AspectJ编译时织入启动异常：ajc$perSingletonInstance为空及构造方法缺失

问题根源 #

你的切面类EnsureFromMonolith使用@RequiredArgsConstructor生成带参构造，没有无参构造。在AspectJ编译时织入（CTW）模式下，AspectJ默认会尝试用无参构造实例化切面；同时你用@Component希望Spring管理切面，两种实例化机制冲突，导致启动时抛出异常。

解决方案 #

方案1：给切面添加无参构造方法（最简方案） #

通过Lombok同时生成带参和无参构造，让AspectJ能实例化切面，Spring再通过带参构造注入真实依赖：

@Aspect
@Component
@RequiredArgsConstructor
@NoArgsConstructor(force = true) // force=true为final字段赋默认值，避免编译报错
public class EnsureFromMonolith {
    private final Dependency1 dep1;
    private final Dependency2 dep2;

    @Around("execution(* com.xyz..*(..))")
    public Object aroundAdvice(ProceedingJoinPoint joinPoint) throws Throwable {
        // 你的环绕通知逻辑
        return joinPoint.proceed();
    }
}

方案2：配置AspectJ插件让Spring管理切面实例 #

修改pom.xml中的AspectJ插件配置，引入Spring的AspectJ支持，让Spring负责切面的实例化和依赖注入：

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>aspectj-maven-plugin</artifactId>
    <version>1.14.0</version> <!-- 适配Java21的版本 -->
    <dependencies>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjtools</artifactId>
            <version>${aspectj.version}</version>
        </dependency>
    </dependencies>
    <executions>
        <execution>
            <id>compile</id>
            <goals>
                <goal>compile</goal>
            </goals>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
                <complianceLevel>${java.version}</complianceLevel>
                <aspectLibraries>
                    <aspectLibrary>
                        <groupId>org.springframework</groupId>
                        <artifactId>spring-aspects</artifactId>
                    </aspectLibrary>
                </aspectLibraries>
                <weaveDirectories>
                    <weaveDirectory>${project.build.directory}/unwoven-classes</weaveDirectory>
                </weaveDirectories>
                <Xlint>ignore</Xlint>
            </configuration>
        </execution>
    </executions>
</plugin>

同时确保项目引入spring-aspects依赖：

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-aspects</artifactId>
</dependency>

方案3：调整编译流程，兼容Lombok与AspectJ #

让AspectJ插件直接处理Lombok生成的构造方法，调整插件配置顺序：

<!-- Maven编译插件：编译到unwoven-classes并处理Lombok -->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>${maven-compiler.version}</version>
    <configuration>
        <source>${java.version}</source>
        <target>${java.version}</target>
        <outputDirectory>${project.build.directory}/unwoven-classes</outputDirectory>
        <annotationProcessorPaths>
            <path>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </path>
        </annotationProcessorPaths>
    </configuration>
</plugin>

<!-- AspectJ插件：处理Lombok并织入切面 -->
<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>aspectj-maven-plugin</artifactId>
    <version>1.14.0</version>
    <dependencies>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjtools</artifactId>
            <version>${aspectj.version}</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>${lombok.version}</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok-aspectj</artifactId>
            <version>${lombok.version}</version>
        </dependency>
    </dependencies>
    <executions>
        <execution>
            <id>compile</id>
            <goals>
                <goal>compile</goal>
            </goals>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
                <complianceLevel>${java.version}</complianceLevel>
                <weaveDirectories>
                    <weaveDirectory>${project.build.directory}/unwoven-classes</weaveDirectory>
                </weaveDirectories>
                <proc>none</proc> <!-- 禁用javac注解处理，由AspectJ处理Lombok -->
                <Xlint>ignore</Xlint>
            </configuration>
        </execution>
    </executions>
</plugin>

验证步骤 #

1. 执行mvn clean compile确认编译无报错
2. 检查target/classes下的切面类字节码，确认构造方法符合预期
3. 启动应用，验证异常是否消失
4. 测试目标方法，确认切面环绕通知逻辑生效

内容的提问来源于stack exchange，提问作者Surabhya Aryal