Example usage for javax.imageio.spi IIOServiceProvider getClass

List of usage examples for javax.imageio.spi IIOServiceProvider getClass

Introduction

In this page you can find the example usage for javax.imageio.spi IIOServiceProvider getClass.

Prototype

@HotSpotIntrinsicCandidate
public final native Class<?> getClass();

Source Link

Document

Returns the runtime class of this Object .

Usage

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  2s.  co  m
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();
    }
}