List of usage examples for javax.imageio.spi IIORegistry getServiceProviders
public <T> Iterator<T> getServiceProviders(Class<T> category, boolean useOrdering)
From source file:org.geoserver.GeoserverInitStartupListener.java
/** * This method tries hard to stop all threads and remove all references to classes in GeoServer * so that we can avoid permgen leaks on application undeploy. * What happes is that, if any JDK class references to one of the classes loaded by the * webapp classloader, then the classloader cannot be collected and neither can all the * classes loaded by it (since each class keeps a back reference to the classloader that * loaded it). The same happens for any residual thread launched by the web app. *///from w w w. j a v a 2 s.com public void contextDestroyed(ServletContextEvent sce) { try { LOGGER.info("Beginning GeoServer cleanup sequence"); // the dreaded classloader ClassLoader webappClassLoader = getClass().getClassLoader(); // unload all of the jdbc drivers we have loaded. We need to store them and unregister // later to avoid concurrent modification exceptions Enumeration<Driver> drivers = DriverManager.getDrivers(); Set<Driver> driversToUnload = new HashSet<Driver>(); while (drivers.hasMoreElements()) { Driver driver = drivers.nextElement(); try { // the driver class loader can be null if the driver comes from the JDK, such as the // sun.jdbc.odbc.JdbcOdbcDriver ClassLoader driverClassLoader = driver.getClass().getClassLoader(); if (driverClassLoader != null && webappClassLoader.equals(driverClassLoader)) { driversToUnload.add(driver); } } catch (Throwable t) { t.printStackTrace(); } } for (Driver driver : driversToUnload) { try { DriverManager.deregisterDriver(driver); LOGGER.info("Unregistered JDBC driver " + driver); } catch (Exception e) { LOGGER.log(Level.SEVERE, "Could now unload driver " + driver.getClass(), e); } } drivers = DriverManager.getDrivers(); while (drivers.hasMoreElements()) { Driver driver = drivers.nextElement(); } try { Class h2Driver = Class.forName("org.h2.Driver"); Method m = h2Driver.getMethod("unload"); m.invoke(null); } catch (Exception e) { LOGGER.log(Level.WARNING, "Failed to unload the H2 driver", e); } // unload all deferred authority factories so that we get rid of the timer tasks in them try { disposeAuthorityFactories(ReferencingFactoryFinder.getCoordinateOperationAuthorityFactories(null)); } catch (Throwable e) { LOGGER.log(Level.WARNING, "Error occurred trying to dispose authority factories", e); } try { disposeAuthorityFactories(ReferencingFactoryFinder.getCRSAuthorityFactories(null)); } catch (Throwable e) { LOGGER.log(Level.WARNING, "Error occurred trying to dispose authority factories", e); } try { disposeAuthorityFactories(ReferencingFactoryFinder.getCSAuthorityFactories(null)); } catch (Throwable e) { LOGGER.log(Level.WARNING, "Error occurred trying to dispose authority factories", e); } // kill the threads created by referencing WeakCollectionCleaner.DEFAULT.exit(); DeferredAuthorityFactory.exit(); CRS.reset("all"); LOGGER.info("Shut down GT referencing threads "); // reset ReferencingFactoryFinder.reset(); CommonFactoryFinder.reset(); DataStoreFinder.reset(); DataAccessFinder.reset(); LOGGER.info("Shut down GT SPI "); LOGGER.info("Shut down coverage thread pool "); Object o = Hints.getSystemDefault(Hints.EXECUTOR_SERVICE); if (o != null && o instanceof ExecutorService) { final ThreadPoolExecutor executor = (ThreadPoolExecutor) o; try { executor.shutdown(); } finally { try { executor.shutdownNow(); } finally { } } } // unload everything that JAI ImageIO can still refer to // We need to store them and unregister later to avoid concurrent modification exceptions final IIORegistry ioRegistry = IIORegistry.getDefaultInstance(); Set<IIOServiceProvider> providersToUnload = new HashSet(); for (Iterator<Class<?>> cats = ioRegistry.getCategories(); cats.hasNext();) { Class<?> category = cats.next(); for (Iterator it = ioRegistry.getServiceProviders(category, false); it.hasNext();) { final IIOServiceProvider provider = (IIOServiceProvider) it.next(); if (webappClassLoader.equals(provider.getClass().getClassLoader())) { providersToUnload.add(provider); } } } for (IIOServiceProvider provider : providersToUnload) { ioRegistry.deregisterServiceProvider(provider); LOGGER.info("Unregistering Image I/O provider " + provider); } // unload everything that JAI can still refer to final OperationRegistry opRegistry = JAI.getDefaultInstance().getOperationRegistry(); for (String mode : RegistryMode.getModeNames()) { for (Iterator descriptors = opRegistry.getDescriptors(mode).iterator(); descriptors != null && descriptors.hasNext();) { RegistryElementDescriptor red = (RegistryElementDescriptor) descriptors.next(); int factoryCount = 0; int unregisteredCount = 0; // look for all the factories for that operation for (Iterator factories = opRegistry.getFactoryIterator(mode, red.getName()); factories != null && factories.hasNext();) { Object factory = factories.next(); if (factory == null) { continue; } factoryCount++; if (webappClassLoader.equals(factory.getClass().getClassLoader())) { boolean unregistered = false; // we need to scan against all "products" to unregister the factory Vector orderedProductList = opRegistry.getOrderedProductList(mode, red.getName()); if (orderedProductList != null) { for (Iterator products = orderedProductList.iterator(); products != null && products.hasNext();) { String product = (String) products.next(); try { opRegistry.unregisterFactory(mode, red.getName(), product, factory); LOGGER.info("Unregistering JAI factory " + factory.getClass()); } catch (Throwable t) { // may fail due to the factory not being registered against that product } } } if (unregistered) { unregisteredCount++; } } } // if all the factories were unregistered, get rid of the descriptor as well if (factoryCount > 0 && unregisteredCount == factoryCount) { opRegistry.unregisterDescriptor(red); } } } // flush all javabean introspection caches as this too can keep a webapp classloader from being unloaded Introspector.flushCaches(); LOGGER.info("Cleaned up javabean caches"); // unload the logging framework if (!relinquishLoggingControl) LogManager.shutdown(); LogFactory.release(Thread.currentThread().getContextClassLoader()); // GeoTools/GeoServer have a lot of finalizers and until they are run the JVM // itself wil keepup the class loader... try { System.gc(); System.runFinalization(); System.gc(); System.runFinalization(); System.gc(); System.runFinalization(); } catch (Throwable t) { System.out.println("Failed to perform closing up finalization"); t.printStackTrace(); } } catch (Throwable t) { // if anything goes south during the cleanup procedures I want to know what it is t.printStackTrace(); } }