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Loader (Catalina Internal API Documentation)

org.apache.catalina
Interface Loader

All Known Implementing Classes:
StandardLoader, WebappLoader

public interface Loader

A Loader represents a Java ClassLoader implementation that can be used by a Container to load class files (within a repository associated with the Loader) that are designed to be reloaded upon request, as well as a mechanism to detect whether changes have occurred in the underlying repository.

In order for a Loader implementation to successfully operate with a Context implementation that implements reloading, it must obey the following constraints:

  • Must implement Lifecycle so that the Context can indicate that a new class loader is required.
  • The start() method must unconditionally create a new ClassLoader implementation.
  • The stop() method must throw away its reference to the ClassLoader previously utilized, so that the class loader, all classes loaded by it, and all objects of those classes, can be garbage collected.
  • Must allow a call to stop() to be followed by a call to start() on the same Loader instance.
  • Based on a policy chosen by the implementation, must call the Context.reload() method on the owning Context when a change to one or more of the class files loaded by this class loader is detected.

Version:
$Revision: 1.5 $ $Date: 2001/07/22 20:13:30 $
Author:
Craig R. McClanahan

Method Summary
 void addPropertyChangeListener(java.beans.PropertyChangeListener listener)
          Add a property change listener to this component.
 void addRepository(java.lang.String repository)
          Add a new repository to the set of repositories for this class loader.
 java.lang.String[] findRepositories()
          Return the set of repositories defined for this class loader.
 java.lang.ClassLoader getClassLoader()
          Return the Java class loader to be used by this Container.
 Container getContainer()
          Return the Container with which this Loader has been associated.
 boolean getDelegate()
          Return the "follow standard delegation model" flag used to configure our ClassLoader.
 java.lang.String getInfo()
          Return descriptive information about this Loader implementation and the corresponding version number, in the format <description>/<version>.
 boolean getReloadable()
          Return the reloadable flag for this Loader.
 boolean modified()
          Has the internal repository associated with this Loader been modified, such that the loaded classes should be reloaded?
 void removePropertyChangeListener(java.beans.PropertyChangeListener listener)
          Remove a property change listener from this component.
 void setContainer(Container container)
          Set the Container with which this Loader has been associated.
 void setDelegate(boolean delegate)
          Set the "follow standard delegation model" flag used to configure our ClassLoader.
 void setReloadable(boolean reloadable)
          Set the reloadable flag for this Loader.
 

Method Detail

getClassLoader


public java.lang.ClassLoader getClassLoader()
Return the Java class loader to be used by this Container.


getContainer


public Container getContainer()
Return the Container with which this Loader has been associated.


setContainer


public void setContainer(Container container)
Set the Container with which this Loader has been associated.

Parameters:
container - The associated Container

getDelegate


public boolean getDelegate()
Return the "follow standard delegation model" flag used to configure our ClassLoader.


setDelegate


public void setDelegate(boolean delegate)
Set the "follow standard delegation model" flag used to configure our ClassLoader.

Parameters:
delegate - The new flag

getInfo


public java.lang.String getInfo()
Return descriptive information about this Loader implementation and the corresponding version number, in the format <description>/<version>.


getReloadable


public boolean getReloadable()
Return the reloadable flag for this Loader.


setReloadable


public void setReloadable(boolean reloadable)
Set the reloadable flag for this Loader.

Parameters:
reloadable - The new reloadable flag

addPropertyChangeListener


public void addPropertyChangeListener(java.beans.PropertyChangeListener listener)
Add a property change listener to this component.

Parameters:
listener - The listener to add

addRepository


public void addRepository(java.lang.String repository)
Add a new repository to the set of repositories for this class loader.

Parameters:
repository - Repository to be added

findRepositories


public java.lang.String[] findRepositories()
Return the set of repositories defined for this class loader. If none are defined, a zero-length array is returned.


modified


public boolean modified()
Has the internal repository associated with this Loader been modified, such that the loaded classes should be reloaded?


removePropertyChangeListener


public void removePropertyChangeListener(java.beans.PropertyChangeListener listener)
Remove a property change listener from this component.

Parameters:
listener - The listener to remove


Copyright 2000-2001 Apache Software Foundation. All Rights Reserved.