Package com.sun.istack.tools

Class ParallelWorldClassLoader

java.lang.Object

java.lang.ClassLoader

com.sun.istack.tools.ParallelWorldClassLoader

All Implemented Interfaces:

Closeable, AutoCloseable

public class ParallelWorldClassLoader
extends ClassLoader
implements Closeable

Load classes/resources from a side folder, so that classes of the same package can live in a single jar file.

For example, with the following jar file:

  /
  +- foo
     +- X.class
  +- bar
     +- X.class
 

ParallelWorldClassLoader("foo/") would load X.class from /foo/X.class (note that X is defined in the root package, not foo.X.

This can be combined with MaskingClassLoader to mask classes which are loaded by the parent class loader so that the child class loader classes living in different folders are loaded before the parent class loader loads classes living the jar file publicly visible For example, with the following jar file:

  /
  +- foo
     +- X.class
  +- bar
     +-foo
        +- X.class
 

ParallelWorldClassLoader(MaskingClassLoader.class.getClassLoader()) would load foo.X.class from /bar/foo.X.class not the foo.X.class in the publicly visible place in the jar file, thus masking the parent classLoader from loading the class from foo.X.class (note that X is defined in the package foo, not bar.foo.X.

Author:

Kohsuke Kawaguchi

Constructor Summary

Constructors

Constructor	Description
ParallelWorldClassLoader(ClassLoader parent, String prefix)

Method Summary

Modifier and Type	Method	Description
void	close()
protected Class	findClass(String name)
protected URL	findResource(String name)
protected Enumeration<URL>	findResources(String name)
static URL	toJarUrl(URL res)	Given the URL inside jar, returns the URL to the jar itself.

Methods inherited from class java.lang.ClassLoader

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

Methods inherited from class java.lang.Object

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

Constructor Details

ParallelWorldClassLoader

public ParallelWorldClassLoader(ClassLoader parent,
 String prefix)

Method Details

findClass

protected Class findClass(String name)
                   throws ClassNotFoundException

Overrides:

findClass in class ClassLoader

Throws:

ClassNotFoundException

findResource

protected URL findResource(String name)

Overrides:

findResource in class ClassLoader

findResources

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

Overrides:

findResources in class ClassLoader

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException

toJarUrl

public static URL toJarUrl(URL res)
                    throws ClassNotFoundException,
MalformedURLException

Given the URL inside jar, returns the URL to the jar itself.

Parameters:

res - Resource in a jar

Returns:

URL to the conaining jar file

Throws:

ClassNotFoundException - if res does not denote jar URL

MalformedURLException - if computed URL is invalid