org.springframework.instrument.classloading.tomcat

Class TomcatInstrumentableClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.apache.catalina.loader.WebappClassLoaderBase

org.apache.catalina.loader.WebappClassLoader

org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.catalina.Lifecycle, org.apache.juli.WebappProperties, org.apache.tomcat.InstrumentableClassLoader

public class TomcatInstrumentableClassLoader
extends org.apache.catalina.loader.WebappClassLoader

Extension of Tomcat's default class loader which adds instrumentation to loaded classes without the need to use a VM-wide agent.

To be registered using a <a href="http://tomcat.apache.org/tomcat-5.5-doc/config/loader.html">Loader</a> tag in Tomcat's <a href="http://tomcat.apache.org/tomcat-5.5-doc/config/context.html">Context</a> definition in the server.xml file, with the Spring-provided "spring-instrument-tomcat.jar" file deployed into Tomcat's "server/lib" (for Tomcat 5.x) or "lib" (for Tomcat 6.x) directory. The required configuration tag looks as follows:

<Loader loaderClass="org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader"/>

Typically used in combination with a ReflectiveLoadTimeWeaver defined in the Spring application context. The addTransformer and getThrowawayClassLoader methods mirror the corresponding methods in the LoadTimeWeaver interface, as expected by ReflectiveLoadTimeWeaver.

See the PetClinic sample application for a full example of this ClassLoader in action.

NOTE: Requires Apache Tomcat version 5.0 or higher.

Since:

2.0

Author:

Costin Leau, Juergen Hoeller

See Also:

addTransformer(java.lang.instrument.ClassFileTransformer), getThrowawayClassLoader(), ReflectiveLoadTimeWeaver

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.catalina.loader.WebappClassLoaderBase

org.apache.catalina.loader.WebappClassLoaderBase.PrivilegedFindResourceByName, org.apache.catalina.loader.WebappClassLoaderBase.PrivilegedGetClassLoader

Field Summary

Fields inherited from class org.apache.catalina.loader.WebappClassLoaderBase

allPermission, delegate, loaderPC, needConvert, packageTriggersDeny, packageTriggersPermit, parent, permissionList, resourceEntries, resources, securityManager, sm

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
TomcatInstrumentableClassLoader() Create a new TomcatInstrumentableClassLoader using the current context class loader.
TomcatInstrumentableClassLoader(ClassLoader parent) Create a new TomcatInstrumentableClassLoader with the supplied class loader as parent.

Method Summary

Modifier and Type	Method and Description
void	addTransformer(ClassFileTransformer transformer) Delegate for LoadTimeWeaver's addTransformer method.
protected org.apache.catalina.loader.ResourceEntry	findResourceInternal(String name, String path, boolean manifestRequired)
ClassLoader	getThrowawayClassLoader() Delegate for LoadTimeWeaver's getThrowawayClassLoader method.
String	toString()

Methods inherited from class org.apache.catalina.loader.WebappClassLoader

copyWithoutTransformers, getClassLoadingLock

Methods inherited from class org.apache.catalina.loader.WebappClassLoaderBase

addLifecycleListener, addURL, checkStateForClassLoading, checkStateForResourceLoading, clearReferences, copyStateWithoutTransformers, destroy, doDefineClass, filter, findClass, findClassInternal, findLifecycleListeners, findLoadedClass0, findLoadedResource, findResource, findResources, getClearReferencesHttpClientKeepAliveThread, getClearReferencesLogFactoryRelease, getClearReferencesStatic, getClearReferencesStopThreads, getClearReferencesStopTimerThreads, getContextName, getDelegate, getHostName, getJavaseClassLoader, getPermissions, getResource, getResourceAsStream, getResources, getServiceName, getState, getStateName, getURLs, getWebappName, init, isPackageSealed, loadClass, loadClass, modified, refreshPolicy, removeLifecycleListener, removeTransformer, setClearReferencesHttpClientKeepAliveThread, setClearReferencesLogFactoryRelease, setClearReferencesStatic, setClearReferencesStopThreads, setClearReferencesStopTimerThreads, setDelegate, setJavaseClassLoader, setResources, start, stop, validate

Methods inherited from class java.net.URLClassLoader

close, definePackage, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findSystemClass, getPackage, getPackages, getParent, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, registerAsParallelCapable, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Constructor Detail

TomcatInstrumentableClassLoader

public TomcatInstrumentableClassLoader()

Create a new TomcatInstrumentableClassLoader using the current context class loader.

See Also:

TomcatInstrumentableClassLoader(ClassLoader)

TomcatInstrumentableClassLoader

public TomcatInstrumentableClassLoader(ClassLoader parent)

Create a new TomcatInstrumentableClassLoader with the supplied class loader as parent.

Parameters:

parent - the parent ClassLoader to be used

Method Detail

addTransformer

public void addTransformer(ClassFileTransformer transformer)

Delegate for LoadTimeWeaver's addTransformer method. Typically called through ReflectiveLoadTimeWeaver.

Specified by:

addTransformer in interface org.apache.tomcat.InstrumentableClassLoader

Overrides:

addTransformer in class org.apache.catalina.loader.WebappClassLoaderBase

See Also:

LoadTimeWeaver.addTransformer(java.lang.instrument.ClassFileTransformer), ReflectiveLoadTimeWeaver

getThrowawayClassLoader

public ClassLoader getThrowawayClassLoader()

Delegate for LoadTimeWeaver's getThrowawayClassLoader method. Typically called through ReflectiveLoadTimeWeaver.

See Also:

LoadTimeWeaver.getThrowawayClassLoader(), ReflectiveLoadTimeWeaver

findResourceInternal

protected org.apache.catalina.loader.ResourceEntry findResourceInternal(String name,
                                                                        String path,
                                                                        boolean manifestRequired)

Overrides:

findResourceInternal in class org.apache.catalina.loader.WebappClassLoaderBase

toString

public String toString()

Overrides:

toString in class org.apache.catalina.loader.WebappClassLoaderBase