Create example with Spring stereotype annotations

- Use component scanning for loading bean definitions
- Use Spring stereotypes to define poincuts

spring-mvc-java/src/main/java/org/baeldung/aop/PerformanceAspect.java

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+package org.baeldung.aop;
+
+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;
+
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Logger;
+
+@Aspect
+@Component
+public class PerformanceAspect {
+
+    private static Logger logger = Logger.getLogger(PerformanceAspect.class.getName());
+
+    @Pointcut("within(@org.springframework.stereotype.Repository *)")
+    public void repositoryClassMethods() {};
+
+    @Around("repositoryClassMethods()")
+    public Object measureMethodExecutionTime(ProceedingJoinPoint pjp) throws Throwable {
+        long start = System.nanoTime();
+        Object retval = pjp.proceed();
+        long end = System.nanoTime();
+        String methodName = pjp.getSignature().getName();
+        logger.info("Execution of " + methodName + " took " + TimeUnit.NANOSECONDS.toMillis(end - start) + " ms");
+        return retval;
+    }
+
+}

spring-mvc-java/src/main/java/org/baeldung/dao/FooDao.java

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+package org.baeldung.dao;
+
+import org.springframework.stereotype.Repository;
+
+@Repository
+public class FooDao {
+    public String findById(Long id) {
+        return "Bazz";
+    }
+}