使用Mockito模拟类时出现NullPointerException

Question

While trying to test a method with Junit and Mockito2 , I am getting NullPointerException .

import static org.mockito.Mockito.*;
import static org.junit.Assert.*;
    @Test
    public void testMethod(){
    Application app=mock(Application.class);//line 2
    assertEquals(true,app.methodToTest());
    }

I am getting a NullPointerException on line 2 . I am using junit 4.8.1 and mockito-all 2.0.2-beta .The Application class has constructor with Argument JSONObject(org.json.JSONObject)

Answer 1

Before writing any test cases for methods you have to initialized MockitoAnnotations.initMocks eg:

protected boolean mockInitialized = false;
@Before
public void setUp() {
   if (!mockInitialized) {
      MockitoAnnotations.initMocks(this);
      mockInitialized = true;
   }
}

Hope this may resolve your issue. or provide the actual class code for which you are trying to write test cases.

Answer 2

As I was thinking , the nullpointerexception was due to mismatches in dependencies . The mentioned issue got resolved by using below dependencies

<!-- https://mvnrepository.com/artifact/junit/junit -->
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.12</version>
    <scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.powermock/powermock-module-junit4-legacy -->
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-module-junit4-legacy</artifactId>
    <version>1.6.4</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.powermock/powermock-module-junit4 -->
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-module-junit4</artifactId>
    <version>1.6.4</version>
    <scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.powermock/powermock-module-junit4-legacy -->
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-module-junit4-legacy</artifactId>
    <version>1.7.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.powermock/powermock-api-mockito2 -->
<dependency>
    <groupId>org.powermock</groupId>
    <artifactId>powermock-api-mockito2</artifactId>
    <version>1.7.1</version>
    <scope>test</scope>
</dependency>