Overview  Package   Class  Use  Deprecated  Index
Home >> All >> com >> simscomputing >> [ testbed overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

com.simscomputing.testbed
Class FileSystemClassLoader  

java.lang.Object
  java.lang.ClassLoader
      java.security.SecureClassLoader
          java.net.URLClassLoader
              com.simscomputing.testbed.FileSystemClassLoader

---

public class FileSystemClassLoader

extends java.net.URLClassLoader

This class is almost a trivial subclass of URLClassLoader. The one thing that I'm baffled by is that if I overload loadClass(), then newly loaded classes have their class loader set to this class. If I don't, then new classes have their class loader set to the primordial class loader. I've no idea why this behaves this way. I've tested it under Linux JDK 1.2 and Windows JDK 1.3 beta. I need newly loaded classes to have their class loader set to FileSystemClassLoader so that can be reloaded when the user clicks "Re-Exercise". Why not just find the class file in the file system and call defineClass() like almost all other custom class loaders do? Because it gets real tricky when you're trying to load classes from signed jar files and the like. I figured that since URLClassLoader has already gone to all the trouble to do these things for me, why not use it? The only downside so far is that classes loaded from the CLASSPATH, and not the TestClassPath, have their class loader set to the primordial one, which means they can't be re-exercised properly. This is why we have the concept of the TestClassPath. But even with this problem, the benefits outweigh the drawbacks. I get to reuse a lot of JDK code which works properly even under tricky security situations. Please let me know if you have some insight into this situation. david@simscomputing.com

Version:

$Revision: 1.1.1.1 $ $Date: 2000/02/21 21:22:33 $

---

Nested Class Summary

 

Nested classes inherited from class java.net.URLClassLoader

 

Nested classes inherited from class java.lang.ClassLoader

 

Field Summary
private  java.lang.String	classPath
private  boolean	debug
private  java.lang.ClassLoader	exemptClassLoader
private  java.util.ArrayList	exemptPackagePrefixList
private  boolean	second
private  java.util.ArrayList	storageUnits

 

Fields inherited from class java.net.URLClassLoader

 

Fields inherited from class java.security.SecureClassLoader

 

Fields inherited from class java.lang.ClassLoader

 

Constructor Summary

FileSystemClassLoader(java.net.URL[] urls, java.lang.ClassLoader exemptClassLoader)

 

Method Summary
java.lang.Class	loadClass(java.io.File file)
java.lang.Class	loadClass(java.lang.String name, boolean resolve)           According the JDK source, loadClass is supposed to be declared as synchronzied.
java.lang.String	toString()           Returns a String representation of this URLClassLoader giving the actual Class name, the URLs that are searched and the parent ClassLoader.

 

Methods inherited from class java.net.URLClassLoader

addURL, definePackage, findClass, findResource, findResources, getPermissions, getURLs, newInstance, newInstance

 

Methods inherited from class java.security.SecureClassLoader

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, resolveClass, setClassAssertionStatus, setDefaultAssertionStatus, setPackageAssertionStatus, setSigners

 

Methods inherited from class java.lang.Object

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

 

Field Detail

classPath

private java.lang.String classPath

---

storageUnits

private java.util.ArrayList storageUnits

---

debug

private boolean debug

---

exemptClassLoader

private java.lang.ClassLoader exemptClassLoader

---

exemptPackagePrefixList

private java.util.ArrayList exemptPackagePrefixList

---

second

private boolean second

Constructor Detail

FileSystemClassLoader

public FileSystemClassLoader(java.net.URL[] urls,
                             java.lang.ClassLoader exemptClassLoader)

Method Detail

loadClass

public java.lang.Class loadClass(java.io.File file)
                          throws java.lang.ClassNotFoundException

---

toString

public java.lang.String toString()

Description copied from class: java.net.URLClassLoader

Returns a String representation of this URLClassLoader giving the actual Class name, the URLs that are searched and the parent ClassLoader.

---

loadClass

public java.lang.Class loadClass(java.lang.String name,
                                 boolean resolve)
                          throws java.lang.ClassNotFoundException

According the JDK source, loadClass is supposed to be declared as synchronzied. For reasons unknown, if this method is commented out, all classes loaded by this class loader will have their class loader set to primordial class loader, NOT this class (FileSystemClassLoader).

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> com >> simscomputing >> [ testbed overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---