如何在junit 5单元测试中模拟@Autowired对象？
如何在junit 5单元测试中模拟@Autowired对象？
提问于 2020-03-19 07:11:47
我正在使用junit 5对我的spring引导服务类进行单元测试。在服务类中，我是用于在其他类中调用方法的自动对象。在测试用例中，@Mock并不是为@Autowired类创建对象。这是我的密码。
我的服务班：
@Service
public class BarcodeReaderService {
@Autowired
ImageProcessor imageProcessor;
public String dummy(String name) {
System.out.println("function call"); //print success
return imageProcessor.dummy(name); //Null pointer Exception
}
}我的组件类：
@Component
public class ImageProcessor {
public String dummy(String name) {
// TODO Auto-generated method stub
System.out.println("function call ImageProcessor"); //Not coming to this line
return name;
}
}我的单元测试课：
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.junit.jupiter.MockitoExtension;
import com.inslab.reader.barcodereader.imageprocessing.ImageProcessor;
import com.inslab.reader.barcodereader.service.BarcodeReaderService;
@ExtendWith(MockitoExtension.class)
public class BarcodeReaderServiceTest {
@InjectMocks
BarcodeReaderService barcodeReaderService;
@Mock
ImageProcessor imageProcessor;
@Test
void testDummy() {
Mockito.when(imageProcessor.dummy("name")).thenReturn("name");
String name = barcodeReaderService.dummy("name");
Assertions.assertEquals("name", name);
}
}pom.xml文件：
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.4.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<groupId>com.inslab.reader</groupId>
<artifactId>barcodereader</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>barcodereader</name>
<packaging>jar</packaging>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</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>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
<exclusion>
<groupId>com.vaadin.external.google</groupId>
<artifactId>android-json</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>在运行这个测试时，我得到了imageProcessor.dummy(名称)中的空指针异常；
回答 3
Stack Overflow用户
回答已采纳
发布于 2020-03-21 17:51:42
我在上课一开始就添加了@SpringBootTest。啊，真灵。确保您的导入对junit 5是正确的。这里是我的代码，
package com.inslab.reader;
import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.mock.web.MockMultipartFile;
import com.google.zxing.Result;
import com.inslab.reader.ImageProcessor;
import com.inslab.reader.IReader;
@SpringBootTest
class BarcodeReaderServiceTest {
@InjectMocks
BarcodeReaderService barcodeReaderService;
@Mock
ImageProcessor imageProcessor;
@BeforeEach //instead of @Before have to use @BeforeEach in junit5
public void setup() {
MockitoAnnotations.initMocks(this);
}
@Test
void testDummy() {
Mockito.when(imageProcessor.dummy("name")).thenReturn("name");
String name = barcodeReaderService.dummy("name");
Assertions.assertEquals("name", name);
}
}Stack Overflow用户
发布于 2020-03-19 07:27:13
您必须为测试注册MocktioExtension，如下所示：
@ExtendWith(MockitoExtension.class)
public class BarcodeReaderServiceTest {
@InjectMocks
BarcodeReaderService barcodeReaderService;
@Mock
ImageProcessor imageProcessor;
@Test
void testDummy() {
when(imageProcessor.dummy("name")).thenReturn("YOUR_OUTCOME");
String name = barcodeReaderService.dummy("name");
Assertions.assertEquals("YOUR_OUTCOME", name);
}
}此外，不要在测试中使用new来创建被测试类的实例，而是使用字段变量barcodeReaderService。当您使用Mockito时，您还必须指定Mock的行为，否则它将始终返回null。
Stack Overflow用户
发布于 2021-09-30 07:52:49
在测试类中使用@InjectMocks作为您的服务类，您的服务类中的所有其他@Autowired都应该是@Mock在测试类中
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/60752423
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