在Android JUnit测试中加载本机库 [英] Loading a native library in an Android JUnit test

问题描述

我使用 ndk-build 生成了一个本机库，我可以在我的Android应用程序中加载和使用它。但是，我想针对我的应用程序的这一部分编写一些测试。

I've generated a native library using ndk-build which I'm able to load and use with in my Android application. However, I want to write some tests against this part of my app.

在我的测试中调用本机函数时，我收到此异常消息：

When calling the native function in my tests, I recieve this exception message:

java.lang.UnsatisfiedLinkError: no process in java.library.path

...其中进程是我要导入的本机库，名为 libprocess.so 。

...where process is my native library to import, named libprocess.so.

我正在使用Roboelectric进行测试，并使用 RobolectricTestRunner 运行此特定的测试如果它有所作为。

I'm using Roboelectric for my tests, and running this particular one with the RobolectricTestRunner, if it makes a difference.

如何让我的测试项目看到本地库？

How can I get my test project to 'see' the native library?

编辑：
我正在我的应用中加载库，如下所示：

I'm loading the library in my app like so:

static {
    System.loadLibrary("process");
}
public static native int[] process(double[][] data);

调用 Process.process（array）工作原理应用程序正常（库已加载），但在测试中运行时失败，但上面给出的例外情况。

calling Process.process(array) works fine in the app (the library is loaded), but fails when run from the tests with the exception given above.

编辑2：
如果我将 -Djava.library.path =< libprocess.so>目录设置为VM参数，然后：

Edit 2: If I set -Djava.library.path="<the directory of libprocess.so>" as a VM argument, then:

System.out.println(System.getProperty("java.library.path"));

确实显示我设置的路径，但我仍然得到相同的异常。我将目录设置为：

does show the path I set, but I still get the same exception. I'm setting the directory as:

<project-name>/libs/x86

...但作为绝对路径。

...but as an absolute path.

推荐答案

我已经切换到默认测试样式（使用ActivityUnitTestCase而不是RoboElectric），它现在运行正常。遗憾的是我必须牺牲测试运行的速度，但在模拟器上运行测试实际上是可行的。您还可以为JNI类创建一个影子类，详见此处：

I've switched to the default testing style (using ActivityUnitTestCase instead of RoboElectric) and it's now running fine. It's a shame I have to sacrifice the speed of test running, but running the tests on the emulator actually works. You could also create a shadow class for the JNI class, as detailed here:

Robolectric坦克在加载JNI库的Application对象上。我可以获得一种解决方法吗？

也许为我的机器编译库可能会有效，但我不能再花费更多时间了。

Perhaps compiling the library for my machine would have worked, but I couldn't spend any more time on it.

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