fix: Use AOP proxy for DataSource telemetry to preserve bean type

Author: dngyukm

instrumentation/spring/spring-boot-autoconfigure/src/main/java/io/opentelemetry/instrumentation/spring/autoconfigure/internal/instrumentation/jdbc/DataSourcePostProcessor.java

@@ -11,7 +11,10 @@
 import io.opentelemetry.instrumentation.spring.autoconfigure.internal.properties.InstrumentationConfigUtil;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import javax.sql.DataSource;
+import org.aopalliance.intercept.MethodInterceptor;
+import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.aop.scope.ScopedProxyUtils;
+import org.springframework.aop.support.AopUtils;
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.core.Ordered;
@@ -50,7 +53,7 @@ public Object postProcessAfterInitialization(Object bean, String beanName) {
         && !isRoutingDatasource(bean)
         && !ScopedProxyUtils.isScopedTarget(beanName)) {
       DataSource dataSource = (DataSource) bean;
-      return JdbcTelemetry.builder(openTelemetryProvider.getObject())
+      DataSource wrapped = JdbcTelemetry.builder(openTelemetryProvider.getObject())
           .setStatementSanitizationEnabled(
               InstrumentationConfigUtil.isStatementSanitizationEnabled(
                   configPropertiesProvider.getObject(),
@@ -66,6 +69,12 @@ public Object postProcessAfterInitialization(Object bean, String beanName) {
                   .getBoolean("otel.instrumentation.jdbc.experimental.transaction.enabled", false))
           .build()
           .wrap(dataSource);
+      ProxyFactory proxyFactory = new ProxyFactory(new Class<?>[] {DataSource.class});
+      proxyFactory.setTarget(bean);
+      proxyFactory.addAdvice(
+          (MethodInterceptor) invocation -> AopUtils.invokeJoinpointUsingReflection(
+              wrapped, invocation.getMethod(), invocation.getArguments()));
+      return proxyFactory.getProxy();
     }
     return bean;
   }