NDK-Use of .a file in C file

Question

I'm trying to use a .a file in my C code to use in Java (sorry for my bad English). I created myself a static library named libtest.a. now when i include files present in that library in gives me error as no such file or directory.

i have put the libtest.a in the same folder where my Android.mk and Application.mk resides

C-code:

#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <jni.h>
#include <exp.h> //the header in libtest.a

And this is my makefile:

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := libtest
LOCAL_SRC_FILES := libtest.a

include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := socket
LOCAL_SRC_FILES := source/interface.c source/file.c
LOCAL_LDFLAGS += libtest.a  

include $(BUILD_SHARED_LIBRARY)

When I compile it, I get the following error

error: exp.h: No such file or directory

I want to use the .a without it's code so I hope I'm clear enough.

Answer 1

as i have changed my .mk file

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := libtest
LOCAL_SRC_FILES := libtest.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../../libtest/jni/include
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := socket
LOCAL_SRC_FILES := source/interface.c source/file.c
LOCAL_STATIC_LIBRARIES += libtest
include $(BUILD_SHARED_LIBRARY)

Answer 2

There are no header files in .a file, only the compiled code which is essentially a stream of bytes, not the encoded .h-files . This it NOT Java. To use your libtest.a you must supply the exp.h file and whatever the dependent header files are.

You should use LOCAL_STATIC_LIBRARIES for that.

include $(CLEAR_VARS)
LOCAL_MODULE    := libtest
LOCAL_SRC_FILES := libtest.a
include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := socket
LOCAL_SRC_FILES := source/interface.c source/file.c
LOCAL_STATIC_LIBRARIES += libtest

include $(BUILD_SHARED_LIBRARY)