最近在项目中将Rxjava升级到Rxjava2之后，对之前的P、M(项目是基于MVP结构)层进行单元测试的时候，出现了如下的问题：
Android RxJava 2 JUnit test - getMainLooper in android.os.Looper not mocked RuntimeException
java.lang.ExceptionInInitializerError
at io.reactivex.android.schedulers.AndroidSchedulers$1.call(AndroidSchedulers.java:35)
at io.reactivex.android.schedulers.AndroidSchedulers$1.call(AndroidSchedulers.java:33)
at io.reactivex.android.plugins.RxAndroidPlugins.callRequireNonNull(RxAndroidPlugins.java:70)
at io.reactivex.android.plugins.RxAndroidPlugins.initMainThreadScheduler(RxAndroidPlugins.java:40)
at io.reactivex.android.schedulers.AndroidSchedulers.<clinit>(AndroidSchedulers.java:32)
…
Caused by: java.lang.RuntimeException: Method getMainLooper in android.os.Looper not mocked. See http://g.co/androidstudio/not-mocked for details.
at android.os.Looper.getMainLooper(Looper.java)
at io.reactivex.android.schedulers.AndroidSchedulers$MainHolder.<clinit>(AndroidSchedulers.java:29)
...
java.lang.NoClassDefFoundError: Could not initialize class io.reactivex.android.schedulers.AndroidSchedulers
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
出现这个问题的原因是：AndroidSchedulers.mainThread返回的是LooperScheduler的一个实例，但是LooperScheduler依赖于Android，我们在纯Java的单元测试中是无法使用它的。找到了问题的原因解决起来就容易多了。
我们需要在单元测试运行之前，初始化RxAndroidPlugins让它返回一个我们指定的不依赖于Android的Scheduler。下面给出两种解决方案。
方案一：
在@BeforeClass里面初始化Scheduler:
@BeforeClass
public static void setUpRxSchedulers(){
final Scheduler immediate = new Scheduler() {
@Override
public Disposable scheduleDirect(@NonNull Runnable run, long delay, @NonNull TimeUnit unit) {
return super.scheduleDirect(run, 0, unit);
}
@Override
public Worker createWorker() {
return new ExecutorScheduler.ExecutorWorker(new Executor() {
@Override
public void execute(@android.support.annotation.NonNull Runnable command) {
command.run();
}
});
}
};
RxJavaPlugins.setInitIoSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxJavaPlugins.setInitComputationSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxJavaPlugins.setInitNewThreadSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxJavaPlugins.setInitSingleSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxAndroidPlugins.setInitMainThreadSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
}
这样做虽然可以解决问题，但是你需要在每个测试类里面都要添加这样的代码，非常麻烦，有没有简单一点的办法呢？当然是有的，我们可以自定义一个TestRule，在需要的地方直接调用就行了。
方案二：
自定义一个RxSchedulersOverrideRule让它实现TestRule:
public class RxSchedulersOverrideRule implements TestRule {
private Scheduler immediate = new Scheduler() {
@Override
public Disposable scheduleDirect(@NonNull Runnable run, long delay, @NonNull TimeUnit unit) {
return super.scheduleDirect(run, 0, unit);
}
@Override
public Worker createWorker() {
return new ExecutorScheduler.ExecutorWorker(new Executor() {
@Override
public void execute(@android.support.annotation.NonNull Runnable command) {
command.run();
}
});
}
};
@Override
public Statement apply(final Statement base, Description description) {
return new Statement() {
@Override
public void evaluate() throws Throwable {
RxJavaPlugins.setInitIoSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxJavaPlugins.setInitComputationSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxJavaPlugins.setInitNewThreadSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxJavaPlugins.setInitSingleSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
RxAndroidPlugins.setInitMainThreadSchedulerHandler(new Function<Callable<Scheduler>, Scheduler>() {
@Override
public Scheduler apply(@NonNull Callable<Scheduler> schedulerCallable) throws Exception {
return immediate;
}
});
try {
base.evaluate();
}finally {
RxJavaPlugins.reset();
RxAndroidPlugins.reset();
}
}
};
}
}
在需要的地方直接像下面这样调用即可：
@ClassRule
public static RxSchedulersOverrideRule sSchedulersOverrideRule = new RxSchedulersOverrideRule();
网友评论