUtil; |
| 45 | import org.apache.derby.iapi.services.i18n.MessageService; |
| 46 | import org.apache.derby.iapi.reference.Property; |
| 47 | import org.apache.derby.iapi.reference.SQLState; |
| 48 | import org.apache.derby.iapi.reference.MessageId; |
| 49 | import org.apache.derby.iapi.reference.ClassName; |
| 50 | |
| 51 | import java.util.Properties; |
| 52 | import java.util.Hashtable; |
| 53 | |
| 54 | import java.io.ObjectStreamClass; |
| 55 | import java.io.File; |
| 56 | import java.io.FileOutputStream; |
| 57 | import java.io.IOException; |
| 58 | import java.io.Serializable; |
| 59 | |
| 60 | /** |
| 61 | |
| 62 | An abstract implementation of the ClassFactory. This package can |
| 63 | be extended to fully implement a ClassFactory. Implementations can |
| 64 | differ in two areas, how they load a class and how they invoke methods |
| 65 | of the generated class. |
| 66 | |
| 67 | <P> |
| 68 | This class manages a hash table of loaded generated classes and |
| 69 | their GeneratedClass objects. A loaded class may be referenced |
| 70 | multiple times -- each class has a reference count associated |
| 71 | with it. When a load request arrives, if the class has already |
| 72 | been loaded, its ref count is incremented. For a remove request, |
| 73 | the ref count is decremented unless it is the last reference, |
| 74 | in which case the class is removed. This is transparent to users. |
| 75 | |
| 76 | @see org.apache.derby.iapi.services.loader.ClassFactory |
| 77 | */ |
| 78 | |
| 79 | abstract class DatabaseClasses |
| 80 | implements ClassFactory, ModuleControl |
| 81 | { |
| 82 | /* |
| 83 | ** Fields |
| 84 | */ |
| 85 | |
| 86 | private ClassInspector classInspector; |
| 87 | private JavaFactory javaFactory; |
| 88 | |
| 89 | private UpdateLoader applicationLoader; |
| 90 | |
| 91 | /* |
| 92 | ** Constructor |
| 93 | */ |
| 94 | |
| 95 | DatabaseClasses() { |
| 96 | } |
| 97 | |
| 98 | /* |
| 99 | ** Public methods of ModuleControl |
| 100 | */ |
| 101 | |
| 102 | public void boot(boolean create, Properties startParams) |
| 103 | throws StandardException |
| 104 | { |
| 105 | |
| 106 | classInspector = new ClassInspector(this); |
| 107 | |
| 108 | // |
| 109 | //The ClassFactory runs per service (database) mode (booted as a service module after AccessFactory). |
| 110 | //If the code that booted |
| 111 | //us needs a per-database classpath then they pass in the classpath using |
| 112 | //the runtime property BOOT_DB_CLASSPATH in startParams |
| 113 | |
| 114 | |
| 115 | String classpath = null; |
| 116 | if (startParams != null) { |
| 117 | classpath = startParams.getProperty(Property.BOOT_DB_CLASSPATH); |
| 118 | } |
| 119 | |
| 120 | if (classpath != null) { |
| 121 | applicationLoader = new UpdateLoader(classpath, this, true, |
| 122 | true); |
| 123 | } |
| 124 | |
| 125 | javaFactory = (JavaFactory) org.apache.derby.iapi.services.monitor.Monitor.startSystemModule(org.apache.derby.iapi.reference.Module.JavaFactory); |
| 126 | } |
| 127 | |
| 128 | |
| 129 | |
| 130 | public void stop() { |
| 131 | if (applicationLoader != null) |
| 132 | applicationLoader.close(); |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | ** Public methods of ClassFactory |
| 137 | */ |
| 138 | |
| 139 | /** |
| 140 | Here we load the newly added class now, rather than waiting for the |
