Package org.apache.catalina
Interface Loader
- All Known Implementing Classes:
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
Lifecycleso that the Context can indicate that a new class loader is required. - The
start()method must unconditionally create a newClassLoaderimplementation. - The
stop()method must throw away its reference to theClassLoaderpreviously 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 tostart()on the sameLoaderinstance. - Based on a policy chosen by the implementation, must call the
Context.reload()method on the owningContextwhen a change to one or more of the class files loaded by this class loader is detected.
- Author:
- Craig R. McClanahan
-
Method Summary
Modifier and TypeMethodDescriptionvoidAdd a property change listener to this component.voidExecute a periodic task, such as reloading, etc.booleanbooleanDeprecated.booleanmodified()Has the internal repository associated with this Loader been modified, such that the loaded classes should be reloaded?voidRemove a property change listener from this component.voidsetContext(Context context) Set the Context with which this Loader has been associated.voidsetDelegate(boolean delegate) Set the "follow standard delegation model" flag used to configure our ClassLoader.voidsetReloadable(boolean reloadable) Deprecated.
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Method Details
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backgroundProcess
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. -
getClassLoader
ClassLoader getClassLoader()- Returns:
- the Java class loader to be used by this Loader.
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getContext
Context getContext()- Returns:
- the Context with which this Loader has been associated.
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setContext
Set the Context with which this Loader has been associated.- Parameters:
context- The associated Context
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getDelegate
boolean getDelegate()- Returns:
- the "follow standard delegation model" flag used to configure our ClassLoader.
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setDelegate
void setDelegate(boolean delegate) Set the "follow standard delegation model" flag used to configure our ClassLoader.- Parameters:
delegate- The new flag
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getReloadable
Deprecated.UseContext.getReloadable(). This method will be removed in Tomcat 10.- Returns:
- the reloadable flag for this Loader.
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setReloadable
Deprecated.UseContext.setReloadable(boolean). This method will be removed in Tomcat 10.Set the reloadable flag for this Loader.- Parameters:
reloadable- The new reloadable flag
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addPropertyChangeListener
Add a property change listener to this component.- Parameters:
listener- The listener to add
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modified
boolean modified()Has the internal repository associated with this Loader been modified, such that the loaded classes should be reloaded?- Returns:
truewhen the repository has been modified,falseotherwise
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removePropertyChangeListener
Remove a property change listener from this component.- Parameters:
listener- The listener to remove
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Context.getReloadable().