Bug 263779

Description John Vandenbroek 2009-02-05 08:23:42 EST

Created attachment 124797 [details]
Contains classes showing failures

Build ID: 3.4.0 - I20080617-2000

Steps To Reproduce:


More information:

Both the Sun JRE and the IBM JRE cannot load classes which reside in package "java".  The JDT should issue an error message when:

1) The user creates a package named "java",
2) A Java class resides in package "java".  This class may have been created
   on the user's behalf by a generation tool.

I have provided an attachment JAR which contains three classes:

1) java.JavaTest - which issues the following error when I invoke its main()
   method:

	Exception in thread "main" java.lang.NoClassDefFoundError: java.JavaTest
	Caused by: java.lang.ClassNotFoundException: java.JavaTest
	        at java.net.URLClassLoader.findClass(URLClassLoader.java:419)
	        at java.lang.ClassLoader.loadClass(ClassLoader.java:643)
	        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:300)
	        at java.lang.ClassLoader.loadClass(ClassLoader.java:609)

2) test.JavaTestClient - which has a main() method which tries to create an
   instance of class java.JavaTest.  When I call its main() method the
   following error is issued:

	Running JavaTestClient.main()
	Exception in thread "main" java.lang.SecurityException: java.JavaClass - protected system package 'java'
	        at java.lang.ClassLoader.checkClassName(ClassLoader.java:211)
	        at java.lang.ClassLoader.defineClass(ClassLoader.java:253)
	        at java.security.SecureClassLoader.defineClass(Unknown Source)
	        at java.net.URLClassLoader.defineClass(URLClassLoader.java:493)
	        at java.net.URLClassLoader.access$300(URLClassLoader.java:64)
	        at java.net.URLClassLoader$ClassFinder.run(URLClassLoader.java:892)
	        at java.security.AccessController.doPrivileged(AccessController.java:284)
	        at java.net.URLClassLoader.findClass(URLClassLoader.java:414)
	        at java.lang.ClassLoader.loadClass(ClassLoader.java:643)
	        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:300)
	        at java.lang.ClassLoader.loadClass(ClassLoader.java:609)
	        at other.JavaTestClient.main(JavaTestClient.java:8)

3) other.OtherTest - which has a main() method which does not interact with
   class java.JavaTest.  This main() method runs without an error.

The following web page addresses this restriction:  

   http://www.mail-archive.com/java-linux@java.blackdown.org/msg15876.html

Here is an excerpt:

>> <AFAIK>
>> java, javax, and sun are among the package names reserved for the virtual
>> machine.  In order to prevent a trojan horse attack, users cannot add or
>> detract from these namespaces.
>> </AFAIK>

I assume "AFAIK" means "as far as I know", which means that this statement isn't definite.  But, taken in light of the above evidence, I'm inclined to believe the statement is true.