DelegatingDataSource Spring boot

问题

I am trying to implement Spring Boot AOP for data-source pointcut - where before running any query I need to set client context in DB connection.

I was trying this approach of using DelegatingDataSource. But I am getting below error during server startup

 org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'dataSource': Requested bean is currently in creation: Is there an unresolvable circular reference?

Please let me know DeletegatingDatasource for JNDI based DB lookup.

Edit 1: AOP - I tried to add pointcut execution(public * javax.sql.DataSource+.getConnection(..)). This works only when Spring datasource is used with username/password. Once i deploy in Jboss with JNDI I am getting WildFlyDataSource Proxy error. So, instead of AOP approach I thought of using DelegatingDatasource

   // AOP Example

    @Pointcut("execution(public * javax.sql.DataSource+.getConnection(..))")
    void prepareConnectionPointcut() {
        logger.debug("prepareConnectionPointcut");
    }
    
    @AfterReturning(pointcut = "prepareConnectionPointcut()", returning = "connection")
    void afterPrepareConnection(Connection connection) {
        // Set context in Connection - return same connection for query execution
    }

But when i deploy this code in JBoss - I am getting WildFlyDataSource datasource bean creation error.

Error creating bean with name 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/JndiDataSourceAutoConfiguration.class]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Could not generate CGLIB subclass of class org.jboss.as.connector.subsystems.datasources.WildFlyDataSource: Common causes of this problem include using a final class or a non-visible class; nested exception is org.springframework.cglib.core.CodeGenerationException: java.lang.NoClassDefFoundError-->org/jboss/as/connector/subsystems/datasources/WildFlyDataSource

I have also added proxyTargetClass flag during initialization

@EnableAspectJAutoProxy(proxyTargetClass = true)

回答1:

Thanks @M.Deinum for recommendation of using BeanPostProcessor & Implement DelegatingDatasource for setting client info. Please find snippet below which i have implemented to accomplish this in Spring Boot which works well with JBoos JNDI based connection or Spring Boot URL Datasource connection.

@Component
public class MyBeanPostProcessor implements BeanPostProcessor {

    private static Logger logger = LoggerFactory.getLogger(MyBeanPostProcessor.class);

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {

        if (bean instanceof DataSource) {
            // Check DataSource bean initialization & enclose it with DelegatingDataSource 
            logger.debug("MyBeanPostProcessor:: postProcessAfterInitialization:: DataSource");

            DataSource beanDs = (DataSource) bean;
            return new MyDelegateDS(beanDs);
        }

        return BeanPostProcessor.super.postProcessAfterInitialization(bean, beanName);
    }

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        if (bean instanceof DataSource) {
            logger.debug("MyBeanPostProcessor:: postProcessBeforeInitialization:: DataSource");
        }

        logger.debug("MyBeanPostProcessor:: postProcessBeforeInitialization:: " + beanName);

        return BeanPostProcessor.super.postProcessBeforeInitialization(bean, beanName);
    }

}

My implementation of DelegatingDataSource to handle each user request to set client context in DB connection session

 public class MyDelegateDS extends DelegatingDataSource {

    private static Logger logger = LoggerFactory.getLogger(MyDelegateDS.class);

    public MyDelegateDS(DataSource delegate) {
        super(delegate);
        logger.debug("MyDelegateDS:: constructor");
    }

    @Override
    public Connection getConnection() throws SQLException {
        logger.debug("MyDelegateDS:: getConnection");

        // To do this context only for user Request - to avoid this during Server initialization
        if (RequestContextHolder.getRequestAttributes() != null
                && ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest() != null) {

            logger.debug("MyDelegateDS:: getConnection: valid user request");

            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes())
                    .getRequest();
                    
            // Checking each user request & calling SP to set client context before invoking actual native query/SP
        }

        logger.debug("MyDelegateDS:: getConnection: Not User Request");

        return super.getConnection();
    }

}

Hope this is helpful for someone facing same problem

来源：https://stackoverflow.com/questions/63170441/delegatingdatasource-spring-boot