org.jppf.classloader
Class AbstractJPPFClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              org.jppf.classloader.AbstractJPPFClassLoaderLifeCycle
                  org.jppf.classloader.AbstractJPPFClassLoader

Direct Known Subclasses:

JPPFClassLoader, JPPFLocalClassLoader

public abstract class AbstractJPPFClassLoader
extends AbstractJPPFClassLoaderLifeCycle

This class is a custom class loader serving the purpose of dynamically loading the JPPF classes and the client application classes, to avoid costly redeployment system-wide.

Author:

Laurent Cohen

Nested Class Summary

Nested classes/interfaces inherited from class org.jppf.classloader.AbstractJPPFClassLoaderLifeCycle

AbstractJPPFClassLoaderLifeCycle.AbstractResourceRequest

Field Summary

Fields inherited from class org.jppf.classloader.AbstractJPPFClassLoaderLifeCycle

cache, dynamic, executor, INITIALIZING, LOCK, requestUuid, serializer, uuidPath

Constructor Summary

AbstractJPPFClassLoader(ClassLoader parent)
Initialize this class loader with a parent class loader.

AbstractJPPFClassLoader(ClassLoader parent, List<String> uuidPath)
Initialize this class loader with a parent class loader.

Method Summary

byte[]	computeRemoteData(byte[] callable) Request the remote computation of a JPPFCallable on the client.
Class<?>	findClass(String name) Find a class in this class loader's classpath.
protected URL[]	findMultipleResources(String... names) Get multiple reources, specified by their names, from the classpath.
URL	findResource(String name) Finds the resource with the specified name.
Enumeration<URL>	findResources(String name) Find all resources with the specified name.
URL[]	getMultipleResources(String... names) Get multiple reources, specified by their names, from the classpath.
InputStream	getResourceAsStream(String name) Get a stream from a resource file accessible form this class loader.
Class<?>	loadJPPFClass(String name) Load a JPPF class from the server.

Methods inherited from class org.jppf.classloader.AbstractJPPFClassLoaderLifeCycle

addURL, close, getSerializer, init, loadRemoteData, loadResourceData, loadResourceData0, reset, setRequestUuid

Methods inherited from class java.net.URLClassLoader

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, getPackage, getPackages, getParent, getResource, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractJPPFClassLoader

public AbstractJPPFClassLoader(ClassLoader parent)

Initialize this class loader with a parent class loader.

Parameters:

parent - a ClassLoader instance.

AbstractJPPFClassLoader

public AbstractJPPFClassLoader(ClassLoader parent,
                               List<String> uuidPath)

Initialize this class loader with a parent class loader.

Parameters:

parent - a ClassLoader instance.

uuidPath - unique identifier for the submitting application.

Method Detail

loadJPPFClass

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

Load a JPPF class from the server.

Parameters:

name - the binary name of the class

Returns:

the resulting Class object

Throws:

ClassNotFoundException - if the class could not be found

findClass

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

Find a class in this class loader's classpath.

Overrides:

findClass in class URLClassLoader

Parameters:

name - binary name of the resource to find.

Returns:

a defined Class instance.

Throws:

ClassNotFoundException - if the class could not be loaded.

See Also:

ClassLoader.findClass(java.lang.String)

computeRemoteData

public byte[] computeRemoteData(byte[] callable)
                         throws Exception

Request the remote computation of a JPPFCallable on the client.

Parameters:

callable - the serialized callable to execute remotely.

Returns:

an array of bytes containing the result of the callable's execution.

Throws:

Exception - if the connection was lost and could not be reestablished.

findResource

public URL findResource(String name)

Finds the resource with the specified name. The resource lookup order is the same as the one specified by getResourceAsStream(String)

Overrides:

findResource in class URLClassLoader

Parameters:

name - the name of the resource to find.

Returns:

the URL of the resource.

See Also:

ClassLoader.findResource(java.lang.String)

getResourceAsStream

public InputStream getResourceAsStream(String name)

Get a stream from a resource file accessible form this class loader. The lookup order is defined as follows:

• locally, in the classpath for this class loader, such as specified by ClassLoader.getResourceAsStream(String)
  
• if the parent of this class loader is NOT an instance of AbstractJPPFClassLoader, in the classpath of the JPPF driver, such as specified by ResourceProvider.getResourceAsBytes(String, ClassLoader)
(the search may eventually be sped up by looking up the driver's resource cache first)
• if the parent of this class loader IS an instance of AbstractJPPFClassLoader, in the classpath of the JPPF client, such as specified by ResourceProvider.getResourceAsBytes(String, ClassLoader) (the search may eventually be sped up by looking up the driver's resource cache first)

Overrides:

getResourceAsStream in class ClassLoader

Parameters:

name - name of the resource to obtain a stream from.

Returns:

an InputStream instance, or null if the resource was not found.

See Also:

ClassLoader.getResourceAsStream(java.lang.String)

findResources

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

Find all resources with the specified name.

Overrides:

findResources in class URLClassLoader

Parameters:

name - name of the resources to find in the clas loader's classpath.

Returns:

An enumeration of URLs pointing to the resources found.

Throws:

IOException - if an error occurs.

See Also:

ClassLoader.findResources(java.lang.String)

findMultipleResources

protected URL[] findMultipleResources(String... names)

Get multiple reources, specified by their names, from the classpath. This method functions like #getResource(String), except that it look up and returns multiple URLs.

Parameters:

names - the names of te resources to find.

Returns:

an array of URLs, one for each looked up resources. Some URLs may be null, however the returned array is never null, and results are in the same order as the specified resource names.

getMultipleResources

public URL[] getMultipleResources(String... names)

Get multiple reources, specified by their names, from the classpath. This method functions like #getResource(String), except that it looks up and returns multiple URLs.

Parameters:

names - the names of te resources to find.

Returns:

an array of URLs, one for each looked up resources. Some URLs may be null, however the returned array is never null, and results are in the same order as the specified resource names.