Android NDK 运行时错误

Question

我已经关注了这个链接

How to link any library in ndk application

我的文件夹结构如下所示

项目（项目根目录）
|->src
|-->com.apparmtest
|--->主活动
|->jni
|-->Android.mk
|-->Application.mk
|-->AppARMTest.c
|-->com_apparmtest_MainActivity.h
|->我的库
|-->文件测试.h
|-->libFRead.so

而我的 Android.mk 文件内容是

Android.mk

LOCAL_PATH := $(call my-dir)


### include FileTest.so as a prebuilt lib ###

include $(CLEAR_VARS)


LOCAL_MODULE            := my-prebuilt-lib

LOCAL_SRC_FILES         := ../myLib/libFRead.so

LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/../myLib


include $(PREBUILT_SHARED_LIBRARY)

### end prebuilt###

include $(CLEAR_VARS)

LOCAL_MODULE    := AppARMTest

LOCAL_C_INCLUDES := $(LOCAL_PATH) \
                $(LOCAL_PATH)/../myLib

LOCAL_SRC_FILES := AppARMTest.c

LOCAL_LDLIBS := -llog

LOCAL_STATIC_LIBRARIES := my-prebuilt-lib

include $(BUILD_SHARED_LIBRARY)


and my Application.mk contains 


APP_MODULES := AppARMTest

APP_PLATFORM := ANDROID-8


and this project is compiling properly as well as ndk-build is not giving any error.

But while running on emmulator I am getting this error



    10-19 10:25:40.704: E/AndroidRuntime(334): FATAL EXCEPTION: main

    10-19 10:25:40.704: E/AndroidRuntime(334): java.lang.ExceptionInInitializerError

    10-19 10:25:40.704: E/AndroidRuntime(334):  at java.lang.Class.newInstanceImpl(Native Method)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at java.lang.Class.newInstance(Class.java:1409)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    android.app.Instrumentation.newActivity(Instrumentation.java:1021)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1561)


    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    android.app.ActivityThread.access$1500(ActivityThread.java:117)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    android.os.Handler.dispatchMessage(Handler.java:99)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at android.os.Looper.loop(Looper.java:123)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    android.app.ActivityThread.main(ActivityThread.java:3683)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at java.lang.reflect.Method.invokeNative(Native Method)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    java.lang.reflect.Method.invoke(Method.java:507)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at 

    com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)

    10-19 10:25:40.704: E/AndroidRuntime(334):  at dalvik.system.NativeStart.main(Native Method)

    10-19 10:25:40.704: E/AndroidRuntime(334): Caused by: java.lang.UnsatisfiedLinkError: Cannot load library: link_image[1962]:    33 could not load needed library

    './obj/local/armeabi/libFRead.so' for 'libAppARMTest.so' (load_library[1104]: Library './obj/local/armeabi/libFRead.so' not found)

   10-19 10:25:40.704: E/AndroidRuntime(334):   at java.lang.Runtime.loadLibrary(Runtime.java:434)

   10-19 10:25:40.704: E/AndroidRuntime(334):   at java.lang.System.loadLibrary(System.java:554)

   10-19 10:25:40.704: E/AndroidRuntime(334):   at ivz.apparmtest.MainActivity.<clinit>(MainActivity.java:11)

   10-19 10:25:40.704: E/AndroidRuntime(334):   ... 15 more

Answer 1

这是一个运行时链接问题。运行环境找不到libAppARMTest.so需要的库libFRead.so

这个问题在你执行ndk-build的时候不会出现，因为你已经在makefile中明确说明了libFRead.so的路径，所以编译工作正常。

尝试确保 dalvik 能够在运行时加载 libFRead.so。您可能需要将库 libFRead.so 与 libAppARMTest.so 一起放在 libs/armeabi 文件夹中。

Answer 2

在MainActivity类的静态构造函数中调用loadLibrary()两次：

static {
    System.loadLibrary("FRead");
    System.loadLibrary("AppARMTest");
}