我想用指定的注解(比如@Monitor)监视所有类的所有公共方法(注意:注解在类级别)。这可能是什么切入点?注意:我使用的是@AspectJ 风格的 Spring AOP。
10 回答
您应该将类型切入点与方法切入点结合起来。
这些切入点将用于查找标有 @Monitor 注释的类中的所有公共方法:
@Pointcut("within(@org.rejeev.Monitor *)")
public void beanAnnotatedWithMonitor() {}
@Pointcut("execution(public * *(..))")
public void publicMethod() {}
@Pointcut("publicMethod() && beanAnnotatedWithMonitor()")
public void publicMethodInsideAClassMarkedWithAtMonitor() {}
建议结合前两个切入点的最后一个切入点,您就完成了!
使用注释,如问题中所述。
注解:@Monitor
类注释,app/PagesController.java
:
package app;
@Controller
@Monitor
public class PagesController {
@RequestMapping(value = "/", method = RequestMethod.GET)
public @ResponseBody String home() {
return "w00t!";
}
}
方法注释,app/PagesController.java
:
package app;
@Controller
public class PagesController {
@Monitor
@RequestMapping(value = "/", method = RequestMethod.GET)
public @ResponseBody String home() {
return "w00t!";
}
}
自定义注释,app/Monitor.java
:
package app;
@Component
@Target(value = {ElementType.METHOD, ElementType.TYPE})
@Retention(value = RetentionPolicy.RUNTIME)
public @interface Monitor {
}
注释方面,app/MonitorAspect.java
:
package app;
@Component
@Aspect
public class MonitorAspect {
@Before(value = "@within(app.Monitor) || @annotation(app.Monitor)")
public void before(JoinPoint joinPoint) throws Throwable {
LogFactory.getLog(MonitorAspect.class).info("monitor.before, class: " + joinPoint.getSignature().getDeclaringType().getSimpleName() + ", method: " + joinPoint.getSignature().getName());
}
@After(value = "@within(app.Monitor) || @annotation(app.Monitor)")
public void after(JoinPoint joinPoint) throws Throwable {
LogFactory.getLog(MonitorAspect.class).info("monitor.after, class: " + joinPoint.getSignature().getDeclaringType().getSimpleName() + ", method: " + joinPoint.getSignature().getName());
}
}
启用 AspectJ servlet-context.xml
,:
<aop:aspectj-autoproxy />
包括 AspectJ 库,pom.xml
:
<artifactId>spring-aop</artifactId>
<artifactId>aspectjrt</artifactId>
<artifactId>aspectjweaver</artifactId>
<artifactId>cglib</artifactId>
像这样的东西:
@Before("execution(* com.yourpackage..*.*(..))")
public void monitor(JoinPoint jp) {
if (jp.getTarget().getClass().isAnnotationPresent(Monitor.class)) {
// perform the monitoring actions
}
}
请注意,在此之前,您不能对同一类有任何其他建议,因为代理后注释将丢失。
利用
@Before("execution(* (@YourAnnotationAtClassLevel *).*(..))")
public void beforeYourAnnotation(JoinPoint proceedingJoinPoint) throws Throwable {
}
像这样标记您的方面方法就足够了:
@After("@annotation(com.marcot.CommitTransaction)")
public void after() {
看看这个关于这个的分步指南。
最简单的方法似乎是:
@Around("execution(@MyHandling * com.exemple.YourService.*(..))")
public Object aroundServiceMethodAdvice(final ProceedingJoinPoint pjp)
throws Throwable {
// perform actions before
return pjp.proceed();
// perform actions after
}
它将拦截在“YourService”类中使用“@MyHandling”特别注释的所有方法的执行。要想毫无例外地拦截所有方法,直接在类上打上注解即可。
无论这里的私有/公共范围如何,但请记住,spring-aop 不能在同一实例(通常是私有的)中使用方面进行方法调用,因为在这种情况下它不使用代理类。
我们在这里使用@Around 建议,但它与@Before、@After 或任何建议的语法基本相同。
顺便说一句,@MyHandling 注解必须像这样配置:
@Retention(RetentionPolicy.RUNTIME)
@Target( { ElementType.METHOD, ElementType.TYPE })
public @interface MyHandling {
}
您还可以将切入点定义为
public pointcut publicMethodInsideAClassMarkedWithAtMonitor() : execution(public * (@Monitor *).*(..));
我与您分享一个有用的代码,它是创建一个可以在类或方法中使用的注释。
@Target({TYPE, METHOD})
@Retention(RUNTIME)
@Documented
public @interface AnnotationLogger {
/**
* It is the parameter is to show arguments in the method or the class.
