net.yagga.util
Class BootstrapJarClassLoader

java.lang.Object
  |
  +--java.lang.ClassLoader
        |
        +--net.yagga.util.BootstrapJarClassLoader

public class BootstrapJarClassLoader

extends java.lang.ClassLoader

A META class loader for loading jar files. interesting the class can load jar classes from different JARs and from the same jar (if this class is jarred with other jars...
This class is a collection of methods and features found in class MetaJarClassLoader, MetaJarResource, JarClassLoader and MetaUt. THey are reduced and compacted here for convenience.

Author:

Walter Gamba

See Also:

MetaJarResource, JarClassLoader, MetaUt, MetaJarClassLoader

Inner classes inherited from class java.lang.ClassLoader

java.lang.ClassLoader.NativeLibrary

Field Summary

private boolean	executingFromJar
private java.util.Hashtable	htSizes
private java.lang.String	jarFile
private java.lang.String	jarJarFile
private java.util.Hashtable	metaJarContent
private java.util.jar.Manifest	metaManifest

Fields inherited from class java.lang.ClassLoader

bootstrapClassPath, classes, defaultDomain, defaultPermissions, domains, getClassLoaderPerm, initialized, loadedLibraryNames, nativeLibraries, nativeLibraryContext, nocerts, package2certs, packages, parent, scl, sclSet, sys_paths, systemNativeLibraries, usr_paths

Constructor Summary

BootstrapJarClassLoader(java.lang.String jFile)
constructor: decides if the jar filename passed belongs to a jar that: a) is outside the current class/jar file b) is inside the JAR file where this class is also stored.

Method Summary

protected java.lang.Class	findClass(java.lang.String className) method taht actually reads the class from raw bytes
java.lang.String	getActualJarName() Legge l'attributo actualJarName dell object BootstrapJarClassLoader
java.lang.String	getMainClassName() Returns the name of the jar file main class, or null if no "Main-Class" manifest attributes was defined.
private java.util.jar.JarInputStream	getTopJIS() get top level JAR input stream
private void	initTopJarSizes() read sizes fror top-level JAR file.
void	invokeClass(java.lang.String name, java.lang.String[] args) Invokes the application in this jar file given the name of the main class and an array of arguments.
static void	main(java.lang.String[] argv) Descrizione del metodo
private java.io.InputStream	openResource(java.lang.String filename) Descrizione del metodo
byte[]	readBytesFromTopJar(java.lang.String entryName) reads bytes from Top Jar file.
private void	readJarInJar() reads in self contained jar file this is the case if this class is jarred with other jar files so: FOO.jar +--Installer.class +--MetaJarClassLoader.class +--PACK1.jar +--ClassIWantToInvoke.class <===

Methods inherited from class java.lang.ClassLoader

, addClass, check, checkCerts, checkPackageAccess, compareCerts, defineClass, defineClass, defineClass, defineClass0, definePackage, findBootstrapClass, findBootstrapClass0, findLibrary, findLoadedClass, findNative, findResource, findResources, findSystemClass, getBootstrapClassPath, getBootstrapResource, getBootstrapResources, getCallerClassLoader, getDefaultDomain, getGetClassLoaderPerm, getPackage, getPackages, getParent, getResource, getResourceAsStream, getResources, getSystemClassLoader, getSystemResource, getSystemResourceAsStream, getSystemResources, initializePath, isAncestor, loadClass, loadClass, loadClassInternal, loadLibrary, loadLibrary0, resolveClass, resolveClass0, setSigners

Methods inherited from class java.lang.Object

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

Field Detail

jarFile

private java.lang.String jarFile

htSizes

private java.util.Hashtable htSizes

executingFromJar

private boolean executingFromJar

metaJarContent

private java.util.Hashtable metaJarContent

jarJarFile

private java.lang.String jarJarFile

metaManifest

private java.util.jar.Manifest metaManifest

Constructor Detail

BootstrapJarClassLoader

public BootstrapJarClassLoader(java.lang.String jFile)

constructor: decides if the jar filename passed belongs to a jar that: a) is outside the current class/jar file b) is inside the JAR file where this class is also stored.

Parameters:

jFile - jar file to load and use in classpath

Method Detail

main

public static void main(java.lang.String[] argv)

Descrizione del metodo

Parameters:

argv - Description of the Parameter

getActualJarName

public java.lang.String getActualJarName()

Legge l'attributo actualJarName dell object BootstrapJarClassLoader

Returns:

Il valore di actualJarName

readJarInJar

private void readJarInJar()

reads in self contained jar file this is the case if this class is jarred with other jar files so: FOO.jar +--Installer.class +--MetaJarClassLoader.class +--PACK1.jar +--ClassIWantToInvoke.class <===

getMainClassName

public java.lang.String getMainClassName()

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

Returns:

Il valore di mainClassName

invokeClass

public void invokeClass(java.lang.String name,
                        java.lang.String[] args)
                 throws java.lang.ClassNotFoundException,
                        java.lang.NoSuchMethodException,
                        java.lang.reflect.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 - Description of the Parameter

args - Description of the Parameter

Throws:

java.lang.ClassNotFoundException - Description of the Exception

java.lang.NoSuchMethodException - Description of the Exception

java.lang.reflect.InvocationTargetException - Description of the Exception

findClass

protected java.lang.Class findClass(java.lang.String className)
                             throws java.lang.ClassNotFoundException

method taht actually reads the class from raw bytes

Overrides:

findClass in class java.lang.ClassLoader

Parameters:

className - Description of the Parameter

Returns:

Description of the Return Value

Throws:

java.lang.ClassNotFoundException - Description of the Exception

initTopJarSizes

private void initTopJarSizes()

read sizes fror top-level JAR file. This can be the sole JAR file, or it can be used to read further into the JAR, for another JAR file JARRED :)

readBytesFromTopJar

public byte[] readBytesFromTopJar(java.lang.String entryName)

reads bytes from Top Jar file. Can be used standalone, or to read in another JAr file and then, using readJarInJar, filling the metaJarContent hashtable

Parameters:

entryName - Description of the Parameter

Returns:

Description of the Return Value

getTopJIS

private java.util.jar.JarInputStream getTopJIS()

get top level JAR input stream

Returns:

Il valore di topJIS

openResource

private java.io.InputStream openResource(java.lang.String filename)

Descrizione del metodo

Parameters:

filename - Description of the Parameter

Returns:

Description of the Return Value