org.apache.catalina.loader
Class WebappLoader

java.lang.Object
  org.apache.catalina.util.LifecycleBase
      org.apache.catalina.util.LifecycleMBeanBase
          org.apache.catalina.loader.WebappLoader

All Implemented Interfaces:

PropertyChangeListener, EventListener, MBeanRegistration, Lifecycle, Loader

Direct Known Subclasses:

VirtualWebappLoader

public class WebappLoader
extends LifecycleMBeanBase
implements Loader, PropertyChangeListener

Classloader implementation which is specialized for handling web applications in the most efficient way, while being Catalina aware (all accesses to resources are made through the DirContext interface). This class loader supports detection of modified Java classes, which can be used to implement auto-reload support.

This class loader is configured by adding the pathnames of directories, JAR files, and ZIP files with the addRepository() method, prior to calling start(). When a new class is required, these repositories will be consulted first to locate the class. If it is not present, the system class loader will be used instead.

Version:

$Id: WebappLoader.java 1232850 2012-01-18 12:05:43Z markt $

Author:

Craig R. McClanahan, Remy Maucherat

Field Summary

protected static StringManager	sm The string manager for this package.
protected PropertyChangeSupport	support The property change support for this component.

Fields inherited from class org.apache.catalina.util.LifecycleMBeanBase

mserver

Fields inherited from interface org.apache.catalina.Lifecycle

AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

WebappLoader()
Construct a new WebappLoader with no defined parent class loader (so that the actual parent will be the system class loader).

WebappLoader(ClassLoader parent)
Construct a new WebappLoader with the specified class loader to be defined as the parent of the ClassLoader we ultimately create.

Method Summary

void	addPropertyChangeListener(PropertyChangeListener listener) Add a property change listener to this component.
void	addRepository(String repository) Add a new repository to the set of repositories for this class loader.
void	backgroundProcess() Execute a periodic task, such as reloading, etc.
void	closeJARs(boolean force) Used to periodically signal to the classloader to release JAR resources.
String[]	findRepositories() Return the set of repositories defined for this class loader.
ClassLoader	getClassLoader() Return the Java class loader to be used by this Container.
String	getClasspath() Classpath, as set in org.apache.catalina.jsp_classpath context property
Container	getContainer() Return the Container with which this Logger has been associated.
boolean	getDelegate() Return the "follow standard delegation model" flag used to configure our ClassLoader.
protected String	getDomainInternal() Method implemented by sub-classes to identify the domain in which MBeans should be registered.
String	getInfo() Return descriptive information about this Loader implementation and the corresponding version number, in the format <description>/<version>.
String	getLoaderClass() Return the ClassLoader class name.
String[]	getLoaderRepositories()
String	getLoaderRepositoriesString()
protected String	getObjectNameKeyProperties() Allow sub-classes to specify the key properties component of the ObjectName that will be used to register this component.
boolean	getReloadable() Return the reloadable flag for this Loader.
String[]	getRepositories()
String	getRepositoriesString() Extra repositories for this loader
boolean	getSearchExternalFirst()
boolean	modified() Has the internal repository associated with this Loader been modified, such that the loaded classes should be reloaded?
void	propertyChange(PropertyChangeEvent event) Process property change events from our associated Context.
void	removePropertyChangeListener(PropertyChangeListener listener) Remove a property change listener from this component.
void	setContainer(Container container) Set the Container with which this Logger has been associated.
void	setDelegate(boolean delegate) Set the "follow standard delegation model" flag used to configure our ClassLoader.
void	setLoaderClass(String loaderClass) Set the ClassLoader class name.
void	setReloadable(boolean reloadable) Set the reloadable flag for this Loader.
void	setSearchExternalFirst(boolean searchExternalFirst)
protected void	startInternal() Start associated ClassLoader and implement the requirements of LifecycleBase.startInternal().
protected void	stopInternal() Stop associated ClassLoader and implement the requirements of LifecycleBase.stopInternal().
String	toString() Return a String representation of this component.

Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase

destroyInternal, getDomain, getObjectName, initInternal, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister

Methods inherited from class org.apache.catalina.util.LifecycleBase

addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, init, removeLifecycleListener, setState, setState, start, stop

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

sm

protected static final StringManager sm

The string manager for this package.

support

protected PropertyChangeSupport support

The property change support for this component.

Constructor Detail

WebappLoader

public WebappLoader()

Construct a new WebappLoader with no defined parent class loader (so that the actual parent will be the system class loader).

WebappLoader

public WebappLoader(ClassLoader parent)

Construct a new WebappLoader with the specified class loader to be defined as the parent of the ClassLoader we ultimately create.

Parameters:

parent - The parent class loader

Method Detail

getClassLoader

public ClassLoader getClassLoader()

Return the Java class loader to be used by this Container.

