Spring AOP 不适用于具有泛型类型返回值的方法

Question

编辑：已解决，因为开头有双星号，我从《Spring Microservices in Action》一书中复制了它

我正在尝试建议一些控制器的方法。

这是方面类：

@Aspect
public class PBLogger {
@Pointcut("execution(** com.sunwell.product..*.*(..))")
public void standardMethod() {
}
@Around("standardMethod()")
public Object log(ProceedingJoinPoint jp) {
...
}
...
}

这是目标方法，我已经确保包名称是正确的。

这个不起作用(没有调用建议方法(：

@RequestMapping(value = "resources/items", method = RequestMethod.GET,
produces = "application/json"
)
public ResponseEntity<Map<String,Object>> getItems(
@RequestHeader(value="Authorization", required = false) String _auth, @RequestParam(value="systemId", required = false) Integer _i ) throws Exception 
{ ... }

如果没有通用返回类型，它可以工作：

@RequestMapping(value = "resources/items", method = RequestMethod.GET,
produces = "application/json"
)
public void getItems(@RequestHeader(value="Authorization", required = false) String _auth, @RequestParam(value="systemId", required = false) Integer _i ) throws Exception 
{ ... }

它也使用带注释的切入点而不是执行

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface Example
{
public String msg();
}
@Aspect
public class PBLogger {

@Pointcut("@annotation(Example)")
public void standardMethod() {
}
@Around("standardMethod()")
public Object log(ProceedingJoinPoint jp) {
...
}
...
}
//target method:
@RequestMapping(value = "resources/items", method = RequestMethod.GET,
produces = "application/json"
)
@Example
public ResponseEntity<Map<String,Object>> getItems(
@RequestHeader(value="Authorization", required = false) String _auth, @RequestParam(value="systemId", required = false) Integer _ ) throws Exception 
{ ... }

Answer 1

目标方法签名不是问题，无论是否是泛型。看看我的MCVE:

目标类别：

请注意，不能将两个方法放在同一个类中，因为它们具有相同的类型擦除。编译器会对此抱怨。

package de.scrum_master.spring.q60474362;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import java.util.Map;
@Component
public class MyTargetClass {
@RequestMapping(
value = "resources/items", method = RequestMethod.GET,
produces = "application/json"
)
public ResponseEntity<Map<String, Object>> getItems(
@RequestHeader(value = "Authorization", required = false) String _auth,
@RequestParam(value = "systemId", required = false) Integer _i
) throws Exception
{
System.out.println("MyTargetClass.getItems");
return null;
}
}

package de.scrum_master.spring.q60474362;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestHeader;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
@Component
public class MyOtherTargetClass {
@RequestMapping(
value = "resources/items", method = RequestMethod.GET,
produces = "application/json"
)
public void getItems(
@RequestHeader(value = "Authorization", required = false) String _auth,
@RequestParam(value = "systemId", required = false) Integer _i
) throws Exception
{
System.out.println("MyOtherTargetClass.getItems");
}
}

方面：

请注意，您的示例切入点中的**没有意义，我将其更改为使用*。如果**有效，你只是幸运的，语法检查并不严格，但我的IDE实际上会抱怨。此外，您并不真正需要my.package..*.*(..)，如果类和方法名称都无关紧要，那么my.package..*(..)就足够了。

package de.scrum_master.spring.q60474362;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;
@Aspect
@Component
public class PBLogger {
@Pointcut("execution(* de.scrum_master.spring..*(..))")
public void standardMethod() {}
@Around("standardMethod()")
public Object log(ProceedingJoinPoint jp) throws Throwable {
System.out.println(jp);
return jp.proceed();
}
}

弹簧驱动程序应用程序&配置：

package de.scrum_master.spring.q60474362;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
@SpringBootApplication
@Configuration
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class Application {
public static void main(String[] args) throws Exception {
try (ConfigurableApplicationContext appContext = SpringApplication.run(Application.class, args)) {
doStuff(appContext);
}
}
private static void doStuff(ConfigurableApplicationContext appContext) throws Exception {
MyTargetClass myTargetClass = appContext.getBean(MyTargetClass.class);
myTargetClass.getItems("x", 11);
MyOtherTargetClass myOtherTargetClass = appContext.getBean(MyOtherTargetClass.class);
myOtherTargetClass.getItems("y", 22);
}
}

控制台日志：

.   ____          _            __ _ _
/\ / ___'_ __ _ _(_)_ __  __ _    
( ( )___ | '_ | '_| | '_ / _` |    
\/  ___)| |_)| | | | | || (_| |  ) ) ) )
'  |____| .__|_| |_|_| |___, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot ::        (v1.5.2.RELEASE)
(...)
2020-03-02 09:00:49.712  INFO 24028 --- [           main] d.s.spring.q60474362.Application         : Started Application in 3.554 seconds (JVM running for 5.157)
execution(ResponseEntity de.scrum_master.spring.q60474362.MyTargetClass.getItems(String,Integer))
MyTargetClass.getItems
execution(void de.scrum_master.spring.q60474362.MyOtherTargetClass.getItems(String,Integer))
MyOtherTargetClass.getItems
(...)

如果它对您不起作用，那么您会遇到其他问题，例如组件扫描没有拾取有问题的目标类，例如由于忘记了@Component注释或其他原因。