Mockito Test With java.lang.NullPointerException - spring-boot

Question

I created a Spring Boot 2 application with Junit 4 and Mockito. When I test some method. there will be an exception like this :
java.lang.NullPointerException
at com.xxx.service.SurveyServiceTest.getSurveyList(SurveyServiceTest.java:41)
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.InvokeMethod.evaluate(InvokeMethod.java:17)
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.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:79)
at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:85)
at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Here is my test code
#RunWith(MockitoJUnitRunner.class)
public class SurveyServiceTest {
#MockBean
SurveyRepository repostory;
#InjectMocks
SurveyService service;
#Test
public void getSurveyList() {
when(repostory.findAll()).thenReturn(Arrays.asList( new Survey(new Long(1),101,"Test1"),
new Survey(new Long(2),102,"Test2") ));
assertTrue(service.getSurveyList().size() >0);
}
}
SuveryService.java
#Service
public class SurveyService {
#Autowired
private SurveyRepository repostory;
public List<Survey> getSurveyList() {
return repostory.findAll();
}
public Optional<Survey> getSurveyById() {
return repostory.findById((long) 1);
}
public Survey add() {
Survey survey = new Survey();
survey.setSurveyID(1);
survey.setSurveyContent("ddddd");
return repostory.save(survey);
}
public Survey update() {
Survey survey = new Survey();
survey.setSurveyID(1);
survey.setSurveyContent("gggg1");
return repostory.save(survey);
}
public void delete() {
repostory.deleteById((long) 1);
}
public List<Survey> findBySurveyContent() {
return repostory.findBySurveyContent("gggg1");
}
public int updateBySurveyId(){
return repostory.updateBySurveyId("hhhhhh", 1);
}
}
SurveyRepository.java
public interface SurveyRepository extends JpaRepository<Survey, Long> {
public List<Survey> findBySurveyContent(String surveyContent);
#Query(value = "update XXX_DATA.SURVEYS set SURVEYCONTENT=? where SURVEYID=?",nativeQuery = true)
#Modifying
#Transactional
public int updateBySurveyId(String surveyContent,int surveyId);
}
Survey.java
#Entity
#Table(name="SURVEYS", schema="XXX_DATA")
public class Survey{
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "ID")
private Long id;
#Column(name = "SURVEYID")
private Integer surveyID;
#Column(name = "SURVEYCONTENT")
private String surveyContent;
public Survey(){
}
public Survey(Long id,Integer surveyID,String surveyContent){
this.id = id;
this.surveyID = surveyID;
this.surveyContent = surveyContent;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Integer getSurveyID() {
return surveyID;
}
public void setSurveyID(Integer surveyID) {
this.surveyID = surveyID;
}
public String getSurveyContent() {
return surveyContent;
}
public void setSurveyContent(String surveyContent) {
this.surveyContent = surveyContent;
}
}
POM.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.xxx.test</groupId>
<artifactId>xxx-service</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>xxx-service</name>
<description>XXX Service</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<repositories>
<repository>
<id>maven-repository</id>
<url>file:///${project.basedir}/maven-repository</url>
</repository>
<repository>
<id>com.ibm.db2.jcc</id>
<url>https://artifacts.alfresco.com/nexus/content/repositories/public/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.ibm.db2.jcc</groupId>
<artifactId>db2jcc4</artifactId>
<version>10.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.security</groupId>
<artifactId>spring-security-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.ibm.watson.developer_cloud</groupId>
<artifactId>java-sdk</artifactId>
<version>5.1.1</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
<dependency>
<groupId>com.ibm.swat.password</groupId>
<artifactId>cwa2</artifactId>
<version>2.3.5.3</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.15</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml-schemas</artifactId>
<version>3.15</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>
I referenced this article Mockito NullPointerException, but the issue still existed.
Any help will be appcirated.

Answer 1

#MockBean is a Spring annotation, which only has an effect if you create a Spring boot integration test, run with the SpringRunner.
You have a unit test here, run with MockitoJUnitRunner, and you just want Mockito to create your mock repository. The correct annotation is #Mock.

Answer 2

You sould do that :
#RunWith(MockitoJUnitRunner.class)
public class SurveyServiceTest {
#Mock// and not MockBean
SurveyRepository repostory;
#InjectMocks
SurveyService service;
#Test
public void getSurveyList() {
when(repostory.findAll()).thenReturn(Arrays.asList( new Survey(new Long(1),101,"Test1"),
new Survey(new Long(2),102,"Test2") ));
assertTrue(service.getSurveyList().size() >0);
}
}

Answer 3

To extend the above answers, Since #MockBean is a spring annotation, you can use the below code as an alternative. #MockBean is used to add mock objects to the Spring application context. The mock will replace any existing bean of the same type in the application context. So it is a kind of functionality of both #Mock as well as #InjectMock. Also if you not following JUnit 5 you require to replace #RunWith(SpringRunner.class) with #ExtendWith(SpringExtention.class)
#RunWith(SpringRunner.class)
public class SurveyServiceTest {
#MockBean
SurveyRepository repostory;
#Test
public void getSurveyList() {
when(repostory.findAll()).thenReturn(Arrays.asList( new Survey(new
Long(1),101,"Test1"),
new Survey(new Long(2),102,"Test2") ));
assertTrue(service.getSurveyList().size() >0);
}
}