| 141 | findGeneratedClass(). Thus we are assuming that the class is going |
| 142 | to be used sometime soon. Delaying the load would mean storing the class |
| 143 | data in a file, this wastes cycles and compilcates the cleanup. |
| 144 | |
| 145 | @see ClassFactory#loadGeneratedClass |
| 146 | |
| 147 | @exception StandardException Class format is bad. |
| 148 | */ |
| 149 | public final GeneratedClass loadGeneratedClass(String fullyQualifiedName, ByteArray classDump) |
| 150 | throws StandardException { |
| 151 | |
| 152 | |
| 153 | try { |
| 154 | |
| 155 | |
| 156 | return loadGeneratedClassFromData(fullyQualifiedName, classDump); |
| 157 | |
| 158 | } catch (LinkageError le) { |
| 159 | |
| 160 | WriteClassFile(fullyQualifiedName, classDump, le); |
| 161 | |
| 162 | throw StandardException.newException(SQLState.GENERATED_CLASS_LINKAGE_ERROR, |
| 163 | le, fullyQualifiedName); |
| 164 | |
| 165 | } catch (VirtualMachineError vme) { // these may be beyond saving, but fwiw |
| 166 | |
| 167 | WriteClassFile(fullyQualifiedName, classDump, vme); |
| 168 | |
| 169 | throw vme; |
| 170 | } |
| 171 | |
| 172 | } |
| 173 | |
| 174 | private static void WriteClassFile(String fullyQualifiedName, ByteArray bytecode, Throwable t) { |
| 175 | |
| 176 | // get the un-qualified name and add the extension |
| 177 | int lastDot = fullyQualifiedName.lastIndexOf((int)'.'); |
| 178 | String filename = fullyQualifiedName.substring(lastDot+1,fullyQualifiedName.length()).concat(".class"); |
| 179 | |
| 180 | Object env = Monitor.getMonitor().getEnvironment(); |
| 181 | File dir = env instanceof File ? (File) env : null; |
| 182 | |
| 183 | File classFile = FileUtil.newFile(dir,filename); |
| 184 | |
| 185 | // find the error stream |
| 186 | HeaderPrintWriter errorStream = Monitor.getStream(); |
| 187 | |
| 188 | try { |
| 189 | FileOutputStream fis = new FileOutputStream(classFile); |
| 190 | fis.write(bytecode.getArray(), |
| 191 | bytecode.getOffset(), bytecode.getLength()); |
| 192 | fis.flush(); |
| 193 | if (t!=null) { |
| 194 | errorStream.printlnWithHeader(MessageService.getTextMessage(MessageId.CM_WROTE_CLASS_FILE, fullyQualifiedName, classFile, t)); |
| 195 | } |
| 196 | fis.close(); |
| 197 | } catch (IOException e) { |
| 198 | if (SanityManager.DEBUG) |
| 199 | SanityManager.THROWASSERT("Unable to write .class file"); |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | public ClassInspector getClassInspector() { |
| 204 | return classInspector; |
| 205 | } |
| 206 | |
| 207 | |
| 208 | public final Class loadApplicationClass(String className) |
| 209 | throws ClassNotFoundException { |
| 210 | |
| 211 | if (className.startsWith("org.apache.derby.")) { |
| 212 | // Assume this is an engine class, if so |
| 213 | // try to load from this class loader, |
| 214 | // this ensures in strange class loader |
| 215 | // environments we do not get ClassCastExceptions |
| 216 | // when an engine class is loaded through a different |
| 217 | // class loader to the rest of the engine. |
| 218 | try { |
| 219 | return Class.forName(className); |
| 220 | } catch (ClassNotFoundException cnfe) |
| 221 | { |
| 222 | // fall through to the code below, |
| 223 | // could be client or tools class |
| 224 | // in a different loader. |
| 225 | } |
| 226 | } |
| 227 | |
| 228 | Throwable loadError; |
| 229 | try { |
| 230 | try { |
| 231 | return loadClassNotInDatabaseJar(className); |
