freenet.support

Class JarClassLoader

java.lang.Object

java.lang.ClassLoader

freenet.support.JarClassLoader

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class JarClassLoader
extends java.lang.ClassLoader
implements java.io.Closeable

Class loader that loads classes from a JAR file. The JAR file gets copied to a temporary location; requests for classes and resources from this class loader are then satisfied from this local copy.

Constructor Summary

Constructors

Constructor and Description
JarClassLoader(java.io.File file) Constructs a new jar class loader that loads classes from the specified file.
JarClassLoader(java.lang.String fileName) Constructs a new jar class loader that loads classes from the jar file with the given name in the local file system.
JarClassLoader(java.net.URL fileUrl, long length) Constructs a new jar class loader that loads classes from the specified URL.

Method Summary

Modifier and Type	Method and Description
void	close()
protected java.lang.Package	definePackage(java.lang.String name)
protected java.lang.Package	definePackage(java.lang.String name, java.util.jar.Manifest man)
protected java.lang.Class<?>	findClass(java.lang.String name)
protected java.net.URL	findResource(java.lang.String name)
java.io.InputStream	getResourceAsStream(java.lang.String name)

Methods inherited from class java.lang.ClassLoader

clearAssertionStatus, defineClass, defineClass, defineClass, defineClass, definePackage, findLibrary, findLoadedClass, findResources, findSystemClass, getClassLoadingLock, getPackage, getPackages, getParent, getResource, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, loadClass, loadClass, registerAsParallelCapable, 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

JarClassLoader

public JarClassLoader(java.lang.String fileName)
               throws java.io.IOException

Constructs a new jar class loader that loads classes from the jar file with the given name in the local file system.

Parameters:

fileName - The name of the jar file

Throws:

java.io.IOException - if an I/O error occurs

JarClassLoader

public JarClassLoader(java.net.URL fileUrl,
                      long length)
               throws java.io.IOException

Constructs a new jar class loader that loads classes from the specified URL.

Parameters:

fileUrl - The URL to load the jar file from

length - The length of the jar file if known, -1 otherwise

Throws:

java.io.IOException - if an I/O error occurs

JarClassLoader

public JarClassLoader(java.io.File file)
               throws java.io.IOException

Constructs a new jar class loader that loads classes from the specified file.

Parameters:

file - The file to load classes from

Throws:

java.io.IOException - if an I/O error occurs

Method Detail

findClass

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

This method searches the temporary copy of the jar file for an entry that is specified by the given class name.

Overrides:

findClass in class java.lang.ClassLoader

Throws:

java.lang.ClassNotFoundException

See Also:

ClassLoader.findClass(java.lang.String)

findResource

protected java.net.URL findResource(java.lang.String name)

Finds the resource within this jar only. If it isn't found within the jar, getResourceAsStream() will look elsewhere.

Overrides:

findResource in class java.lang.ClassLoader

getResourceAsStream

public java.io.InputStream getResourceAsStream(java.lang.String name)

If the resource is found in this jar, opens the stream using ZipEntry's, so when tempJarFile is closed, so are all the streams, hence we can delete the jar on Windows.

Overrides:

getResourceAsStream in class java.lang.ClassLoader

See Also:

ClassLoader.getResourceAsStream(java.lang.String)

definePackage

protected java.lang.Package definePackage(java.lang.String name)
                                   throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

definePackage

protected java.lang.Package definePackage(java.lang.String name,
                                          java.util.jar.Manifest man)
                                   throws java.lang.IllegalArgumentException

Throws:

java.lang.IllegalArgumentException

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException