Interface ClassLoaderRepository
-
public interface ClassLoaderRepositoryInstances of this interface are used to keep the list of ClassLoaders registered in an MBean Server. They provide the necessary methods to load classes using the registered ClassLoaders.
The first ClassLoader in a
ClassLoaderRepositoryis always the MBean Server's own ClassLoader.When an MBean is registered in an MBean Server, if it is of a subclass of
ClassLoaderand if it does not implement the interfacePrivateClassLoader, it is added to the end of the MBean Server'sClassLoaderRepository. If it is subsequently unregistered from the MBean Server, it is removed from theClassLoaderRepository.The order of MBeans in the
ClassLoaderRepositoryis significant. For any two MBeans X and Y in theClassLoaderRepository, X must appear before Y if the registration of X was completed before the registration of Y started. If X and Y were registered concurrently, their order is indeterminate. The registration of an MBean corresponds to the call toMBeanServer.registerMBean(java.lang.Object, javax.management.ObjectName)or one of theMBeanServer.createMBeanmethods.- Since:
- 1.5
- See Also:
-
MBeanServerFactory
-
-
Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method and Description Class<?>loadClass(String className)Load the given class name through the list of class loaders.Class<?>loadClassBefore(ClassLoader stop, String className)Load the given class name through the list of class loaders, stopping at the given one.Class<?>loadClassWithout(ClassLoader exclude, String className)Load the given class name through the list of class loaders, excluding the given one.
-
-
-
Method Detail
loadClass
Class<?> loadClass(String className) throws ClassNotFoundException
Load the given class name through the list of class loaders. Each ClassLoader in turn from the ClassLoaderRepository is asked to load the class via its
ClassLoader.loadClass(String)method. If it successfully returns aClassobject, that is the result of this method. If it throws aClassNotFoundException, the search continues with the next ClassLoader. If it throws another exception, the exception is propagated from this method. If the end of the list is reached, aClassNotFoundExceptionis thrown.- Parameters:
-
className- The name of the class to be loaded. - Returns:
- the loaded class.
- Throws:
-
ClassNotFoundException- The specified class could not be found.
loadClassWithout
Class<?> loadClassWithout(ClassLoader exclude, String className) throws ClassNotFoundException
Load the given class name through the list of class loaders, excluding the given one. Each ClassLoader in turn from the ClassLoaderRepository, except
exclude, is asked to load the class via itsClassLoader.loadClass(String)method. If it successfully returns aClassobject, that is the result of this method. If it throws aClassNotFoundException, the search continues with the next ClassLoader. If it throws another exception, the exception is propagated from this method. If the end of the list is reached, aClassNotFoundExceptionis thrown.Be aware that if a ClassLoader in the ClassLoaderRepository calls this method from its
loadClassmethod, it exposes itself to a deadlock if another ClassLoader in the ClassLoaderRepository does the same thing at the same time. TheloadClassBefore(java.lang.ClassLoader, java.lang.String)method is recommended to avoid the risk of deadlock.- Parameters:
-
className- The name of the class to be loaded. -
exclude- The class loader to be excluded. May be null, in which case this method is equivalent toloadClass(className). - Returns:
- the loaded class.
- Throws:
-
ClassNotFoundException- The specified class could not be found.
loadClassBefore
Class<?> loadClassBefore(ClassLoader stop, String className) throws ClassNotFoundException
Load the given class name through the list of class loaders, stopping at the given one. Each ClassLoader in turn from the ClassLoaderRepository is asked to load the class via its
ClassLoader.loadClass(String)method. If it successfully returns aClassobject, that is the result of this method. If it throws aClassNotFoundException, the search continues with the next ClassLoader. If it throws another exception, the exception is propagated from this method. If the search reachesstopor the end of the list, aClassNotFoundExceptionis thrown.Typically this method is called from the
loadClassmethod ofstop, to consult loaders that appear before it in theClassLoaderRepository. By stopping the search as soon asstopis reached, a potential deadlock with concurrent class loading is avoided.- Parameters:
-
className- The name of the class to be loaded. -
stop- The class loader at which to stop. May be null, in which case this method is equivalent toloadClass(className). - Returns:
- the loaded class.
- Throws:
-
ClassNotFoundException- The specified class could not be found.
-
Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2022, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.
