NDK构建不创建.so文件

Question

我正在尝试构建一个本地库，名为receiptrecognizer，它是从Android应用程序调用的。

我认为我正确设置了所有内容，因为NDK-build没有显示任何错误。但是，当我调用System.loadLibrary("receiptrecognizer");时，我会得到一个UnsatisfiedLinkError。

原因是没有libreceiptidentifier.so文件在apk内部。实际上没有libreceiptidentifier.so文件当我运行ndk构建时在任何地方创建。

为什么没有生成.so文件

receiptrecognizer使用openCV和tesseract（后者反过来使用leptonica）。

这是我的Android.mk:

    LOCAL_PATH := $(call my-dir)
    include $(CLEAR_VARS)
    OPENCV_CAMERA_MODULES:=on
    OPENCV_INSTALL_MODULES:=on
    OPENCV_LIB_TYPE:=SHARED
    include ../opencv4android/sdk/native/jni/OpenCV.mk
    include $(CLEAR_VARS)
    LOCAL_MODULE := lept
    LOCAL_SRC_FILES := ../../tess-two/libs/$(TARGET_ARCH_ABI)/liblept.so
    include $(PREBUILT_SHARED_LIBRARY)
    include $(CLEAR_VARS)
    LOCAL_MODULE := tess
    LOCAL_SRC_FILES := ../../tess-two/libs/$(TARGET_ARCH_ABI)/libtess.so
    include $(PREBUILT_SHARED_LIBRARY)

    LOCAL_MODULE    := receiptrecognizer
    LOCAL_SRC_FILES := 
        src/OCRImagePreprocessor.cpp 
        src/util.cpp 
        ocrimagepreprocessorjni.cpp
    LOCAL_C_INCLUDES := 
      $(LOCAL_PATH)/../../opencv4android/sdk/native/jni/include 
      $(LOCAL_PATH)/../../tess-two/jni/com_googlecode_leptonica_android/src/src 
      $(LOCAL_PATH)/../../tess-two/jni/com_googlecode_tesseract_android/src 
      $(LOCAL_PATH)/../../tess-two/jni/com_googlecode_tesseract_android/src/ccutil 
      $(LOCAL_PATH)/../../tess-two/jni/com_googlecode_tesseract_android/src/ccstruct 
      $(LOCAL_PATH)/../../tess-two/jni/com_googlecode_tesseract_android/src/ccmain 
      $(LOCAL_PATH)/jni/src 
      $(LOCAL_PATH)/jni 
      $(LOCAL_PATH)/src 
      $(LOCAL_PATH)
    LOCAL_CFLAGS := 
      --std=c++11
    LOCAL_SHARED_LIBRARIES := 
        opencv_java3 
        lept 
        tess
    include $(BUILD_SHARED_LIBRARY)

这里是ndk-build的输出（除了一些关于覆盖目标命令的警告）：

[armeabi] Prebuilt       : liblept.so <= jni/../../tess-two/libs/armeabi/
[armeabi] Install        : liblept.so => libs/armeabi/liblept.so
[armeabi] Prebuilt       : libopencv_java3.so <= ../opencv4android/sdk/native/jni/../libs/armeabi/
[armeabi] Install        : libopencv_java3.so => libs/armeabi/libopencv_java3.so
[armeabi] Compile++ thumb: receiptrecognizer <= OCRImagePreprocessor.cpp
[armeabi] Compile++ thumb: receiptrecognizer <= util.cpp
[armeabi] Compile++ thumb: receiptrecognizer <= ocrimagepreprocessorjni.cpp
make.exe: Circular obj/local/armeabi/libtess.so <- obj/local/armeabi/libtess.so dependency dropped.
[armeabi] Prebuilt       : libtess.so <= obj/local/armeabi/objs/receiptrecognizer/src/
[armeabi] Install        : libtess.so => libs/armeabi/libtess.so
[armeabi-v7a] Prebuilt       : liblept.so <= jni/../../tess-two/libs/armeabi-v7a/
[armeabi-v7a] Install        : liblept.so => libs/armeabi-v7a/liblept.so
[armeabi-v7a] Prebuilt       : libopencv_java3.so <= ../opencv4android/sdk/native/jni/../libs/armeabi-v7a/
[armeabi-v7a] Install        : libopencv_java3.so => libs/armeabi-v7a/libopencv_java3.so
[armeabi-v7a] Compile++ thumb: receiptrecognizer <= OCRImagePreprocessor.cpp
[armeabi-v7a] Compile++ thumb: receiptrecognizer <= util.cpp
[armeabi-v7a] Compile++ thumb: receiptrecognizer <= ocrimagepreprocessorjni.cpp
make.exe: Circular obj/local/armeabi-v7a/libtess.so <- obj/local/armeabi-v7a/libtess.so dependency dropped.
[armeabi-v7a] Prebuilt       : libtess.so <= obj/local/armeabi-v7a/objs/receiptrecognizer/src/
[armeabi-v7a] Install        : libtess.so => libs/armeabi-v7a/libtess.so
[x86] Prebuilt       : liblept.so <= jni/../../tess-two/libs/x86/
[x86] Install        : liblept.so => libs/x86/liblept.so
[x86] Prebuilt       : libopencv_java3.so <= ../opencv4android/sdk/native/jni/../libs/x86/
[x86] Install        : libopencv_java3.so => libs/x86/libopencv_java3.so
[x86] Compile++      : receiptrecognizer <= OCRImagePreprocessor.cpp
[x86] Compile++      : receiptrecognizer <= util.cpp
[x86] Compile++      : receiptrecognizer <= ocrimagepreprocessorjni.cpp
make.exe: Circular obj/local/x86/libtess.so <- obj/local/x86/libtess.so dependency dropped.
[x86] Prebuilt       : libtess.so <= obj/local/x86/objs/receiptrecognizer/src/
[x86] Install        : libtess.so => libs/x86/libtess.so
[mips] Prebuilt       : liblept.so <= jni/../../tess-two/libs/mips/
[mips] Install        : liblept.so => libs/mips/liblept.so
[mips] Prebuilt       : libopencv_java3.so <= ../opencv4android/sdk/native/jni/../libs/mips/
[mips] Install        : libopencv_java3.so => libs/mips/libopencv_java3.so
[mips] Compile++      : receiptrecognizer <= OCRImagePreprocessor.cpp
[mips] Compile++      : receiptrecognizer <= util.cpp
[mips] Compile++      : receiptrecognizer <= ocrimagepreprocessorjni.cpp
make.exe: Circular obj/local/mips/libtess.so <- obj/local/mips/libtess.so dependency dropped.
[mips] Prebuilt       : libtess.so <= obj/local/mips/objs/receiptrecognizer/src/
[mips] Install        : libtess.so => libs/mips/libtess.so

欢迎提出任何想法。

Answer 1

在您显示的ndk-build的跟踪中，我看到这行make.exe: Circular obj/local/mips/libtess.so <- obj/local/mips/libtess.so dependency dropped.

我认为这就是为什么您没有生成正确的.so库的原因。我想你忘了在LOCAL_MODULE := receiptrecognizer之前加一个include $(CLEAR_VARS)。

我希望这对你有用。