Module org.eclipse.jetty.ee.webapp

Package org.eclipse.jetty.ee.webapp

Class WebAppClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

org.eclipse.jetty.ee.webapp.WebAppClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable, org.eclipse.jetty.util.ClassVisibilityChecker

Direct Known Subclasses:

CachingWebAppClassLoader

@ManagedObject
public class WebAppClassLoader
extends URLClassLoader
implements org.eclipse.jetty.util.ClassVisibilityChecker

ClassLoader for Http Context.

Specializes URLClassLoader with some utility and file mapping methods.

This loader implements the Servlet specification behavior that may invert the normal Java classloader parent priority behaviour. The ClassVisibilityChecker API of the WebAppClassLoader.Context implementation is used to determine which classes from the parent classloader are hidden from the context, and which are protected from being overridden by the context.

Java compliant loading, where the parent loader always has priority, can be selected with the WebAppClassLoader.Context.isParentLoaderPriority() method.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	WebAppClassLoader.Context	The Context in which the classloader operates.

Constructor Summary

Constructors

Constructor	Description
WebAppClassLoader(ClassLoader parent, WebAppClassLoader.Context context)	Constructor.
WebAppClassLoader(WebAppClassLoader.Context context)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	addClassPath(String classPathList)
void	addClassPath(org.eclipse.jetty.util.resource.Resource resource)
void	addJars(org.eclipse.jetty.util.resource.Resource libs)	Add elements to the class path for the context from the jar and zip files found in the specified resource.
void	addTransformer(ClassFileTransformer transformer)
void	close()
protected Class<?>	findClass(String name)
protected Class<?>	foundClass(String name, URL url)
WebAppClassLoader.Context	getContext()
String	getName()	Get the name of the classloader.
PermissionCollection	getPermissions(CodeSource cs)
URL	getResource(String name)	Get a resource from the classloader
Enumeration<URL>	getResources(String name)
boolean	isHiddenClass(Class<?> clazz)
boolean	isProtectedClass(Class<?> clazz)
protected Class<?>	loadAsResource(String name, boolean checkSystemResource)	Look for the classname as a resource to avoid loading a class that is potentially a system resource.
protected Class<?>	loadClass(String name, boolean resolve)
boolean	removeTransformer(ClassFileTransformer transformer)
static <T> T	runWithHiddenClassAccess(PrivilegedExceptionAction<T> action)	Run an action with access to Hidden Classes
void	setName(String name)	Set the name of the classloader.
String	toString()

Methods inherited from class java.net.URLClassLoader

addURL, definePackage, findResource, findResources, getResourceAsStream, getURLs, newInstance, newInstance

Methods inherited from class java.security.SecureClassLoader

defineClass, defineClass

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findClass, findLibrary, findLoadedClass, findResource, findSystemClass, getClassLoadingLock, getDefinedPackage, getDefinedPackages, getPackage, getPackages, getParent, getPlatformClassLoader, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, getUnnamedModule, isRegisteredAsParallelCapable, loadClass, registerAsParallelCapable, resolveClass, resources, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.jetty.util.ClassVisibilityChecker

isServerClass, isSystemClass

Constructor Details

WebAppClassLoader

public WebAppClassLoader(WebAppClassLoader.Context context)

Constructor.

The Thread.currentThread() Thread.getContextClassLoader() will be used as the parent loader, unless null, in which case the classloader that loaded this class is used as the parent.

Parameters:

context - the context for this classloader

WebAppClassLoader

public WebAppClassLoader(ClassLoader parent,
 WebAppClassLoader.Context context)

Constructor.

Parameters:

parent - the parent classloader; if null then the Thread.currentThread() Thread.getContextClassLoader() will be used as the parent loader, unless also null, in which case the classloader that loaded this class is used as the parent.

context - the context for this classloader

Method Details

runWithHiddenClassAccess

public static <T> T runWithHiddenClassAccess(PrivilegedExceptionAction<T> action)
                                      throws Exception

Run an action with access to Hidden Classes

Run the passed PrivilegedExceptionAction with the classloader configured so as to allow server classes to be visible

Type Parameters:

T - the type of PrivilegedExceptionAction and the type returned by the action

Parameters:

action - The action to run

Returns:

The return from the action

Throws:

Exception - if thrown by the action

getName

public String getName()

Get the name of the classloader.

Overrides:

getName in class ClassLoader

Returns:

the name of the classloader

setName

public void setName(String name)

Set the name of the classloader.

Parameters:

name - the name of the classloader

getContext

public WebAppClassLoader.Context getContext()

addClassPath

public void addClassPath(org.eclipse.jetty.util.resource.Resource resource)

Parameters:

resource - The resources to add to the classpath

addClassPath

public void addClassPath(String classPathList)
                  throws IOException

Parameters:

classPathList - Comma or semicolon separated path of filenames or URLs pointing to directories or jar files. Directories should end with '/'.

Throws:

IOException - if unable to add classpath

addJars

public void addJars(org.eclipse.jetty.util.resource.Resource libs)

Add elements to the class path for the context from the jar and zip files found in the specified resource.

Parameters:

libs - the directory resource that contains the jar and/or zip files.

getPermissions

public PermissionCollection getPermissions(CodeSource cs)

Overrides:

getPermissions in class URLClassLoader

getResources

public Enumeration<URL> getResources(String name)
                              throws IOException

Overrides:

getResources in class ClassLoader

Throws:

IOException

getResource

public URL getResource(String name)

Get a resource from the classloader

NOTE: this method provides a convenience of hacking off a leading / should one be present. This is non-standard and it is recommended to not rely on this behavior

Overrides:

getResource in class ClassLoader

loadClass

protected Class<?> loadClass(String name,
 boolean resolve)
                      throws ClassNotFoundException

Overrides:

loadClass in class ClassLoader

Throws:

ClassNotFoundException

addTransformer

public void addTransformer(ClassFileTransformer transformer)

removeTransformer

public boolean removeTransformer(ClassFileTransformer transformer)

loadAsResource

protected Class<?> loadAsResource(String name,
 boolean checkSystemResource)
                           throws ClassNotFoundException

Look for the classname as a resource to avoid loading a class that is potentially a system resource.

Parameters:

name - the name of the class to load

checkSystemResource - if true and the class isn't a system class we return it

Returns:

the loaded class

Throws:

ClassNotFoundException - if the class cannot be found

findClass

protected Class<?> findClass(String name)
                      throws ClassNotFoundException

Overrides:

findClass in class URLClassLoader

Throws:

ClassNotFoundException

foundClass

protected Class<?> foundClass(String name,
 URL url)
                       throws ClassNotFoundException

Throws:

ClassNotFoundException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class URLClassLoader

Throws:

IOException

toString

public String toString()

Overrides:

toString in class Object

isProtectedClass

public boolean isProtectedClass(Class<?> clazz)

Specified by:

isProtectedClass in interface org.eclipse.jetty.util.ClassVisibilityChecker

isHiddenClass

public boolean isHiddenClass(Class<?> clazz)

Specified by:

isHiddenClass in interface org.eclipse.jetty.util.ClassVisibilityChecker