Package de.xima.fc.classloader

Class ChainedClassLoader

java.lang.Object
java.lang.ClassLoader
de.xima.fc.classloader.ChainedClassLoader
All Implemented Interfaces:
AutoCloseable
public final class ChainedClassLoader extends ClassLoader implements AutoCloseable
A class loader that combines several other class loaders.
  • When searching for a class, it tries each class loader in order, and returns the class of the first class loader that can provide the class.
  • When searching for a resources, it tries each class loader in order, and returns the resource of the first class loader that can provide the resource.
  • When searching for multiple resources, it returns the resources of all class loaders.
When this class loader is closed, all chained loaders are closed if they implement AutoCloseable. Afterwards, classes cannot be loaded anymore.
Since:
7.0.11
Author:
XIMA MEDIA GmbH

  • Constructor Details

    • ChainedClassLoader

      public ChainedClassLoader(ClassLoader[] classLoaders)
      Creates a new chained class loader that combines the given loaders.
      Parameters:
      classLoaders - Loaders to chain.

    • ChainedClassLoader

      public ChainedClassLoader(Iterable<ClassLoader> classLoaders)
      Creates a new chained class loader that combines the given loaders.
      Parameters:
      classLoaders - Loaders to chain.

  • Method Details

    • close

      public void close() throws Exception
      Closes all chained loaders if they implement AutoCloseable. Afterwards, classes cannot be loaded anymore.

      The method makes a best effort attempt to close all opened files, by catching Exceptions internally. Unchecked exceptions and errors are not caught. Calling close on an already closed loader has no effect.

      Specified by:
      close in interface AutoCloseable
      Throws:
      Exception - If closing any file opened by this class loader resulted in an Exception. Any such exceptions are caught internally. If only one is caught, then it is re-thrown. If more than one exception is caught, then the second and following exceptions are added as suppressed exceptions of the first one caught, which is then re-thrown.

    • getClassLoaders

      public List<ClassLoader> getClassLoaders()
      Returns all class loaders which this class loader combines. Note: the returned list is unmodifiable.
      Returns:
      The class loaders that are chained by this class loader.

    • getResource

      public URL getResource(String name)
      Overrides:
      getResource in class ClassLoader

    • getResources

      public Enumeration<URL> getResources(String name) throws IOException
      Overrides:
      getResources in class ClassLoader
      Throws:
      IOException

    • loadClass

      public Class<?> loadClass(String name) throws ClassNotFoundException
      Overrides:
      loadClass in class ClassLoader
      Throws:
      ClassNotFoundException

    • chain

      public static ClassLoader chain(ClassLoader[] classLoaders)
      Creates a new class loader that combines the given loaders. This method makes no guarantess regarding which sub class of ClassLoader is returned.
      Parameters:
      classLoaders - Loaders to chain.
      Returns:
      A class loader that combines the given loaders.

    • chain

      public static ClassLoader chain(Iterable<ClassLoader> classLoaders)
      Creates a new class loader that combines the given loaders. This method makes no guarantess regarding which sub class of ClassLoader is returned.
      Parameters:
      classLoaders - Loaders to chain.
      Returns:
      A class loader that combines the given loaders.