I have an error when I run the test as below:
org.mockito.exceptions.base.MockitoException:
Mockito cannot mock this class: class com.bignerdranch.android.beatbox.BeatBox.
Mockito can only mock non-private & non-final classes.
If you’re not sure why you’re getting this error, please report to the mailing list.
Java : 1.8
JVM vendor name : JetBrains s.r.o
JVM vendor version : 25.112-b06
JVM name : OpenJDK 64-Bit Server VM
JVM version : 1.8.0_112-release-b06
JVM info : mixed mode
OS name : Windows 10
OS version : 10.0
Underlying exception : java.lang.IllegalArgumentException: Could not create type
at com.bignerdranch.android.beatbox.SoundViewModelTest.setUp(SoundViewModelTest.java:20)
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)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:117)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:42)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:262)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:84)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147)
Caused by: java.lang.IllegalArgumentException: Could not create type
at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:140)
at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:346)
at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:161)
at net.bytebuddy.TypeCache$WithInlineExpunction.findOrInsert(TypeCache.java:355)
at org.mockito.internal.creation.bytebuddy.TypeCachingBytecodeGenerator.mockClass(TypeCachingBytecodeGenerator.java:32)
at org.mockito.internal.creation.bytebuddy.SubclassByteBuddyMockMaker.createMockType(SubclassByteBuddyMockMaker.java:71)
at org.mockito.internal.creation.bytebuddy.SubclassByteBuddyMockMaker.createMock(SubclassByteBuddyMockMaker.java:42)
at org.mockito.internal.creation.bytebuddy.ByteBuddyMockMaker.createMock(ByteBuddyMockMaker.java:25)
at org.mockito.internal.util.MockUtil.createMock(MockUtil.java:35)
at org.mockito.internal.MockitoCore.mock(MockitoCore.java:65)
at org.mockito.Mockito.mock(Mockito.java:1821)
at org.mockito.Mockito.mock(Mockito.java:1734)
… 36 more
Caused by: java.lang.NoClassDefFoundError: android/content/Context
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
at java.lang.Class.getDeclaredConstructors(Class.java:2020)
at net.bytebuddy.description.method.MethodList$ForLoadedMethods.(MethodList.java:90)
at net.bytebuddy.description.type.TypeDescription$ForLoadedType.getDeclaredMethods(TypeDescription.java:7232)
at net.bytebuddy.description.type.TypeDescription$Generic$OfNonGenericType.getDeclaredMethods(TypeDescription.java:3349)
at net.bytebuddy.description.type.TypeDescription$Generic$LazyProjection.getDeclaredMethods(TypeDescription.java:5242)
at net.bytebuddy.dynamic.scaffold.subclass.ConstructorStrategy$Default$5.doExtractConstructors(ConstructorStrategy.java:157)
at net.bytebuddy.dynamic.scaffold.subclass.ConstructorStrategy$Default.extractConstructors(ConstructorStrategy.java:176)
at net.bytebuddy.dynamic.scaffold.subclass.SubclassDynamicTypeBuilder.applyConstructorStrategy(SubclassDynamicTypeBuilder.java:185)
at net.bytebuddy.dynamic.scaffold.subclass.SubclassDynamicTypeBuilder.make(SubclassDynamicTypeBuilder.java:162)
at net.bytebuddy.dynamic.scaffold.subclass.SubclassDynamicTypeBuilder.make(SubclassDynamicTypeBuilder.java:155)
at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase.make(DynamicType.java:2639)
at net.bytebuddy.dynamic.DynamicType$Builder$AbstractBase$Delegator.make(DynamicType.java:2741)
at org.mockito.internal.creation.bytebuddy.SubclassBytecodeGenerator.mockClass(SubclassBytecodeGenerator.java:114)
at org.mockito.internal.creation.bytebuddy.TypeCachingBytecodeGenerator$1.call(TypeCachingBytecodeGenerator.java:37)
at org.mockito.internal.creation.bytebuddy.TypeCachingBytecodeGenerator$1.call(TypeCachingBytecodeGenerator.java:34)
at net.bytebuddy.TypeCache.findOrInsert(TypeCache.java:138)
… 47 more
Caused by: java.lang.ClassNotFoundException: android.content.Context
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
… 65 more
Process finished with exit code -1
, and classes:
SoundViewModelTest.java
package com.bignerdranch.android.beatbox;
import org.junit.Before;
import org.junit.Test;
import static org.hamcrest.core.Is.is;
import static org.junit.Assert.*;
import static org.mockito.Mockito.mock;
/**
* Created by behin on 10/15/2017.
