android - Gradle 实验性 JNI OpenCv arm 64-v8a 链接器错误

Question

我有一个使用 opencv android sdk 的项目，为了加快速度，我决定用 C++ 实现一些功能。

无论如何，我正在使用 gradle 实验性插件 0.4.0 以及何时为 arm64-v8a 构建，链接器告诉我它无法在 jniLibs 文件夹中找到库。尝试了许多不同的变体，我相信路径是正确的(使用 cd 在终端上检查)

这是我的 app.gradle:

apply plugin: 'com.android.model.application' model{



android {

    compileSdkVersion = 23
    buildToolsVersion = "23.0.2"
   /* sourceSets.main {
        jniLibs.srcDir 'src/main/jniLibs' //set libs as .so's location instead of jni
        jni.srcDirs = [] //disable automatic ndk-build call with auto-generated Android.mk file
    }*/
    defaultConfig.with {
        applicationId = "com.sketchcamera.camera"
        minSdkVersion.apiLevel = 15
        targetSdkVersion.apiLevel = 23
        versionCode = 105
        versionName = "1.05"
    }


}


android.buildTypes {
    release {
        minifyEnabled = false
        proguardFiles.add(file('proguard-android.txt'))
        //proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        //jniDebuggable = true
        //  signingConfig signingConfigs.release
    }
    debug {
        //jniDebuggable = true
    }
}
android.productFlavors {
    create("AArch-64") {
        ndk.with{
            abiFilters.add("arm64-v8a")

            File curDir = file('./')
            curDir = file(curDir.absolutePath)
            String libsDir = curDir.absolutePath + "/src/main/jniLibs/arm64-v8a/"

            ldLibs.add(libsDir + "libopencv_core.a")
            ldLibs.add(libsDir + "libopencv_highgui.a")
            ldLibs.add(libsDir + "libopencv_imgproc.a")
            ldLibs.add(libsDir + "libopencv_java3.so")
            ldLibs.add(libsDir + "libopencv_ml.a")

        }
    }
    create("arm") {
        ndk.with{
            abiFilters.add("armeabi")

            File curDir = file('./')
            curDir = file(curDir.absolutePath)
            String libsDir = curDir.absolutePath + "/src/main/jniLibs/armeabi/"

            ldLibs.add(libsDir + "libopencv_core.a")
            ldLibs.add(libsDir + "libopencv_highgui.a")
            ldLibs.add(libsDir + "libopencv_imgproc.a")
            ldLibs.add(libsDir + "libopencv_java3.so")
            ldLibs.add(libsDir + "libopencv_ml.a")

        }
    }
    create("armv7") {
        ndk.with {
            abiFilters.add("armeabi-v7a")

            File curDir = file('./')
            curDir = file(curDir.absolutePath)
            String libsDir = curDir.absolutePath + "/src/main/jniLibs/armeabi-v7a/"
            ldLibs.add(libsDir + "libopencv_core.a")
            ldLibs.add(libsDir + "libopencv_highgui.a")
            ldLibs.add(libsDir + "libopencv_imgproc.a")
            ldLibs.add(libsDir + "libopencv_java3.so")
            ldLibs.add(libsDir + "libopencv_ml.a")
            ldLibs.add(libsDir + "libopencv_ts.a")

        }
    }
}

android.ndk {
    moduleName = "opencv_fast_processing"
    cppFlags.add("-std=c++11")
    cppFlags.add("-fexceptions")
    cppFlags.add("-I${file("/home/onur/Masaüstü/Home/OpenCV-android-sdk/sdk/native/jni/include")}".toString())
    ldLibs.addAll(["android", "EGL", "GLESv2", "dl", "log", "z"])
    stl = "gnustl_shared"
}
// android.useLibrary = 'org.apache.http.legacy'

如果我使用 arm7 或 arm，一切都很好，但如果使用 arm64-v8a 编译，链接器会给出此错误:

/home/onur/Android/android-ndk-r11c/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64/bin/../lib/gcc/aarch64-linux-android/4.9/../../../../aarch64-linux-android/bin/ld: cannot find -l/home/onur/AndroidStudioProjects/SketchCamera/app/src/main/jniLibs/arm64-v8a/libopencv_core.a

其他文件也有同样的错误..正如我之前所说，我确信路径是正确的，但不知道/home 前面的 -l 是什么(对 C 和 gnu 没有太多经验)

我是 JNI 的新手，很可能做了一些愚蠢的事情。感谢您的帮助

Answer 1

我在这里遇到了同样的问题，但使用了 libcrypto (OpenSSL)。我设法通过更改我的 build.gradle 文件来解决它。而不是使用 productFlavors 我改为 repositores 部分作为以下示例:

删除这段代码:

abis {
        create("x86") {
            ldLibs.add("${file("src/main/jniLibs/x86/libcrypto.so")}".toString())
        }
        create("x86_64") {
            ldLibs.add("${file("src/main/jniLibs/x86_64/libcrypto.so")}".toString())
        }
        create("armeabi-v7a") {
            ldLibs.add("${file("src/main/jniLibs/armeabi-v7a/libcrypto.so")}".toString())
        }
        create("arm64-v8a") {
            ldLibs.add("${file("src/main/jniLibs/armeabi-v7a/libcrypto.so")}".toString())
        }
    }

然后添加这个:

repositories {
    prebuilt(PrebuiltLibraries) {
        prebuiltSharedlib {
            binaries.withType(SharedLibraryBinary) {
                sharedLibraryFile = file("src/main/jniLibs/${targetPlatform.getName()}/libcrypto.so")
            }
        }
    }
}
android.sources {
    main {
        jni {
            dependencies {
                library "prebuiltSharedlib"
            }
        }
    }
}

最后在 ndk 部分设置 ABI 过滤器:

abiFilters.addAll(["armeabi-v7a", "arm64-v8a", "x86", "x86_64"])

希望对您有所帮助。