How to create native C++ library on Android?

Question

I need to write a dynamic link library in C++ that is used by Java on Android. As I get, it should be .so library, but I don't know how to do that. I tried Cygwin, but it crashes:

$ gcc 1.cpp

/usr/lib/gcc/i686-pc-cygwin/4.3.4/../../../../i686-pc-cygwin/bin/ld: cannot find -luser32 collect2: ld returned 1 exit status

1.cpp:
int main(int, char**)
{
   return 0;
}

Can anyone help me with that?

P.S. I'm not good at *nix, so it should be better done under Windows

UPD: I've installed both Android NDK and Cygwin and added them to PATH environment variable

UPD2: Thanks for helping. The problem was with Cygwin itself. Reinstalling it and NDK solved the problem.

Answer 1

For your example, use g++ instead of gcc, its a C++ program.

Look at the hello-jni sample in the NDK. You need to build your shared library using the NDK and import it into a Java Android project. In the Java code, you need to declare the native functions with 'native' and add the library using static; see snippet below.

public native String  stringFromJNI();

static {
    System.loadLibrary("hello-jni");
}