java.lang.Exception：自定义运行器类AndroidJUnit4应该有一个带有签名AndroidJUnit4的公共构造函数(Class testClass)

gradle看起来像：

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"

    defaultConfig {
        applicationId "com.google.developer.taskmaker"
        minSdkVersion 19
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

configurations.all {
    resolutionStrategy {
        force 'com.android.support:support-annotations:25.2.0'
    }
}


dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:25.2.0'
    compile 'com.android.support:recyclerview-v7:25.2.0'
    compile 'com.android.support:design:25.2.0'
    compile 'com.android.support:preference-v7:25.2.0'
    debugCompile 'im.dino:dbinspector:3.4.1@aar'
    // Android JUnit Runner
    compile 'com.google.android.gms:play-services-appindexing:8.4.0'
    // Android runner and rules support

    // add this for intent mocking support
    androidTestCompile 'com.android.support.test.espresso:espresso-intents:2.2.2'

    // add this for webview testing support
    androidTestCompile 'com.android.support.test.espresso:espresso-web:2.2.2'
    compile 'com.android.support.test:runner:0.5'
    compile 'com.android.support.test:rules:0.5'
    compile 'com.android.support.test.espresso:espresso-core:2.2.2'
}

单元测试用例看起来像

@RunWith(AndroidJUnit4.class)
public class TestClass {

    @Rule
    public ActivityTestRule<MainActivity> mActivityRule =
            new ActivityTestRule<>(MainActivity.class);

    @Test
    public void buttonClick(){
        onView(withId(R.id.fab)).perform(click()).check(matches(isDisplayed()));
    }

}

错误消息如下所示：

java.lang.Exception: Custom runner class AndroidJUnit4 should have a public constructor with signature AndroidJUnit4(Class testClass)

    at org.junit.runners.model.InitializationError.<init>(InitializationError.java:38)
    at org.junit.internal.builders.AnnotatedBuilder.buildRunner(AnnotatedBuilder.java:111)
    at org.junit.internal.builders.AnnotatedBuilder.runnerForClass(AnnotatedBuilder.java:86)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:26)
    at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:59)
    at org.junit.runners.model.RunnerBuilder.runners(RunnerBuilder.java:101)
    at org.junit.runners.model.RunnerBuilder.runners(RunnerBuilder.java:87)
    at com.intellij.junit4.JUnit46ClassesRequestBuilder.collectWrappedRunners(JUnit46ClassesRequestBuilder.java:90)
    at com.intellij.junit4.JUnit46ClassesRequestBuilder.getClassesRequest(JUnit46ClassesRequestBuilder.java:51)
    at com.intellij.junit4.JUnit4TestRunnerUtil.buildRequest(JUnit4TestRunnerUtil.java:91)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:95)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:234)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:74)
    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:497)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)


Process finished with exit code -1

我已经检查了其他答案,但没有得到解决方案.请告诉我哪里出错了.运行此代码时,我收到错误

解决方法:

原因1：将测试放在错误的文件夹中

通过在Android Studio中使用默认模板创建一个新的Application并将自动生成的ExampleInstrumentedTest从androidTest文件夹复制到test文件夹,可以复制此错误：

这是错误的样子：

请注意,为了复制问题,您还必须错误地将依赖项添加到模块级build.gradle：

原因2：测试配置错误

本地单元测试和仪表测试具有不同的运行配置.如果单击下面的编辑配置：

您应该在Android仪器测试下看到您的仪器化测试,并在Android JUnit下看到您的本地单元测试,如下图所示：

对于Android Instrumented Tests,配置应如下所示：

对于Android JUnit：

运行测试时,Android Studio将为您创建运行配置.如果运行配置的类别错误,请检查您的测试和androidTest文件夹是否正确,然后您可以从编辑配置中删除运行配置并再次运行测试.如果您已正确设置,Android Studio将使用正确类型的运行配置.

说明

Android中有两种类型的测试：

>仪器化测试
>本地单元测试

仪器化测试

仪表测试是旨在在手机或仿真器上运行的测试.这些是需要访问Android库的全功能部分的测试(例如真实的Context).这些需要进入androidTest文件夹,并且这些测试的依赖项(例如,Espresso,com.android.support.test.rules：0.5)将在build.gradle中以androidTestCompile为前缀.

这是一个示例检测测试：

import android.content.Context;
import android.support.test.InstrumentationRegistry;
import android.support.test.runner.AndroidJUnit4;

import org.junit.Test;
import org.junit.runner.RunWith;

import static org.junit.Assert.assertEquals;

/**
 * Instrumentation test, which will execute on an Android device.
 *
 * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
 */
@RunWith(AndroidJUnit4.class)
public class ExampleInstrumentedTest {
    @Test
    public void useAppContext() throws Exception {
        // Context of the app under test.
        Context appContext = InstrumentationRegistry.getTargetContext();

        assertEquals("com.gyaltsab.myapplication", appContext.getPackageName());
    }
}

本地单元测试

本地单元测试是可以在IDE中运行的测试.它们通常不依赖于标准JVM上不可用的Android库的任何部分(例如,它们不依赖于上下文).这些依赖项将在build.gradle的testCompile部分中进行.

这是一个示例单元测试：

import org.junit.Test;

import static org.junit.Assert.*;

/**
 * Example local unit test, which will execute on the development machine (host).
 *
 * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
 */
public class ExampleUnitTest {
    @Test
    public void addition_isCorrect() throws Exception {
        assertEquals(4, 2 + 2);
    }
}

请注意,本地单元测试不需要在类声明中使用@RunWith(AndroidJUnit4.class)注释.有关更完整的说明,请参阅the official docs.

标签：android,android-espresso
来源： https://codeday.me/bug/20191006/1860302.html