OpenJDK 1.23 · javax.management.loading.ClassLoaderRepository

Instances 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 ClassLoaderRepository is always the MBean Server's own ClassLoader.

When an MBean is registered in an MBean Server, if it is of a subclass of java.lang.ClassLoader and if it does not implement the interface PrivateClassLoader, it is added to the end of the MBean Server's ClassLoaderRepository. If it is subsequently unregistered from the MBean Server, it is removed from the ClassLoaderRepository.

The order of MBeans in the ClassLoaderRepository is significant. For any two MBeans X and Y in the ClassLoaderRepository, 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 to MBeanServer#registerMBean or one of the MBeanServer.createMBean methods.

Method Summary

Modifier and Type	Method and Description
public Class<?>	Returns: the loaded class. loadClass(String The name of the class to be loaded. className) Load the given class name through the list of class loaders.
public Class<?>	Returns: the loaded class. loadClassBefore(ClassLoader The class loader at which to stop. May be null, in which case this method is equivalent to `loadClass(className)`. stop, String The name of the class to be loaded. className) Load the given class name through the list of class loaders, stopping at the given one.
public Class<?>	Returns: the loaded class. loadClassWithout(ClassLoader The class loader to be excluded. May be null, in which case this method is equivalent to `loadClass(className)`. exclude, String The name of the class to be loaded. className) Load the given class name through the list of class loaders, excluding the given one.

Method Detail

loadClass back to summary

loadClass	back to summary
public 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 a `Class` object, that is the result of this method. If it throws a `ClassNotFoundException`, 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, a `ClassNotFoundException` is thrown. Parameters className:String The name of the class to be loaded. Returns:Class<?> the loaded class. Exceptions ClassNotFoundException: The specified class could not be found.

public 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 a Class object, that is the result of this method. If it throws a ClassNotFoundException, 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, a ClassNotFoundException is thrown.

Parameters

className:String: The name of the class to be loaded.

Returns:Class<?>

the loaded class.

Exceptions

ClassNotFoundException:: The specified class could not be found.

loadClassBefore back to summary

loadClassBefore	back to summary
public 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 a `Class` object, that is the result of this method. If it throws a `ClassNotFoundException`, the search continues with the next ClassLoader. If it throws another exception, the exception is propagated from this method. If the search reaches `stop` or the end of the list, a `ClassNotFoundException` is thrown. Typically this method is called from the `loadClass` method of `stop`, to consult loaders that appear before it in the `ClassLoaderRepository`. By stopping the search as soon as `stop` is reached, a potential deadlock with concurrent class loading is avoided. Parameters stop:ClassLoader The class loader at which to stop. May be null, in which case this method is equivalent to `loadClass(className)`. className:String The name of the class to be loaded. Returns:Class<?> the loaded class. Exceptions ClassNotFoundException: The specified class could not be found.

public 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 a Class object, that is the result of this method. If it throws a ClassNotFoundException, the search continues with the next ClassLoader. If it throws another exception, the exception is propagated from this method. If the search reaches stop or the end of the list, a ClassNotFoundException is thrown.

Typically this method is called from the loadClass method of stop, to consult loaders that appear before it in the ClassLoaderRepository. By stopping the search as soon as stop is reached, a potential deadlock with concurrent class loading is avoided.

Parameters

stop:ClassLoader: The class loader at which to stop. May be null, in which case this method is equivalent to loadClass(className).
className:String: The name of the class to be loaded.

Returns:Class<?>

the loaded class.

Exceptions

ClassNotFoundException:: The specified class could not be found.

loadClassWithout back to summary

loadClassWithout	back to summary
public 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 its `ClassLoader#loadClass(String)` method. If it successfully returns a `Class` object, that is the result of this method. If it throws a `ClassNotFoundException`, 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, a `ClassNotFoundException` is thrown. Be aware that if a ClassLoader in the ClassLoaderRepository calls this method from its `loadClass` method, it exposes itself to a deadlock if another ClassLoader in the ClassLoaderRepository does the same thing at the same time. The `loadClassBefore` method is recommended to avoid the risk of deadlock. Parameters exclude:ClassLoader The class loader to be excluded. May be null, in which case this method is equivalent to `loadClass(className)`. className:String The name of the class to be loaded. Returns:Class<?> the loaded class. Exceptions ClassNotFoundException: The specified class could not be found.

public 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 its ClassLoader#loadClass(String) method. If it successfully returns a Class object, that is the result of this method. If it throws a ClassNotFoundException, 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, a ClassNotFoundException is thrown.

Be aware that if a ClassLoader in the ClassLoaderRepository calls this method from its loadClass method, it exposes itself to a deadlock if another ClassLoader in the ClassLoaderRepository does the same thing at the same time. The loadClassBefore method is recommended to avoid the risk of deadlock.

Parameters

exclude:ClassLoader: The class loader to be excluded. May be null, in which case this method is equivalent to loadClass(className).
className:String: The name of the class to be loaded.

Returns:Class<?>

the loaded class.

Exceptions

ClassNotFoundException:: The specified class could not be found.

public Interface ClassLoaderRepository

Method Summary

Method Detail