将方面建议与通配符一起使用会导致多个触发器和异常
Using Aspect advice with wildcard leading to multiple triggers and exceptions
我是 AOP 新手，创建了一个简单的 SpringBoot 项目来学习它。我创建了一个日志记录方面，它在触发 returns String 的 get 方法之前简单地记录一条消息。添加通配符后（因此它会触发所有 get 方法，无论 return 类型如何），我看到了一个奇怪的行为 - 它似乎触发了内部方法调用 spring 用于加载上下文然后遇到 NPE。不知道如何解决这个问题，代码如下：
@SpringBootApplication
@ComponentScan
@EnableAutoConfiguration
public class AspectOrientedProgrammingApplication implements ApplicationContextAware {
private static ApplicationContext applicationContext;
public static void main(String[] args) {
SpringApplication.run(AspectOrientedProgrammingApplication.class, args);
ShapeService shapeService = applicationContext.getBean(ShapeService.class);
System.out.println(shapeService.getCircle().getName());
}
@Override
public void setApplicationContext(ApplicationContext context) throws BeansException {
applicationContext = context;
}
}
我的圈子class:
@Component
public class Circle {
@Value("${spring.app.circleName}")
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
形状服务class:
@Component
public class ShapeService {
@Autowired
private Triangle triangle;
@Autowired
private Circle circle;
public Triangle getTriangle() {
return triangle;
}
public void setTriangle(Triangle triangle) {
this.triangle = triangle;
}
public Circle getCircle() {
return circle;
}
public void setCircle(Circle circle) {
this.circle = circle;
}
}
看点class：
@Aspect
@Component
public class LoggingAspect {
@Before("execution(public * get*())") // works fine with "execution(public String getName())"
public void loggingAdvice(){
System.out.println("Advice run: Get method called");
}
}
运行 结果如下：
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils (file:/C:/Users/Arslan/.m2/repository/org/springframework/spring-core/5.3.15/spring-core-5.3.15.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2022-02-06 08:14:28.566 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.boot.web.servlet.RegistrationBean.onStartup(javax.servlet.ServletContext) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
Advice run: Get method called
2022-02-06 08:14:29.163 INFO 8004 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2022-02-06 08:14:29.179 INFO 8004 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-02-06 08:14:29.179 INFO 8004 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-02-06 08:14:29.327 INFO 8004 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-02-06 08:14:29.327 INFO 8004 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2959 ms
Advice run: Get method called
2022-02-06 08:14:29.339 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.OncePerRequestFilter.doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) throws javax.servlet.ServletException,java.io.IOException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.339 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.GenericFilterBean.init(javax.servlet.FilterConfig) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.363 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.OncePerRequestFilter.doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) throws javax.servlet.ServletException,java.io.IOException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.363 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.GenericFilterBean.init(javax.servlet.FilterConfig) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.391 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.OncePerRequestFilter.doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) throws javax.servlet.ServletException,java.io.IOException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.391 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.GenericFilterBean.init(javax.servlet.FilterConfig) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
2022-02-06 08:14:29.548 ERROR 8004 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Exception starting filter [requestContextFilter]
java.lang.NullPointerException: null
at org.springframework.web.filter.GenericFilterBean.init(GenericFilterBean.java:241) ~[spring-web-5.3.15.jar:5.3.15]
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:272) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:106) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4613) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5256) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:478) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory$$FastClassBySpringCGLIB$c83fa9f.invoke(<generated>) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:783) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:698) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory$$EnhancerBySpringCGLIB$$e5201eaa.getWebServer(<generated>) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.15.jar:5.3.15]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.6.3.jar:2.6.3]
at com.arslan.javabrains.AspectOrientedProgrammingApplication.main(AspectOrientedProgrammingApplication.java:20) ~[classes/:na]
2022-02-06 08:14:29.548 ERROR 8004 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Exception starting filter [characterEncodingFilter]
这是一个功能，而不是 AOP 的错误，您可以实现 cross-cutting 范围广泛的关注点。 wide scope是默认的，如果不限制的话。这适用于本机 AspectJ 和 Spring AOP。我们这里说的是后者。
“编织世界”是一个典型的 AOP 初学者错误，即写太多 widely-scoped 切入点。在 Spring AOP 中，这可能导致拦截内部 Spring 组件或 third-party 组件，有时这可能正是您想要的，具体取决于您的方面的目的。然而，在许多情况下，您只是想将方面应用于您自己的应用程序，希望它位于自己的基础包中，例如 org.acme.myapp。然后，您只需将 && within(org.acme.myapp..*) 添加到您的切入点，以便将这些包（以及它们的子包 ..* ）中的所有内容作为潜在的 AOP 目标。
因此，对于您的简单日志记录建议，它看起来像这样：
@Before("execution(public * get*()) && within(org.acme.myapp..*)")
public void loggingAdvice(JoinPoint joinPoint) {
// Instead of a static message, log what we are actually intercepting
System.out.println(joinPoint);
}
当然，就像您注意到的那样，您也可以扩展 execution 切入点以添加一些范围，但首先这会使切入点更难阅读，其次它对切入点没有帮助除了 execution.
