edu.illinois.ncsa.datawolf.executor.java

Class DisposeClassLoader

java.lang.Object

java.lang.ClassLoader

java.security.SecureClassLoader

java.net.URLClassLoader

edu.illinois.ncsa.datawolf.executor.java.DisposeClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

public class DisposeClassLoader
extends URLClassLoader

Field Summary

Fields

Modifier and Type	Field and Description
protected File	loaderDir Path where resources loaded from JARs will be extracted.

Constructor Summary

Constructors

Constructor and Description
DisposeClassLoader()
DisposeClassLoader(ClassLoader parent)

Method Summary

Modifier and Type	Method and Description
void	addJarFile(File file)
static void	addTriggerPackage(String pkg)
protected void	clearReferences() Clear references.
void	dispose() Dispose the class loader.
protected boolean	filter(String name) Filter classes.
Class<?>	findClass(String name) Find the specified class in our local repositories, if possible.
protected Class<?>	findClassInternal(String name) Find specified class in local repositories.
protected Class<?>	findLoadedClass0(String name) Finds the class with the given name if it has previously been loaded and cached by this class loader, and return the Class object.
protected InputStream	findLoadedResource(String name) Finds the resource with the given name if it has previously been loaded and cached by this class loader, and return an input stream to the resource data.
URL	findResource(String name) Find the specified resource in our local repository, and return a URL refering to it, or null if this resource cannot be found.
protected ResourceEntry	findResourceInternal(String name, String path) Find specified resource in local repositories.
Enumeration<URL>	findResources(String name) Return an enumeration of URLs representing all of the resources with the given name.
URL	getResource(String name) Find the resource with the given name.
InputStream	getResourceAsStream(String name) Find the resource with the given name, and return an input stream that can be used for reading it.
protected URL	getURI(File file) Get URL.
protected URL	getURL(File file, boolean encoded) Get URL.
Class<?>	loadClass(String name) Load the class with the specified name.
Class<?>	loadClass(String name, boolean resolve) Load the class with the specified name, searching using the following algorithm until it finds and returns the class.
protected boolean	loadedByThisOrChild(Class<? extends Object> clazz) Determine whether a class was loaded by this class loader or one of its child class loaders.
protected void	nullInstance(Object instance)
void	setWorkDir(File workDir) Change the work directory.
protected boolean	validate(String name) Validate a classname.

Methods inherited from class java.net.URLClassLoader

addURL, close, definePackage, getPermissions, 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, findLibrary, findLoadedClass, findSystemClass, getClassLoadingLock, 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, toString, wait, wait, wait

Field Detail

loaderDir

protected File loaderDir

Path where resources loaded from JARs will be extracted.

Constructor Detail

DisposeClassLoader

public DisposeClassLoader()

DisposeClassLoader

public DisposeClassLoader(ClassLoader parent)

Method Detail

addTriggerPackage

public static void addTriggerPackage(String pkg)

addJarFile

public void addJarFile(File file)

setWorkDir

public void setWorkDir(File workDir)

Change the work directory.

dispose

public void dispose()

Dispose the class loader. This will try and remove any loaded classes from the cache. It will set all references in the classes loaded to null. It will also try and unload any drivers loaded in the DiverManager.

clearReferences

protected void clearReferences()

Clear references.

nullInstance

protected void nullInstance(Object instance)

loadedByThisOrChild

protected boolean loadedByThisOrChild(Class<? extends Object> clazz)

Determine whether a class was loaded by this class loader or one of its child class loaders.

getResource

public URL getResource(String name)

Find the resource with the given name. A resource is some data (images, audio, text, etc.) that can be accessed by class code in a way that is independent of the location of the code. The name of a resource is a "/"-separated path name that identifies the resource. If the resource cannot be found, return null.

This method searches according to the following algorithm, returning as soon as it finds the appropriate URL. If the resource cannot be found, returns null.

• If the delegate property is set to true, call the getResource() method of the parent class loader, if any.
• Call findResource() to find this resource in our locally defined repositories.
• Call the getResource() method of the parent class loader, if any.

Overrides:

getResource in class ClassLoader

Parameters:

name - Name of the resource to return a URL for

getResourceAsStream

public InputStream getResourceAsStream(String name)

Find the resource with the given name, and return an input stream that can be used for reading it. The search order is as described for getResource(), after checking to see if the resource data has been previously cached. If the resource cannot be found, return null.

Overrides:

getResourceAsStream in class URLClassLoader

Parameters:

name - Name of the resource to return an input stream for

findLoadedResource

protected InputStream findLoadedResource(String name)

Finds the resource with the given name if it has previously been loaded and cached by this class loader, and return an input stream to the resource data. If this resource has not been cached, return null.

Parameters:

name - Name of the resource to return

findResource

public URL findResource(String name)

Find the specified resource in our local repository, and return a URL refering to it, or null if this resource cannot be found.

Overrides:

findResource in class URLClassLoader

Parameters:

name - Name of the resource to be found

findResources

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

Return an enumeration of URLs representing all of the resources with the given name. If no resources with this name are found, return an empty set.

Overrides:

findResources in class URLClassLoader

Parameters:

name - Name of the resources to be found

Throws:

IOException - if an input/output error occurs

findResourceInternal

protected ResourceEntry findResourceInternal(String name,
                                             String path)

Find specified resource in local repositories.

Returns:

the loaded resource, or null if the resource isn't found

getURL

protected URL getURL(File file,
                     boolean encoded)
              throws MalformedURLException

Get URL.

Throws:

MalformedURLException

getURI

protected URL getURI(File file)
              throws MalformedURLException

Get URL.

Throws:

MalformedURLException

loadClass

public Class<?> loadClass(String name)
                   throws ClassNotFoundException

Load the class with the specified name. This method searches for classes in the same manner as loadClass(String, boolean) with false as the second argument.

Overrides:

loadClass in class ClassLoader

Parameters:

name - Name of the class to be loaded

Throws:

ClassNotFoundException - if the class was not found

loadClass

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

Load the class with the specified name, searching using the following algorithm until it finds and returns the class. If the class cannot be found, returns ClassNotFoundException.

• Call findLoadedClass(String) to check if the class has already been loaded. If it has, the same Class object is returned.
• If the delegate property is set to true, call the loadClass() method of the parent class loader, if any.
• Call findClass() to find this class in our locally defined repositories.
• Call the loadClass() method of our parent class loader, if any.

If the class was found using the above steps, and the resolve flag is true, this method will then call resolveClass(Class) on the resulting Class object.

Overrides:

loadClass in class ClassLoader

Parameters:

name - Name of the class to be loaded

resolve - If true then resolve the class

Throws:

ClassNotFoundException - if the class was not found

findLoadedClass0

protected Class<?> findLoadedClass0(String name)

Finds the class with the given name if it has previously been loaded and cached by this class loader, and return the Class object. If this class has not been cached, return null.

Parameters:

name - Name of the resource to return

findClass

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

Find the specified class in our local repositories, if possible. If not found, throw ClassNotFoundException.

Overrides:

findClass in class URLClassLoader

Parameters:

name - Name of the class to be loaded

Throws:

ClassNotFoundException - if the class was not found

findClassInternal

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

Find specified class in local repositories.

Returns:

the loaded class, or null if the class isn't found

Throws:

ClassNotFoundException

validate

protected boolean validate(String name)

Validate a classname. As per SRV.9.7.2, we must restict loading of classes from J2SE (java.*).

Parameters:

name - class name

Returns:

true if the name is valid

filter

protected boolean filter(String name)

Filter classes.

Parameters:

name - class name

Returns:

true if the class should be filtered