Why won't -Djava.system.class.loader make it use my ClassLoader?

I created a class MyAppLoader and installed it in the bootclasspath and used the system property -Djava.system.class.loader. Yet, the JVM won't use my classloader! It's never instantiated (I have a static bit that prints code if it's loaded at all).
How do I make the JVM use my class as the system classloader?

send to me some Duke, please Any particular one? I hear the Duke of Northumberland is quite a laugh - would he do?

Similar Messages

Replacing system class loader

Hi!
I'm trying to replace the system class loader for plugin management reasons. I've written a simple test app for testing, but it doesn't work. The first code is a ClassLoader, the second is the main code.
I try to run the code like this: java -Xbootclasspath/a:. -Djava.system.class.loader=A -cp . B
It uses my classloader every time, except for when I call Class.forName(). What could be the problem?
Thanks, Bal�zs
public class A extends java.lang.ClassLoader {
public A(ClassLoader parent) {
super(parent);
System.out.println("A loaded, parent is " + parent);
public Class loadClass(String name) throws java.lang.ClassNotFoundException {
try {
Class c = getParent().loadClass(name);
System.out.println("A was asked for " + name + " and delegated it to " + getParent());
return c;
} catch (ClassNotFoundException e) {
System.out.println("A was asked for " + name + " but didn't find it");
throw new ClassNotFoundException(name + " not found :[");
}; // ENDOF CLASS A
public class B {
public static void main(String[] args) {
(new B()).proc();
private void proc() {
System.out.println("Hello World!");
System.out.println("Class loader: " + getClass().getClassLoader());
try {
Class.forName("C");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}; // ENDOF CLASS B

Thanks for the reply. I think I've got a much better idea of how this stuff works now. I think what I need to do is register my deserializer with SOAP as a class that will really load the deserializer using Class.forName() with my class loader as a parameter. Then when the bootstrap class loader can't find a class, findClass() in my classloader will be called and I can load it from a URL.
Should work.
Thanks very much!

How to load a class dynamically in the current/system class loader

I need to dynamically load a new jdbc driver jar to the current/system class loader... Please note that creating a new classloader will not help since the DriverManager refers to the systemclassloader itself.
Restarting the application by appending the jar to its classpath will solve the problem but I want to avoid doing this.

Did you then create a ClassLoader to load the JDBC
driver and then install it into the system as
directed by the JDBC specification (ie
Class.forName(someClassName))?
And then try to use it from a class loaded fromsome
other ClassLoader (i.e. the system class loader)?
If you did not try this please explain why not.O.K. I just looked at the source to
java.sql.DriverManager. I did not know what I was
talking about, as what I suggested above will not
work.
This is my new Idea:
Create a URLClassLoader to load the JDBC driver also
in this ClassLoader you need to place a helper class
that does the following:
public class Helper {
public Driver getJDBCDriver(String driverClassName,
String url) {
try {
Class.forName(driverClassName);
Driver d = DriverManager.getDriver(url);
return d;
catch(Exception ex) {
ex.printStackTrace();
return null;
}Now create an instance of the Helper class in the new
ClassLoader, and call its getJDBCDriver method to get
an instance of the driver (you will probably have to
create an interface in the root class loader that the
Helper implements so that you can easily call it).
Now from the root classloader you can make calls
directly to the returned Driver and bypass the
DriverManager and its restrictions on cross
ClassLoader access.
The only catch here is that you would have to call to
the returned Driver directly and not use the Driver
Manager.This sounds like will work but I did not want to load DriverManager in a new classloader.. I did a hack
I unzip the jar dynamically in a previously known location (which I included in my classpath when launching the app). The classLoader finds the class now though it did not exist when the app was launched !
A hack of-course but works eh ..

WTF does this mean and why won't my illustrator CS5 load without this appearing?? Exit Code: 6 -------------------------------------- Summary -------------------------------------- - 0 fatal error(s), 5 error(s), 4 warning(s) WARNING: LocalizeFile:Local

WTF does this mean and why won't my illustrator CS5 load without this appearing??
Exit Code: 6
-------------------------------------- Summary --------------------------------------
- 0 fatal error(s), 5 error(s), 4 warning(s)
WARNING: LocalizeFile:Localized string not found for locale 'en_GB' try fetching for en_US
WARNING: LocalizeFile:Localized string not found for locale 'en_GB' try fetching for en_US
WARNING: LocalizeFile:Localized string not found for locale 'en_GB' try fetching for en_US
WARNING: LocalizeFile:Localized string not found for locale 'en_GB' try fetching for en_US
ERROR: 92 Unable to copy file from "/private/tmp/.tempdirYoCObExG/Assets1/Application/Cool Extras.localized/en_GB/Sample Files/Sample Art/Crowd.ai" to "/Applications/Adobe Illustrator CS5/Cool Extras.localized/en_GB/Sample Files/Sample Art/Crowd.ai" Error 0
ERROR: 92 Command ARKCopyFileCommand failed.
ERROR: The following payload errors were found during install:
ERROR: - Adobe Illustrator CS5_AdobeIllustrator15en_GBLanguagePack: Install failed
ERROR: - Adobe Illustrator CS5: Failed due to Language Pack installation failure
AND HOW DO I FIX THE PROBLEM???????

