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Message-ID: <3F29E804.6000202@santafe.edu>
Date: Thu, 31 Jul 2003 22:09:40 -0600
From: "Marcus G. Daniels" <mgd AT santafe DOT edu>
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To: cygwin AT cygwin DOT com
Subject: loading DLLs created with Cygwin into Sun JDK
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I'm having a problem getting DLLs compiled with Cygwin to load into Sun 
JDK 1.4.1.  In the past this has worked, so I hope this is fixable 
without too much work.

Here's an example.  Take a simple Java Native Interface method like this:

$ cat jniTest.c
void Java_Test_test () { printf ("test\n");}

And compile it like so:

gcc -shared -o jniTest.dll jniTest.c

Also needed is the Java-side file:

public class Test {
   public native void test ();
   public static void main (String args[]) {
     Test test = new Test ();
     System.out.println ("loading jniTest");
     System.loadLibrary ("jniTest");
     System.out.println ("calling native method");
     test.test ();
     System.out.println ("success");
   }
}

Compiled it like so from a Cygwin terminal (replace 
/cygdrive/i/j2sdk1.4.1_02 as appropriate):

$ /cygdrive/i/j2sdk1.4.1_02/bin/javac Test.java

Now run it, you should see it print "loading jniTest", but nothing more.

$ CLASSPATH=. /cygdrive/i/j2sdk1.4.1_02/bin/java Test

In contrast, relink the DLL, but not using "-mno-cygwin":

$ gcc -mno-cygwin -shared -o jniTest.dll jniTest.c
$ CLASSPATH=. /cygdrive/i/j2sdk1.4.1_02/bin/java Test

Now it should print:

loading jniTest
calling native method
test
success




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