WebappLoader (Apache Tomcat 8.0.53 API Documentation)

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

All Implemented Interfaces:

java.beans.PropertyChangeListener, java.util.EventListener, javax.management.MBeanRegistration, JmxEnabled, Lifecycle, Loader
```
public class WebappLoader
extends LifecycleMBeanBase
implements Loader, java.beans.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 WebResourceRoot). This class loader supports detection of modified Java classes, which can be used to implement auto-reload support.
This class loader is configured via the Resources children of its Context prior to calling start(). When a new class is required, these Resources will be consulted first to locate the class. If it is not present, the system class loader will be used instead.

Author:

Craig R. McClanahan, Remy Maucherat

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle
  Lifecycle.SingleUse

Field Summary

Fields
Modifier and Type	Field and Description
`protected static StringManager`	`sm` The string manager for this package.
`protected java.beans.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

Constructors
Constructor and Description
`WebappLoader()` Construct a new WebappLoader with no defined parent class loader (so that the actual parent will be the system class loader).
`WebappLoader(java.lang.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

Methods
Modifier and Type	Method and Description
`void`	`addPropertyChangeListener(java.beans.PropertyChangeListener listener)` Add a property change listener to this component.
`void`	`backgroundProcess()` Execute a periodic task, such as reloading, etc.
`java.lang.ClassLoader`	`getClassLoader()` Return the Java class loader to be used by this Container.
`java.lang.String`	`getClasspath()` Classpath, as set in org.apache.catalina.jsp_classpath context property
`Context`	`getContext()`
`boolean`	`getDelegate()` Return the "follow standard delegation model" flag used to configure our ClassLoader.
`protected java.lang.String`	`getDomainInternal()` Method implemented by sub-classes to identify the domain in which MBeans should be registered.
`java.lang.String`	`getLoaderClass()` Return the ClassLoader class name.
`java.lang.String[]`	`getLoaderRepositories()`
`java.lang.String`	`getLoaderRepositoriesString()`
`protected java.lang.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.
`boolean`	`modified()` Has the internal repository associated with this Loader been modified, such that the loaded classes should be reloaded?
`void`	`propertyChange(java.beans.PropertyChangeEvent event)` Process property change events from our associated Context.
`void`	`removePropertyChangeListener(java.beans.PropertyChangeListener listener)` Remove a property change listener from this component.
`void`	`setContext(Context context)` Set the Context with which this Loader has been associated.
`void`	`setDelegate(boolean delegate)` Set the "follow standard delegation model" flag used to configure our ClassLoader.
`void`	`setLoaderClass(java.lang.String loaderClass)` Set the ClassLoader class name.
`void`	`setReloadable(boolean reloadable)` Set the reloadable flag for this Loader.
`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()`.
`java.lang.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 final java.beans.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(java.lang.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 java.lang.ClassLoader getClassLoader()
```
    Return the Java class loader to be used by this Container.
    
    Specified by:
    
    getClassLoader in interface Loader
    
    Returns:
    the Java class loader to be used by this Container.
  - getContext
```
public Context getContext()
```
    Specified by:
    
    getContext in interface Loader
    
    Returns:
    the Context with which this Loader has been associated.
  - setContext
```
public void setContext(Context context)
```
    Description copied from interface: Loader
    
    Set the Context with which this Loader has been associated.
    
    Specified by:
    
    setContext in interface Loader
    
    Parameters:
    context - The associated Context
  - getDelegate
```
public boolean getDelegate()
```
    Return the "follow standard delegation model" flag used to configure our ClassLoader.
    
    Specified by:
    
    getDelegate in interface Loader
    
    Returns:
    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.
    
    Specified by:
    
    setDelegate in interface Loader
    
    Parameters:
    delegate - The new flag
  - getLoaderClass
```
public java.lang.String getLoaderClass()
```
    Return the ClassLoader class name.
  - setLoaderClass
```
public void setLoaderClass(java.lang.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
    
    Returns:
    the reloadable flag for this 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
  - addPropertyChangeListener
```
public void addPropertyChangeListener(java.beans.PropertyChangeListener listener)
```
    Add a property change listener to this component.
    
    Specified by:
    
    addPropertyChangeListener in interface Loader
    
    Parameters:
    listener - The listener to add
  - 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
  - getLoaderRepositories
```
public java.lang.String[] getLoaderRepositories()
```
  - getLoaderRepositoriesString
```
public java.lang.String getLoaderRepositoriesString()
```
  - getClasspath
```
public java.lang.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
    
    Returns:
    true when the repository has been modified, false otherwise
  - removePropertyChangeListener
```
public void removePropertyChangeListener(java.beans.PropertyChangeListener listener)
```
    Remove a property change listener from this component.
    
    Specified by:
    
    removePropertyChangeListener in interface Loader
    
    Parameters:
    listener - The listener to remove
  - toString
```
public java.lang.String toString()
```
    Return a String representation of this component.
    
    Overrides:
    
    toString in class java.lang.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(java.beans.PropertyChangeEvent event)
```
    Process property change events from our associated Context.
    
    Specified by:
    
    propertyChange in interface java.beans.PropertyChangeListener
    
    Parameters:
    event - The property change event that has occurred
  - getDomainInternal
```
protected java.lang.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 java.lang.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

Class WebappLoader

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle

Field Summary

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

Fields inherited from interface org.apache.catalina.Lifecycle

Constructor Summary

Method Summary

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

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

Methods inherited from class java.lang.Object

Field Detail

sm

support

Constructor Detail

WebappLoader

WebappLoader

Method Detail

getClassLoader

getContext

setContext

getDelegate

setDelegate

getLoaderClass

setLoaderClass

getReloadable

setReloadable

addPropertyChangeListener

backgroundProcess

getLoaderRepositories

getLoaderRepositoriesString

getClasspath

modified

removePropertyChangeListener

toString

startInternal

stopInternal

propertyChange

getDomainInternal

getObjectNameKeyProperties