Exit Code 6 and Exit Code 7 indicate that the installation finished with errors. However, the exit codes themselves do not indicate the type of error that occurred.
Please refer to :
Errors "Exit Code: 6," "Exit Code: 7" | CS5, CS5.5
Error "Exit 6" or "Exit 7" | Install log | Read, write, system file errors | CS5, CS5.5
Regards
Rajshree

Why won't my Mac Pro load things without locking up ?

Why won't my Mac Pro load things or let me do a "save as" without locking up ? I have tried to run the Apple Hardware Test and it locks up as well.

you have anitebook in forum for 65lbs towers
youneed to repair your disk directory or erase and restore
and use Recovery Mode in 10.7 and later
AHT does not lick up, not unless your laptop RAM or mobo has failed totally and died, more common for laptops that overheat, sufferwater damage, but still...
depends on how new what to do, might try macbookmpro forum.

Why won't my computer let me make changes to documents??

Why won't my computer let me make changes to documents saved in pages and save them again? It keeps saying access denied when its my computer and I have Lion OS X

Right click the document and select 'get info'. Check the permissions for the file. If several of these files have the wrong permissions then you may need to repair user permissions. See this for instructions:
http://osxdaily.com/2011/11/15/repair-user-permissions-in-mac-os-x-lion/

Why won't my sound effects load up dials?

Why won't my Premier Elements load up sound effects dials??

Exactly which Audio Effects are you talking about?
Also, when one experiences GUI display issues (many of the Effects have animated settings panels), I always recommend that they go to the nVidia, or AMD/ATI Web site (depending on the mfgr. of their video card), download and install the very latest video driver. Even if that is not the solution to the display, it gets a common problem out of the way early.
Good luck, and please let us know just a bit more.
Hunt

System class loader vs application class loader

Hello
I have a class that uses a third partyjar which I have put in /jre/lit/ext. The class compiles but fails at runtime being unable to read the property files called in the class' constructor. I believe that is b/c the third party jars are loading w/ the system class loader and cannot "see" the property files "floating" at the same level as the class that is calling them.
So I created a jar, of the property files, with the same directory/package structure as the location of the property files and put that in the /jre/lib/ext and STILL the same problem; cannot read the property files, the constructor fails, fugly. There is an overloaded constructor that includes a parameter for the property files, but I need to get this to work as is first. What am I missing? Please edify me. tia.

If the 3rd party jar needs a certain properties file to initialize correctly, I doubt it would be looking for it in the class hierarchy. I mean I doubt it does:
Properties p = new Properties();
p.load( getClass().getResourceAsStream() );It's more likely to do:
Properties p = new Properties();
p.load( new FileInputStream(...) );The reason is that the property file should be easily edited by the user and users know how to move around in the file system, not in the Java jars and classpaths.
Just a guess...

Problem loading modified classes from CLASSPATH using system class loader

Hi,
I am facing problem to load the modified classes from CLASSPATH.
I have set my CLASSPATH to a directory whose classes will be modified frequently. After the server(web/app) is started, the system class loader, using which am trying to load the classes from the directory where the CLASSPATH is set, am not able to load the modified files without the server restart.
Do I need to have a custom class loader to fix this.
Please help me.
Thanks,
Sureddy

Do I need to have a custom class loader to fix this.Yes.

Why won't my system won't suut down after software update?

why won't my system won't suut down after software update?

That's an annoying issue. Disconnect all USB devices such as Pen drives and external HDDs before doing the update.

Why won't Netflix nor iTunes load on my iPad and iPhone since I downloaded iOS7 and I OS 7.0.2?

Why won't Netflix nor iTunes load on my iPad and iPhone since I downloaded iOS7 and I OS 7.0.2?

Sounds like you may need to re-download the entire albums from iTunes. See this KB article for how to download past purchases: http://support.apple.com/kb/HT2519.
I'd suggest doing it one album at a time. Delete one, download it from your purchase histor, then the next, etc.

HT1338 I have Mac OS X v10.6, Java SE6 v1.6.0, why won't my Pogo games load?

I have Mac OS X v10.6, Java SE6 v1.6.0, why won't my Pogo games load?

Is this played in your browser? If so is java enabled in the browser (for example, Safari preferences, security. enable java)?
If enabled there is it enabled globally (Java Preferences in Utilities, General, check the two checkboxes or click Restore Defaults)?

Why won't my icloud desktop load? It just keeps running, but not loading

Why won't my icoud desktop load? For the past 2 days, it just keeps running without ever loading.

you don't need to uninstall your cs6 products.
did you run the cleaner between uninstalling and reinstalling? if yes, contact adobe support, Contact Customer Care

Does resteasy API have class loader issues when using via OSGi

Does resteasy API have class loader issues when using via OSGi

Hi Scott,
THis isnt an answer to ur Question, but could u tell me which jar files are needed for the packages:
com.sap.portal.pcm.system.ISystems
com.sap.portal.pcm.system.ISystem
and under which path I coul dfind them.
Thnx
Regards
Meesum.

HT201303 the money in the credit card i was using to pay for apps got exhausted and i bought some apps on credit without knowing ... ive tried to use another credit card to pay, but still won't accept, nor allow me make maximum use of my apple id .... pls

the money in the credit card i was using to pay for apps got exhausted and i bought some apps on credit without knowing ... ive tried to use another credit card to pay, but still won't accept, nor allow me make maximum use of my apple id .... pls help.

Detail "won't accept".

Why won't -Djava.system.class.loader make it use my ClassLoader?

Similar Messages

Maybe you are looking for