danbikel.util
Class JarClassLoader

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              danbikel.util.JarClassLoader

public class JarClassLoader
extends URLClassLoader

A class loader for loading a jar file from any URL. Modified from a version taken from Sun's Java website (The JarClassLoader Class).

Constructor Summary

JarClassLoader(URL url)
Creates a new JarClassLoader for the specified URL.

JarClassLoader(URL url, ClassLoader parent)
Creates a new JarClassLoader for the specified URL and parent class loader.

Method Summary

String	getMainClassName() Returns the name of the jar file main class, or null if no "Main-Class" manifest attributes was defined.
void	invokeClass(String name, String[] args) Invokes the application in this jar file given the name of the main class and an array of arguments.

Methods inherited from class java.net.URLClassLoader

addURL, definePackage, findClass, findResource, findResources, 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, getResourceAsStream, 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

JarClassLoader

public JarClassLoader(URL url)

Creates a new JarClassLoader for the specified URL.

Parameters:

url - the url of the jar file

JarClassLoader

public JarClassLoader(URL url,
                      ClassLoader parent)

Creates a new JarClassLoader for the specified URL and parent class loader.

Parameters:

url - the url of the jar file

parent - the parent class loader for delegation

Method Detail

getMainClassName

public String getMainClassName()
                        throws IOException

Returns the name of the jar file main class, or null if no "Main-Class" manifest attributes was defined.

Throws:

IOException

invokeClass

public void invokeClass(String name,
                        String[] args)
                 throws ClassNotFoundException,
                        NoSuchMethodException,
                        InvocationTargetException

Invokes the application in this jar file given the name of the main class and an array of arguments. The class must define a static method "main" which takes an array of String arguemtns and is of return type "void".

Parameters:

name - the name of the main class

args - the arguments for the application

Throws:

ClassNotFoundException - if the specified class could not be found

NoSuchMethodException - if the specified class does not contain a "main" method

InvocationTargetException - if the application raised an exception