近期有个项目采用了SpringBoot3 以及JUnit5进行单元测试，在此过程中一直提示Spring中依赖注入报错的问题，该问题的解决方案比较特殊，主要是升级maven-surefire-plugin的版本，故简单记录下。

问题描述

相关代码如下，主要基于UserMapperTest进行测试

import com.lucumt.app.AuthApplication;
import com.lucumt.app.model.SysUser;
import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

import static org.junit.jupiter.api.Assertions.assertFalse;

@Slf4j
@SpringBootTest(classes = AuthApplication.class)
public class UserMapperTest {

    @Resource
    private SysUserMapper userMapper;

    @BeforeAll
    public static void init(){
        System.setProperty("nacos.logging.default.config.enabled", "false");
    }

    @Test
    public void testSelectUser(){
        List<SysUser> userList = userMapper.selectList(null);
        userList.forEach(s->log.info(s.toString()));
        assertFalse(userList.isEmpty());
    }
}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.lucumt.app.model.SysUser;

public interface SysUserMapper extends BaseMapper<SysUser> {
}

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@EnableDiscoveryClient
@SpringBootApplication
@MapperScan("com.lucumt.app.mapper")
@SuppressWarnings("uncommentedmain")
public class AuthApplication {

    public static void main(String[] args) {
        System.setProperty("nacos.logging.default.config.enabled", "false");
        SpringApplication.run(AuthApplication.class);
    }
}

<?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.lucumt.app</groupId>
    <artifactId>auth</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>pom</packaging>
    <description>应用中心 - 权限与认证模块</description>
    <modules>
        <module>app</module>
        <module>common</module>
    </modules>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <spring.boot.version>3.2.12</spring.boot.version>
        <spring.cloud.version>2023.0.1</spring.cloud.version>
        <nacos.version>2023.0.1.0</nacos.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${spring.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <dependencies>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.15.4</version>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20220320</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.36</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>${maven.compiler.source}</source>
                    <target>${maven.compiler.target}</target>
                    <encoding>${project.encoding}</encoding>
                </configuration>
            </plugin>
            <!-- 持续集成时检查代码规范 -->
            <plugin>
                <groupId>org.sonarsource.scanner.maven</groupId>
                <artifactId>sonar-maven-plugin</artifactId>
                <version>3.6.0.1398</version>
            </plugin>
            <!-- 检查代码规范 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
                <version>3.1.2</version>
                <dependencies>
                    <dependency>
                        <groupId>com.puppycrawl.tools</groupId>
                        <artifactId>checkstyle</artifactId>
                        <version>8.41.1</version>
                    </dependency>
                </dependencies>
                <configuration>
                    <configLocation>style/checkStyle.xml</configLocation>
                    <encoding>UTF-8</encoding>
                    <consoleOutput>true</consoleOutput>
                    <failsOnError>true</failsOnError>
                    <linkXRef>false</linkXRef>
                </configuration>
                <executions>
                    <execution>
                        <id>validate</id>
                        <phase>validate</phase>
                        <goals>
                            <goal>check</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <!-- 上传jar包到仓库 -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <version>2.8.2</version>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>2.4.3</version>
                <configuration>
                    <encoding>utf-8</encoding>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>release</id>
            <url>https://mirrors.lucumt.com/repository/Maven-local</url>
        </repository>
    </repositories>

    <distributionManagement>
        <repository>
            <id>release</id>
            <url>https://mirrors.lucumt.com/repository/Maven-local</url>
        </repository>
    </distributionManagement>

</project>

<?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>
    <parent>
        <groupId>com.lucumt.app</groupId>
        <artifactId>auth</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <artifactId>auth-app</artifactId>

    <properties>
        <maven.compiler.source>21</maven.compiler.source>
        <maven.compiler.target>21</maven.compiler.target>
        <nacos.version>2023.0.1.0</nacos.version>
        <mysql.version>8.0.15</mysql.version>
        <mybatis-plus.version>3.5.5</mybatis-plus.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.lucumt.app</groupId>
            <artifactId>auth-common</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-bootstrap</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-log4j2</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>com.vaadin.external.google</groupId>
                    <artifactId>android-json</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
            <version>${nacos.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
            <version>${nacos.version}</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
            <version>${mybatis-plus.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <version>${spring.boot.version}</version>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

在Intellij Idea中直接运行该测试类，可运行成功

IDEA中直接运行成功

在控制台执行mvn clean compile test时，报如下所示的空指针错误

命令行中通过maven运行报错

解决方案

一开始自己主要通过Google搜索，主要找到回复1和回复2，但均未能解决报错问题。

咨询Deepseek后，其给出的解决方案如下，挨个对照检查，自己的项目中并没有违反相关约束。

错误原因 解决方案
缺少 @SpringBootTest 添加 @SpringBootTest 注解
包路径不正确 调整测试类包位置或显式指定扫描路径
依赖未正确引入 检查 spring-boot-starter-test 依赖
Bean未被Spring管理 添加 @Component 等注解或检查扫描配置
混淆JUnit4/JUnit5 注解 移除 @RunWith，使用JUnit5注解

通过添加MyBatis相关的说明，对提示词进行细化后，回答如下，挨个对照检查，依旧不能解决问题。

现象 解决方案
Mapper接口未被扫描到 添加 @MapperScan 或检查包路径
数据源配置错误导致MyBatis初始化失败 检查测试环境的 application.properties
XML映射文件未找到 确认 mybatis.mapper-locations 配置正确
MyBatis依赖版本不兼容 升级至与Spring Boot 3.2兼容的版本
测试未使用 @Transactional 导致数据库回滚问题 添加 @Transactional 注解在测试类或方法

无奈之下只能继续搜索，找到了印度三哥写的这篇文章，其中说明maven-surefire-plugin的版本太旧，需要进行升级。

去对应报错信息处查看，确实如此

maven-surefire-plugin插件版本

在模块pom文件中添加如下高亮部分的配置

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.22.0</version>
        </plugin>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <version>${spring.boot.version}</version>
            <executions>
                <execution>
                    <goals>
                        <goal>repackage</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

重新执行mvn clean compile test，可看出能正常执行成功。

命令行中通过maven运行成功