如何从Linux上的Java代码调用C函数

我正在关注教程

http://java.sun.com/developer/onlineTraining/Programming/JDCBook/jniexamp.html

到目前为止写了以下内容：

package com.ctest;

class CTest
{
    // Native method declaration
    native int testCall();

    // Load the library
    static
    {
        System.loadLibrary("fpdpReaderLib");
    }

    public static void main(String args[])
    {
        int retVal;

        // Create class instance
        CTest cLangTest = new CTest();

        // Call native method
        retVal = cLangTest.testCall();

        System.out.println(retVal);
    }
}

当我运行javac CTest.java时,我收到一个错误：

/usr/lib/gcc/i586-suse-linux/4.3/../../../crt1.o: in function '_start':
/usr/src/packages/BUILD/glibc-2.9/csu/../sysdeps/i386/elf/start.S:115: undefined reference to 'main'
/tmp/cc97kcJu.o:(.data+0x28) undefined reference to 'hidden alias for int com::ctest::CTest::testCall()'
/tmp/cc97kcJu.o:(.data+0x74) undefined reference to 'hidden alias for int com::ctest::CTest::testCall()'
collect2: ld returned 1 exit status

我怀疑它是使用gcc而不是java版本的javac,但我不确定.

任何想法可能是什么问题？

我尝试过使用这里提到的“–main =”选项：

http://gcc.gnu.org/java/faq.html#4_1

但在我现在得到之前,而不是错误：

/tmp/ccwfugWq.o:(.data+0x28) undefined reference to 'hidden alias for int com::ctest::CTest::testCall()'
/tmp/ccwfugWq.o:(.data+0x74) undefined reference to 'hidden alias for int com::ctest::CTest::testCall()'
collect2: ld returned 1 exit status