org.springframework.instrument.classloading.tomcat
Class TomcatInstrumentableClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.apache.catalina.loader.WebappClassLoader
                  org.springframework.instrument.classloading.tomcat.TomcatInstrumentableClassLoader

All Implemented Interfaces:

org.apache.catalina.Lifecycle, org.apache.catalina.loader.Reloader

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 Loader tag in Tomcat's Context definition in the server.xml file, with the Spring-provided "spring-tomcat-weaver.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.WebappClassLoader

org.apache.catalina.loader.WebappClassLoader.PrivilegedFindResource, org.apache.catalina.loader.WebappClassLoader.PrivilegedFindResourceByName, org.apache.catalina.loader.WebappClassLoader.PrivilegedGetClassLoader

Field Summary

private static java.lang.String	CLASS_SUFFIX
private WeavingTransformer	weavingTransformer Use an internal WeavingTransformer

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

allPermission, canonicalLoaderDir, delegate, ENABLE_CLEAR_REFERENCES, files, hasExternalRepositories, jarFiles, jarNames, jarPath, jarRealFiles, lastJarAccessed, lastModifiedDates, loaderDir, loaderPC, log, needConvert, notFoundResources, packageTriggers, parent, paths, permissionList, repositories, repositoryURLs, resourceEntries, resources, searchExternalFirst, securityManager, sm, started, system, triggers

Fields inherited from interface org.apache.catalina.Lifecycle

AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, DESTROY_EVENT, INIT_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

TomcatInstrumentableClassLoader()
Create a new TomcatInstrumentableClassLoader using the current context class loader.

TomcatInstrumentableClassLoader(java.lang.ClassLoader parent)
Create a new TomcatInstrumentableClassLoader with the supplied class loader as parent.

Method Summary

void	addTransformer(java.lang.instrument.ClassFileTransformer transformer) Delegate for LoadTimeWeaver's addTransformer method.
private static java.lang.Class	findCommonAncestor(java.lang.Class one, java.lang.Class two)
protected org.apache.catalina.loader.ResourceEntry	findResourceInternal(java.lang.String name, java.lang.String path)
java.lang.ClassLoader	getThrowawayClassLoader() Delegate for LoadTimeWeaver's getThrowawayClassLoader method.
private static void	shallowCopyFieldState(java.lang.Object src, java.lang.Object dest) Given the source object and the destination, which must be the same class or a subclass, copy all fields, including inherited fields.
java.lang.String	toString()

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

addLifecycleListener, addPermission, addPermission, addPermission, addRepository, addURL, clearReferences, closeJARs, deleteDir, filter, findClass, findClassInternal, findLifecycleListeners, findLoadedClass0, findLoadedResource, findRepositories, findResource, findResourceInternal, findResources, getAntiJARLocking, getClearReferencesHttpClientKeepAliveThread, getClearReferencesLogFactoryRelease, getClearReferencesStopThreads, getClearReferencesStopTimerThreads, getClearReferencesThreadLocals, getContextName, getDelegate, getJarPath, getPermissions, getResource, getResourceAsStream, getResources, getSearchExternalFirst, getURI, getURL, getURLs, isPackageSealed, isStarted, loadClass, loadClass, loadedByThisOrChild, modified, openJARs, refreshPolicy, removeLifecycleListener, setAntiJARLocking, setClearReferencesHttpClientKeepAliveThread, setClearReferencesLogFactoryRelease, setClearReferencesStopThreads, setClearReferencesStopTimerThreads, setClearReferencesThreadLocals, setDelegate, setJarPath, setParentClassLoader, setResources, setSearchExternalFirst, setWorkDir, start, stop, validate, validateJarFile

Methods inherited from class java.net.URLClassLoader

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, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Field Detail

CLASS_SUFFIX

private static final java.lang.String CLASS_SUFFIX

See Also:

Constant Field Values

weavingTransformer

private final WeavingTransformer weavingTransformer

Use an internal WeavingTransformer

Constructor Detail

TomcatInstrumentableClassLoader

public TomcatInstrumentableClassLoader()

Create a new TomcatInstrumentableClassLoader using the current context class loader.

See Also:

TomcatInstrumentableClassLoader(ClassLoader)

TomcatInstrumentableClassLoader

public TomcatInstrumentableClassLoader(java.lang.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(java.lang.instrument.ClassFileTransformer transformer)

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

See Also:

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

getThrowawayClassLoader

public java.lang.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(java.lang.String name,
                                                                        java.lang.String path)

Overrides:

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

toString

public java.lang.String toString()

Overrides:

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

shallowCopyFieldState

private static void shallowCopyFieldState(java.lang.Object src,
                                          java.lang.Object dest)
                                   throws java.lang.IllegalArgumentException

Given the source object and the destination, which must be the same class or a subclass, copy all fields, including inherited fields. Designed to work on objects with public no-arg constructors.

Throws:

java.lang.IllegalArgumentException - if arguments are incompatible or either is null

findCommonAncestor

private static java.lang.Class findCommonAncestor(java.lang.Class one,
                                                  java.lang.Class two)
                                           throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException