I'm using $CATALINA_HOME/lib, not $CATALINA_HOME/common/lib. I wonder if the
problem is specific to using common/lib?
Jon
----- Original Message -----
From: "Jochen Schneider" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Monday, September 17, 2001 3:06 AM
Subject: Re: Thanks for the note on JNI and class loading in the release
notes
> Hi Jonathan,
>
> we had the same problem and fixed it in the way described now in the
Tomcat
> documentation.
>
> Probably one additional remark should be added to the documentation :
>
> If you place the Java code loading the native library outside of the web
> application (for example in $CATALINA_HOME/common/lib) it is loaded only
> once and the problem is solved.
>
> This sollution has some implication : The classes containing the native
code
> are loaded by a classloader which has no knowledge about any class which
> resides in \Web-inf\lib. You will get an exception if you try to
instanciate
> a class which resides in the \Web-inf\lib directory from your native code!
> You will also get an exception if you try to import a class which resides
in
> the \Web-inf\lib\ directory from your java code in
$CATALINA_HOME/common/lib
> since the two classes are loaded by different classloaders.
>
> This will not work (ClassA in $CATALINA_HOME/common/lib ansd ClassB in
> \Web-inf\lib\ ) :
>
> ClassA :
>
> import ClassB;
> public native static void doSomething(ClassB obj);
>
>
> ClassB :
>
> import ClassA
> public static void main(String[] args) {
> ClassA.doSomething(this);
> }
>
>
> Now it works again :
>
> ClassA :
>
>
> public native static void doSomething(Object obj);
>
>
> ClassB :
>
> import ClassA
> public static void main(String[] args) {
> ClassA.doSomething((Object)this);
> }
>
>
> Is this description correct? How do you handle this problem? Is there a
more
> elegant sollution ?
>
> Regards,
> Jochen
>
>
>
>
>
> -------------------------------------
> Tomcat 4.0 and JNI Based Applications:
> -------------------------------------
>
> Applications that require native libraries must ensure that the libraries
> have
> been loaded prior to use. Typically, this is done with a call like:
>
> static {
> System.loadLibrary("path-to-library-file");
> }
>
> in some class. However, the application must also ensure that the library
> is
> not loaded more than once. If the above code were placed in a class
inside
> the web application (i.e. under /WEB-INF/classes or /WEB-INF/lib), and the
> application were reloaded, the loadLibrary() call would be attempted a
> second
> time.
>
> To avoid this problem, place classes that load native libraries outside of
> the
> web application, and ensure that the loadLibrary() call is executed only
> once
> during the lifetime of a particular JVM.
>
>
>
> ----- Original Message -----
> From: "Jonathan Eric Miller" <[EMAIL PROTECTED]>
> To: "Tomcat Developer List" <[EMAIL PROTECTED]>
> Sent: Saturday, September 15, 2001 5:59 AM
> Subject: Thanks for the note on JNI and class loading in the release notes
>
>
> > I'm guessing that Craig is the one that added the section about JNI and
> > class loading in the RC1 release notes. I just wanted to say that I
> > appreciate that you documented this.
> >
> > I also noticed that you fixed a problem that I noticed with the Base64
> > encoder where it had trailing zeroes.
> >
> > Thanks, Jon
> >
> >
>
>
>
>
