I'm trying to create a simple Java app that uses JNI to call some native functions. I've followed the examples in the JNI Programming Guide and can't seem to get them to work. I have the following Hello World
program, written in Java:
class HelloWorld {
private native void print();
public static void main(String [] args) {
new HelloWorld().print();
}
static {
System.load("/home/mike/Desktop/libHelloWorld.so");
}
}
I compile it using javac HelloWorld.java, just like normal. Then I run javah -jni HelloWorld, and finally the following:
gcc34 -shared -fpic -o libHelloWorld.so -I/<path to JDK>/include -I/<path to JDK>/include/linux HelloWorld.c
gcc34 is the name of the GCC
program on my machine here at work (I don't control that) and I obviously place the real path to the JDK in that command. When I run my
program, using the standard java HelloWorld, I get an error saying the following:
Exception in thread "main" java.lang.UnsatisfiedLinkError: /home/mike/Desktop/libHelloWorld.so: /home/mike/Desktop/libHelloWorld.so: wrong ELF class: ELFCLASS64 (Possible causes: architecture word width mismatch)
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1778)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1674)
at java.lang.Runtime.load0(Runtime.java:770)
at java.lang.System.load(System.java:1003)
at HelloWorld.<clinit>(HelloWorld.java:8)
Could not find the main class: HelloWorld.
Program will exit.
I know I'm running a 32-bit JVM (and unfortunately, as of right now, I'm not allowed to get a 64-bit JVM). I tried telling GCC to compile in 32-bit mode using the "-m32" option, but we don't have (and again, can't get) what we need for that.
Does this sound like a 32/64-bit conflict or something else?