Specified by:

getClassLoader in interface Loader

getContainer

public Container getContainer()

Return the Container with which this Logger has been associated.

Specified by:

getContainer in interface Loader

setContainer

public void setContainer(Container container)

Set the Container with which this Logger has been associated.

Specified by:

setContainer in interface Loader

Parameters:

container - The associated Container

getDelegate

public boolean getDelegate()

Return the "follow standard delegation model" flag used to configure our ClassLoader.

Specified by:

getDelegate in interface Loader

setDelegate

public void setDelegate(boolean delegate)

Set the "follow standard delegation model" flag used to configure our ClassLoader.

Specified by:

setDelegate in interface Loader

Parameters:

delegate - The new flag

getInfo

public String getInfo()

Return descriptive information about this Loader implementation and the corresponding version number, in the format <description>/<version>.

Specified by:

getInfo in interface Loader

getLoaderClass

public String getLoaderClass()

Return the ClassLoader class name.

setLoaderClass

public void setLoaderClass(String loaderClass)

Set the ClassLoader class name.

Parameters:

loaderClass - The new ClassLoader class name

getReloadable

public boolean getReloadable()

Return the reloadable flag for this Loader.

Specified by:

getReloadable in interface Loader

setReloadable

public void setReloadable(boolean reloadable)

Set the reloadable flag for this Loader.

Specified by:

setReloadable in interface Loader

Parameters:

reloadable - The new reloadable flag

getSearchExternalFirst

public boolean getSearchExternalFirst()

Returns:

Returns searchExternalFirst.

setSearchExternalFirst

public void setSearchExternalFirst(boolean searchExternalFirst)

Parameters:

searchExternalFirst - Whether external repositories should be searched first

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)

Add a property change listener to this component.

Specified by:

addPropertyChangeListener in interface Loader

Parameters:

listener - The listener to add

addRepository

public void addRepository(String repository)

Add a new repository to the set of repositories for this class loader.

Specified by:

addRepository in interface Loader

Parameters:

repository - Repository to be added

backgroundProcess

public void backgroundProcess()

Execute a periodic task, such as reloading, etc. This method will be invoked inside the classloading context of this container. Unexpected throwables will be caught and logged.

Specified by:

backgroundProcess in interface Loader

findRepositories

public String[] findRepositories()

Return the set of repositories defined for this class loader. If none are defined, a zero-length array is returned. For security reason, returns a clone of the Array (since String are immutable).

Specified by:

findRepositories in interface Loader

getRepositories

public String[] getRepositories()

getRepositoriesString

public String getRepositoriesString()

Extra repositories for this loader

getLoaderRepositories

public String[] getLoaderRepositories()

getLoaderRepositoriesString

public String getLoaderRepositoriesString()

getClasspath

public String getClasspath()

Classpath, as set in org.apache.catalina.jsp_classpath context property

Returns:

The classpath

modified

public boolean modified()

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

Specified by:

modified in interface Loader

closeJARs

public void closeJARs(boolean force)

Used to periodically signal to the classloader to release JAR resources.

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)

Remove a property change listener from this component.

Specified by:

removePropertyChangeListener in interface Loader

Parameters:

listener - The listener to remove

toString

public String toString()

Return a String representation of this component.

Overrides:

toString in class Object

startInternal

protected void startInternal()
                      throws LifecycleException

Start associated ClassLoader and implement the requirements of LifecycleBase.startInternal().

Specified by:

startInternal in class LifecycleBase

Throws:

LifecycleException - if this component detects a fatal error that prevents this component from being used

stopInternal

protected void stopInternal()
                     throws LifecycleException

Stop associated ClassLoader and implement the requirements of LifecycleBase.stopInternal().

Specified by:

stopInternal in class LifecycleBase

Throws:

LifecycleException - if this component detects a fatal error that prevents this component from being used

propertyChange

public void propertyChange(PropertyChangeEvent event)

Process property change events from our associated Context.

Specified by:

propertyChange in interface PropertyChangeListener

Parameters:

event - The property change event that has occurred

getDomainInternal

protected String getDomainInternal()

Description copied from class: LifecycleMBeanBase

Method implemented by sub-classes to identify the domain in which MBeans should be registered.

Specified by:

getDomainInternal in class LifecycleMBeanBase

Returns:

The name of the domain to use to register MBeans.

getObjectNameKeyProperties

protected String getObjectNameKeyProperties()

Description copied from class: LifecycleMBeanBase

Allow sub-classes to specify the key properties component of the ObjectName that will be used to register this component.

Specified by:

getObjectNameKeyProperties in class LifecycleMBeanBase

Returns:

The string representation of the key properties component of the desired ObjectName