android - NDK-build 不会创建 .so 文件

Question

我正在尝试构建一个本地库，称为 receipetrecognizer，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，我得到一个 UnsatisfiedLinkError。

这是因为没有libreceiptrecognizer.so文件在 apk 中。实际上没有 libreceiptrecognizer.so 文件当我运行 ndk-build 时在任何地方创建。

为什么没有生成.so文件？

receiptrecognizer 使用 openCV 和 tesseract(后者又使用 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)

下面是 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

欢迎任何想法。

Answer 1

在来自 ndk-build 的跟踪中你显示，我看到这一行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正确的 .so生成的库。我想你忘了添加 include $(CLEAR_VARS)之前LOCAL_MODULE := receiptrecognizer .

希望对你有用。