| 232 | } catch (ClassNotFoundException cnfe) { |
| 233 | if (applicationLoader == null) |
| 234 | throw cnfe; |
| 235 | Class c = applicationLoader.loadClass(className, true); |
| 236 | if (c == null) |
| 237 | throw cnfe; |
| 238 | return c; |
| 239 | } |
| 240 | } |
| 241 | catch (SecurityException se) |
| 242 | { |
| 243 | // Thrown if the class has been comprimised in some |
| 244 | // way, e.g. modified in a signed jar. |
| 245 | loadError = se; |
| 246 | } |
| 247 | catch (LinkageError le) |
| 248 | { |
| 249 | // some error linking the jar, again could |
| 250 | // be malicious code inserted into a jar. |
| 251 | loadError = le; |
| 252 | } |
| 253 | throw new ClassNotFoundException(className + " : " + loadError.getMessage()); |
| 254 | } |
| 255 | |
| 256 | abstract Class loadClassNotInDatabaseJar(String className) |
| 257 | throws ClassNotFoundException; |
| 258 | |
| 259 | public final Class loadApplicationClass(ObjectStreamClass classDescriptor) |
| 260 | throws ClassNotFoundException { |
| 261 | return loadApplicationClass(classDescriptor.getName()); |
| 262 | } |
| 263 | |
| 264 | public boolean isApplicationClass(Class theClass) { |
| 265 | |
| 266 | return theClass.getClassLoader() |
| 267 | instanceof JarLoader; |
| 268 | } |
| 269 | |
| 270 | public void notifyModifyJar(boolean reload) throws StandardException { |
| 271 | if (applicationLoader != null) { |
| 272 | applicationLoader.modifyJar(reload); |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | /** |
| 277 | Notify the class manager that the classpath has been modified. |
| 278 | |
| 279 | @exception StandardException thrown on error |
| 280 | */ |
| 281 | public void notifyModifyClasspath(String classpath) throws StandardException { |
| 282 | |
| 283 | if (applicationLoader != null) { |
| 284 | applicationLoader.modifyClasspath(classpath); |
| 285 | } |
| 286 | } |
| 287 | |
| 288 | |
| 289 | public int getClassLoaderVersion() { |
| 290 | if (applicationLoader != null) { |
| 291 | return applicationLoader.getClassLoaderVersion(); |
| 292 | } |
| 293 | |
| 294 | return -1; |
| 295 | } |
| 296 | |
| 297 | public ByteArray buildSpecificFactory(String className, String factoryName) |
| 298 | throws StandardException { |
| 299 | |
| 300 | ClassBuilder cb = javaFactory.newClassBuilder(this, CodeGeneration.GENERATED_PACKAGE_PREFIX, |
| 301 | Modifier.PUBLIC | Modifier.FINAL, factoryName, "org.apache.derby.impl.services.reflect.GCInstanceFactory"); |
| 302 | |
| 303 | MethodBuilder constructor = cb.newConstructorBuilder(Modifier.PUBLIC); |
| 304 | |
| 305 | constructor.callSuper(); |
| 306 | constructor.methodReturn(); |
| 307 | constructor.complete(); |
| 308 | constructor = null; |
| 309 | |
| 310 | MethodBuilder noArg = cb.newMethodBuilder(Modifier.PUBLIC, ClassName.GeneratedByteCode, "getNewInstance"); |
| 311 | noArg.pushNewStart(className); |
| 312 | noArg.pushNewComplete(0); |
| 313 | noArg.methodReturn(); |
| 314 | noArg.complete(); |
| 315 | noArg = null; |
| 316 | |
| 317 | return cb.getClassBytecode(); |
| 318 | } |
| 319 | |
| 320 | /* |
| 321 | ** Class specific methods |
| 322 | */ |
| 323 | |
| 324 | /* |
| 325 | ** Keep track of loaded generated classes and their GeneratedClass objects. |
| 326 | */ |
| 327 | |
| 328 | abstract LoadedGeneratedClass loadGeneratedClassFromData(String fullyQualifiedName, ByteArray classDump); |
| 329 | } |