我是 AOP 新手，创建了一个简单的 SpringBoot 项目来学习它。我创建了一个日志记录方面，它在触发 returns String 的 get 方法之前简单地记录一条消息。添加通配符后（因此它会触发所有 get 方法，无论 return 类型如何），我看到了一个奇怪的行为 - 它似乎触发了内部方法调用 spring 用于加载上下文然后遇到 NPE。不知道如何解决这个问题，代码如下：
@SpringBootApplication
@ComponentScan
@EnableAutoConfiguration
public class AspectOrientedProgrammingApplication implements ApplicationContextAware {
private static ApplicationContext applicationContext;
public static void main(String[] args) {
SpringApplication.run(AspectOrientedProgrammingApplication.class, args);
ShapeService shapeService = applicationContext.getBean(ShapeService.class);
System.out.println(shapeService.getCircle().getName());
}
@Override
public void setApplicationContext(ApplicationContext context) throws BeansException {
applicationContext = context;
}
}
我的圈子class:
@Component
public class Circle {
@Value("${spring.app.circleName}")
private String name;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
形状服务class:
@Component
public class ShapeService {
@Autowired
private Triangle triangle;
@Autowired
private Circle circle;
public Triangle getTriangle() {
return triangle;
}
public void setTriangle(Triangle triangle) {
this.triangle = triangle;
}
public Circle getCircle() {
return circle;
}
public void setCircle(Circle circle) {
this.circle = circle;
}
}
看点class：
@Aspect
@Component
public class LoggingAspect {
@Before("execution(public * get*())") // works fine with "execution(public String getName())"
public void loggingAdvice(){
System.out.println("Advice run: Get method called");
}
}
运行 结果如下：
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils (file:/C:/Users/Arslan/.m2/repository/org/springframework/spring-core/5.3.15/spring-core-5.3.15.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of org.springframework.cglib.core.ReflectUtils
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
2022-02-06 08:14:28.566 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.boot.web.servlet.RegistrationBean.onStartup(javax.servlet.ServletContext) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
Advice run: Get method called
2022-02-06 08:14:29.163 INFO 8004 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8080 (http)
2022-02-06 08:14:29.179 INFO 8004 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2022-02-06 08:14:29.179 INFO 8004 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.56]
2022-02-06 08:14:29.327 INFO 8004 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2022-02-06 08:14:29.327 INFO 8004 --- [ main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 2959 ms
Advice run: Get method called
2022-02-06 08:14:29.339 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.OncePerRequestFilter.doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) throws javax.servlet.ServletException,java.io.IOException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.339 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.GenericFilterBean.init(javax.servlet.FilterConfig) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.363 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.OncePerRequestFilter.doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) throws javax.servlet.ServletException,java.io.IOException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.363 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.GenericFilterBean.init(javax.servlet.FilterConfig) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.391 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.OncePerRequestFilter.doFilter(javax.servlet.ServletRequest,javax.servlet.ServletResponse,javax.servlet.FilterChain) throws javax.servlet.ServletException,java.io.IOException] because it is marked as final: Consider using interface-based JDK proxies instead!
2022-02-06 08:14:29.391 INFO 8004 --- [ main] o.s.aop.framework.CglibAopProxy : Unable to proxy interface-implementing method [public final void org.springframework.web.filter.GenericFilterBean.init(javax.servlet.FilterConfig) throws javax.servlet.ServletException] because it is marked as final: Consider using interface-based JDK proxies instead!
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
Advice run: Get method called
2022-02-06 08:14:29.548 ERROR 8004 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Exception starting filter [requestContextFilter]
java.lang.NullPointerException: null
at org.springframework.web.filter.GenericFilterBean.init(GenericFilterBean.java:241) ~[spring-web-5.3.15.jar:5.3.15]
at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:272) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:106) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4613) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5256) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:140) ~[na:na]
at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.apache.catalina.startup.Tomcat.start(Tomcat.java:486) ~[tomcat-embed-core-9.0.56.jar:9.0.56]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:123) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:478) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:211) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory$$FastClassBySpringCGLIB$c83fa9f.invoke(<generated>) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:783) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:753) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:698) ~[spring-aop-5.3.15.jar:5.3.15]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory$$EnhancerBySpringCGLIB$$e5201eaa.getWebServer(<generated>) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:577) ~[spring-context-5.3.15.jar:5.3.15]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:145) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:414) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:302) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1303) ~[spring-boot-2.6.3.jar:2.6.3]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1292) ~[spring-boot-2.6.3.jar:2.6.3]
at com.arslan.javabrains.AspectOrientedProgrammingApplication.main(AspectOrientedProgrammingApplication.java:20) ~[classes/:na]
2022-02-06 08:14:29.548 ERROR 8004 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Exception starting filter [characterEncodingFilter]
这是一个功能，而不是 AOP 的错误，您可以实现 cross-cutting 范围广泛的关注点。 wide scope是默认的，如果不限制的话。这适用于本机 AspectJ 和 Spring AOP。我们这里说的是后者。
“编织世界”是一个典型的 AOP 初学者错误，即写太多 widely-scoped 切入点。在 Spring AOP 中，这可能导致拦截内部 Spring 组件或 third-party 组件，有时这可能正是您想要的，具体取决于您的方面的目的。然而，在许多情况下，您只是想将方面应用于您自己的应用程序，希望它位于自己的基础包中，例如 org.acme.myapp。然后，您只需将 && within(org.acme.myapp..*) 添加到您的切入点，以便将这些包（以及它们的子包 ..* ）中的所有内容作为潜在的 AOP 目标。
因此，对于您的简单日志记录建议，它看起来像这样：
@Before("execution(public * get*()) && within(org.acme.myapp..*)")
public void loggingAdvice(JoinPoint joinPoint) {
// Instead of a static message, log what we are actually intercepting
System.out.println(joinPoint);
}
当然，就像您注意到的那样，您也可以扩展 execution 切入点以添加一些范围，但首先这会使切入点更难阅读，其次它对切入点没有帮助除了 execution.