*/
public class SoundViewModelTest {
private BeatBox mBeatBox;
private Sound mSound;
private SoundViewModel mSubject;
@Before
public void setUp() throws Exception {
mBeatBox = mock(BeatBox.class);
mSound = new Sound("assetPath");
mSubject = new SoundViewModel(mBeatBox);
mSubject.setSound(mSound);
}
@Test
public void exposesSoundNameAsTitle() {
assertThat(mSubject.getTitle(), is(mSound.getName()));
}
}
BeatBox.java
package com.bignerdranch.android.beatbox;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.content.res.AssetManager;
import android.media.AudioManager;
import android.media.SoundPool;
import android.util.Log;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* Created by behin on 10/11/2017.
*/
public class BeatBox {
private static final String TAG = "BeatBox";
private static final String SOUNDS_FOLDER = "sample_sounds";
private static final int MAX_SOUNDS = 5;
private AssetManager mAssets;
private List<Sound> mSounds = new ArrayList<>();
private SoundPool mSoundPool;
public BeatBox(Context context) {
mAssets = context.getAssets();
// This old constructor is deprecated but needed for compatibility
mSoundPool = new SoundPool(MAX_SOUNDS, AudioManager.STREAM_MUSIC, 0);
loadSounds();
}
public void play(Sound sound) {
Integer soundId = sound.getSoundId();
if(soundId == null) {
return;
}
mSoundPool.play(soundId, 1.0f, 1.0f, 1, 0, 1.0f);
}
private void loadSounds() {
String[] soundNames = new String[0];
try {
soundNames = mAssets.list(SOUNDS_FOLDER);
Log.i(TAG, "Found " + soundNames.length + " sounds");
} catch (IOException e) {
Log.e(TAG, "Could not list assets", e);
}
for (String filename : soundNames) {
try {
String assetPath = SOUNDS_FOLDER + "/" + filename;
Sound sound = new Sound(assetPath);
load(sound);
mSounds.add(sound);
} catch (IOException ieo) {
Log.e(TAG, "Could not load sound " + filename, ieo);
}
}
}
private void load(Sound sound) throws IOException {
AssetFileDescriptor afd = mAssets.openFd(sound.getAssetPath());
int soundId = mSoundPool.load(afd, 1);
sound.setSoundId(soundId);
}
public List<Sound> getSounds() {
return mSounds;
}
}
I tried several solutions from the webs then I rewrite the app and check all codes but the problem is not solved 
.
please help! 
Thanks!
Edit:
I forget to include build.gradle:
BeatBox\app\build.gradle
apply plugin: 'com.android.application'
android {
compileSdkVersion 26
buildToolsVersion "26.0.0"
defaultConfig {
applicationId "com.bignerdranch.android.beatbox"
minSdkVersion 19
targetSdkVersion 26
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
dataBinding {
enabled = true
}
}
dependencies {
compile fileTree(include: ['*.jar'], dir: 'libs')
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:26.+'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
testCompile 'junit:junit:4.12'
compile 'com.android.support:recyclerview-v7:26.0.0-alpha1'
testCompile 'org.mockito:mockito-core:2.11.0'
testCompile 'org.hamcrest:hamcrest-junit:2.0.0.0'
}