Ndk-build displays a character error. The file is in the wrong format.

Question

I want to use the exiv2 library written in C ++ in my Android project. To do this, I am trying to cross-compile the library using the Android NDK.

To cross compile, follow these steps:

• Add ndk path to PATH variable

  $ PATH="/home/patrycja/android-packages/ndk:${PATH}"
  $ export PATH 
  

• Install the standard C / C ++ cross-compilation toolchain for Android.

  ./make-standalone-toolchain.sh --platform=android-21 --install-dir=/tmp/my-android-toolchain --ndk-dir='/home/patrycja/android-packages/ndk/' --toolchain=arm-linux-androideabi-4.9 --system=linux-x86_64
  
  Copying prebuilt binaries...
  Copying sysroot headers and libraries...
  Copying c++ runtime headers and libraries...
  Copying files to: /tmp/my-android-toolchain
  Cleaning up...
  Done.
  

• Set some environment variables so that the configuration and build process uses the correct compiler.

  $ export PATH=/tmp/my-android-toolchain/bin:$PATH
  $ export CC="arm-linux-androideabi-gcc"
  $ export CXX="arm-linux-androideabi-g++"
  $ export CFLAGS='-mthumb -O2' 
  $ export CXXFLAGS='-mthumb -O2' 
  $ export LDFLAGS='-Wl,--fix-cortex-a8' 
  $ export LIBS='-lstdc++ -lsupc++' 
  

• Block static library and sufficient headers

  ./configure --prefix=$(pwd)/build --host=arm-linux-androideabi --disable-shared --disable-xmp --disable-nls
  

As a result, I created the created assembly category files:

    ├── bin
    │   └── exiv2
    ├── include
    │   └── exiv2
    │       ├── *.hpp
    │
    ├── lib
    │   ├── libexiv2.a
    │   ├── libexiv2.la
    │   └── pkgconfig
    │       └── exiv2.pc
    └── share
        └── man
            └── man1
                └── exiv2.1

I copied to create a static library libexiv2.aand includein my Android project appName/src/main/jni/prebuild.

Android.mk as follows:

LOCAL_PATH := $(call my-dir)

#static library info
LOCAL_MODULE := exiv2
LOCAL_SRC_FILES := ../prebuild/libexiv2.a
LOCAL_EXPORT_C_INCLUDES := ../prebuild/include/
LOCAL_EXPORT_LDLIBS := -lz
include $(PREBUILT_STATIC_LIBRARY)


#wrapper info
include $(CLEAR_VARS)
LOCAL_C_INCLUDES += $(LOCAL_PATH)/../prebuild/include/
LOCAL_MODULE    := helloJNI
LOCAL_SRC_FILES := helloJNI.cpp
LOCAL_STATIC_LIBRARIES := exiv2
include $(BUILD_SHARED_LIBRARY)

Android . :

#include <string.h>
#include <jni.h>
#include <exiv2/exiv2.hpp>

extern "C" {

JNIEXPORT jstring JNICALL Java_com_example_patrycja_testndi2_MyActivity_helloJNI(JNIEnv *env, jobject thiz)
    {
        std::ostringstream os;
        std::string file("/storage/emmc/DCIM/100MEDIA/IMAG0021.jpg");
        Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(file);
        return env->NewStringUTF("asldjaljd");
    } 
}

ndk-build , .

[arm64-v8a] Compile++      : helloJNI <= helloJNI.cpp
[arm64-v8a] SharedLibrary  : libhelloJNI.so
jni/../prebuild/libexiv2.a: error adding symbols: File in wrong format
collect2: error: ld returned 1 exit status
make: *** [obj/local/arm64-v8a/libhelloJNI.so] Error 1

, - -. , - - . Ive : https://groups.google.com/forum/#!topic/android-ndk/mYh1LzMu_0U

Answer 1

exiv2 armv5 +, Lollipop. ndk-build , arm64-v8a, .

- ndk-build Android, , armv5, armv7, x86, x86_64, arm64-v8a...

--platform , SDK. ../prebuild/armeabi. x86:

./make-standalone-toolchain.sh --platform=android-9 --install-dir=/tmp/my-android-toolchain-x86 --ndk-dir='/home/patrycja/android-packages/ndk/' --arch=x86 --toolchain=x86-4.8 --system=linux-x86_64

$ export PATH=/tmp/my-android-toolchain-x86/bin:$PATH
$ export CC="i686-linux-android-gcc"
$ export CXX="i686-linux-android-g++"
$ export CFLAGS='-O2 -mtune=atom -mssse3 -mfpmath=sse' 
$ export CXXFLAGS='-O2 -mtune=atom -mssse3 -mfpmath=sse' 
$ export LDFLAGS='' 
$ export LIBS='-lstdc++ -lsupc++' 

./configure --prefix=$(pwd)/build-x86 --host=x86 --disable-shared --disable-xmp --disable-nls

.a ../prebuild/x86.

armeabi-v7a, mips, mips64, arm64-v8a.

, .a Android.mk TARGET_ARCH_ABI, :

LOCAL_PATH := $(call my-dir)

#static library info
LOCAL_MODULE := exiv2
LOCAL_SRC_FILES := ../prebuild/$(TARGET_ARCH_ABI)/libexiv2.a
LOCAL_EXPORT_C_INCLUDES := ../prebuild/include/
LOCAL_EXPORT_LDLIBS := -lz
include $(PREBUILT_STATIC_LIBRARY)

#wrapper info
include $(CLEAR_VARS)
LOCAL_C_INCLUDES += $(LOCAL_PATH)/../prebuild/include/
LOCAL_MODULE    := helloJNI
LOCAL_SRC_FILES := helloJNI.cpp
LOCAL_STATIC_LIBRARIES := exiv2
include $(BUILD_SHARED_LIBRARY)

Application.mk( , ), , :

APP_ABI := armeabi x86 # ideally, this should be set to "all"
APP_PLATFORM := android-14 # should the same as -platform and your minSdkVersion.