如何获取路径到lib文件夹中已安装包

Question

共享库.so文件被放置在LIB / armeabi在apk文件。

我已经安装后读取库被提取到/数据/数据/ application_package / lib中

我怎样才能得到我的在运行时应用到这个目录确切的路径？ 由应用这个目录可读？或者仅仅executeable允许访问？ 如果是可读的 - 这是用于复制保护的应用仍然是正确的。

Answer 1

您可以得到确切的路径：

String libraryPath = getContext().getApplicationInfo().dataDir + "/lib";

在目录及其文件是可读由应用程序。

UNIX权限被设定为rwxr-x--x。所以与应用 相同的基团可以读取文件。

Answer 2

在API级别9

getContext().getApplicationInfo().nativeLibraryDir;

Answer 3

String libpath = getApplicationInfo().nativeLibraryDir;

Class用于：导入android.content.pm.ApplicationInfo;

Answer 4

如果您使用的是原生的活动和C ++：

void ANativeActivity_onCreate(ANativeActivity* app, void*, size_t) {
    const jclass contextClass = app->env->GetObjectClass(app->clazz);
    const jmethodID getApplicationContextMethod =
        app->env->GetMethodID(contextClass, "getApplicationContext", "()Landroid/content/Context;");
    const jobject contextObject =
        app->env->CallObjectMethod(app->clazz, getApplicationContextMethod);
    const jmethodID getApplicationInfoMethod = app->env->GetMethodID(
        contextClass, "getApplicationInfo", "()Landroid/content/pm/ApplicationInfo;");
    const jobject applicationInfoObject =
        app->env->CallObjectMethod(contextObject, getApplicationInfoMethod);
    const jfieldID nativeLibraryDirField = app->env->GetFieldID(
        app->env->GetObjectClass(applicationInfoObject), "nativeLibraryDir", "Ljava/lang/String;");
    const jobject nativeLibraryDirObject =
        app->env->GetObjectField(applicationInfoObject, nativeLibraryDirField);
    const jmethodID getBytesMethod = app->env->GetMethodID(
        app->env->GetObjectClass(nativeLibraryDirObject), "getBytes", "(Ljava/lang/String;)[B");
    const auto bytesObject = static_cast<jbyteArray>(app->env->CallObjectMethod(
        nativeLibraryDirObject, getBytesMethod, app->env->NewStringUTF("UTF-8")));
    const size_t length = app->env->GetArrayLength(bytesObject);
    const jbyte* const bytes = app->env->GetByteArrayElements(bytesObject, nullptr);
    const std::string libDir(reinterpret_cast<const char*>(bytes), length);

Answer 5

String libraryPath = context.getFilesDir().getParentFile().getPath() + "/lib";

有关较好的相容性，使用下面的函数：

@TargetApi(Build.VERSION_CODES.GINGERBREAD)
public static String getLibraryDirectory(Context context) {
    int sdk_level = android.os.Build.VERSION.SDK_INT;

    if (sdk_level >= Build.VERSION_CODES.GINGERBREAD) {
        return context.getApplicationInfo().nativeLibraryDir;
    } 
    else if (sdk_level >= Build.VERSION_CODES.DONUT) {
        return context.getApplicationInfo().dataDir + "/lib";
    }

    return "/data/data/" + context.getPackageName() + "/lib";
}

Answer 6

也许一个设备支持不同CPU_ABIs，所以最好让nativeRootLibraryDir包含所有子lib目录：

public static String getNativeLibraryDirectory(Context context) {
    int sdk_level = android.os.Build.VERSION.SDK_INT;

    if (sdk_level >= Build.VERSION_CODES.GINGERBREAD) {
        try {
            String secondary = (String) ApplicationInfo.class.getField("nativeLibraryRootDir").get(context.getApplicationInfo());
            return secondary;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
    else if (sdk_level >= Build.VERSION_CODES.DONUT) {
        return context.getApplicationInfo().dataDir + "/lib";
    }

    return "/data/data/" + context.getPackageName() + "/lib";
}