*/
boolean showArguments() default false;
}
@Aspect
@Component
public class AnnotationLoggerAspect {
@Autowired
private Logger logger;
private static final String METHOD_NAME = "METHOD NAME: {} ";
private static final String ARGUMENTS = "ARGS: {} ";
@Before(value = "@within(com.org.example.annotations.AnnotationLogger) || @annotation(com.org.example.annotations.AnnotationLogger)")
public void logAdviceExecutionBefore(JoinPoint joinPoint){
CodeSignature codeSignature = (CodeSignature) joinPoint.getSignature();
AnnotationLogger annotationLogger = getAnnotationLogger(joinPoint);
if(annotationLogger!= null) {
StringBuilder annotationLoggerFormat = new StringBuilder();
List<Object> annotationLoggerArguments = new ArrayList<>();
annotationLoggerFormat.append(METHOD_NAME);
annotationLoggerArguments.add(codeSignature.getName());
if (annotationLogger.showArguments()) {
annotationLoggerFormat.append(ARGUMENTS);
List<?> argumentList = Arrays.asList(joinPoint.getArgs());
annotationLoggerArguments.add(argumentList.toString());
}
logger.error(annotationLoggerFormat.toString(), annotationLoggerArguments.toArray());
}
}
private AnnotationLogger getAnnotationLogger(JoinPoint joinPoint) {
AnnotationLogger annotationLogger = null;
try {
MethodSignature signature = (MethodSignature) joinPoint.getSignature();
Method method = joinPoint.getTarget().getClass().
getMethod(signature.getMethod().getName(), signature.getMethod().getParameterTypes());
if (method.isAnnotationPresent(AnnotationLogger.class)){
annotationLogger = method.getAnnotation(AnnotationLoggerAspect.class);
}else if (joinPoint.getTarget().getClass().isAnnotationPresent(AnnotationLoggerAspect.class)){
annotationLogger = joinPoint.getTarget().getClass().getAnnotation(AnnotationLoggerAspect.class);
}
return annotationLogger;
}catch(Exception e) {
return annotationLogger;
}
}
}
来自春天的AnnotationTransactionAspect
:
/**
* Matches the execution of any public method in a type with the Transactional
* annotation, or any subtype of a type with the Transactional annotation.
*/
private pointcut executionOfAnyPublicMethodInAtTransactionalType() :
execution(public * ((@Transactional *)+).*(..)) && within(@Transactional *);
您可以使用 Spring 的 PerformanceMonitoringInterceptor 并使用 beanpostprocessor 以编程方式注册建议。
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Inherited
@Documented
public @interface Monitorable
{
}
public class PerformanceMonitorBeanPostProcessor extends ProxyConfig implements BeanPostProcessor, BeanClassLoaderAware, Ordered,
InitializingBean
{
private Class<? extends Annotation> annotationType = Monitorable.class;
private ClassLoader beanClassLoader = ClassUtils.getDefaultClassLoader();
private Advisor advisor;
public void setBeanClassLoader(ClassLoader classLoader)
{
this.beanClassLoader = classLoader;
}
public int getOrder()
{
return LOWEST_PRECEDENCE;
}
public void afterPropertiesSet()
{
Pointcut pointcut = new AnnotationMatchingPointcut(this.annotationType, true);
Advice advice = getInterceptor();
this.advisor = new DefaultPointcutAdvisor(pointcut, advice);
}
private Advice getInterceptor()
{
return new PerformanceMonitoringInterceptor();
}
public Object postProcessBeforeInitialization(Object bean, String beanName)
{
return bean;
}
public Object postProcessAfterInitialization(Object bean, String beanName)
{
if(bean instanceof AopInfrastructureBean)
{
return bean;
}
Class<?> targetClass = AopUtils.getTargetClass(bean);
if(AopUtils.canApply(this.advisor, targetClass))
{
if(bean instanceof Advised)
{
((Advised)bean).addAdvisor(this.advisor);
return bean;
}
else
{
ProxyFactory proxyFactory = new ProxyFactory(bean);
proxyFactory.copyFrom(this);
proxyFactory.addAdvisor(this.advisor);
return proxyFactory.getProxy(this.beanClassLoader);
}
}
else
{
return bean;
}
}
}