org.springframework.orm.jpa: public class: JpaInterceptor

org.springframework.orm.jpa
public class: JpaInterceptor [javadoc | source]

java.lang.Object
   org.springframework.orm.jpa.EntityManagerFactoryAccessor
      org.springframework.orm.jpa.JpaAccessor
         org.springframework.orm.jpa.JpaInterceptor

All Implemented Interfaces:
org.aopalliance.intercept.MethodInterceptor, InitializingBean

This interceptor binds a new JPA EntityManager to the thread before a method call, closing and removing it afterwards in case of any method outcome. If there already is a pre-bound EntityManager (e.g. from JpaTransactionManager, or from a surrounding JPA-intercepted method), the interceptor simply participates in it.

Application code must retrieve a JPA EntityManager via the EntityManagerFactoryUtils.getEntityManager method or - preferably - via a shared EntityManager reference, to be able to detect a thread-bound EntityManager. Typically, the code will look like as follows:

public void doSomeDataAccessAction() {
this.entityManager...
}

Note that this interceptor automatically translates PersistenceExceptions, via delegating to the EntityManagerFactoryUtils.convertJpaAccessException method that converts them to exceptions that are compatible with the org.springframework.dao exception hierarchy (like JpaTemplate does).

This class can be considered a declarative alternative to JpaTemplate's callback approach. The advantages are:

no anonymous classes necessary for callback implementations;
the possibility to throw any application exceptions from within data access code.

The drawback is the dependency on interceptor configuration. However, note that this interceptor is usually not necessary in scenarios where the data access code always executes within transactions. A transaction will always have a thread-bound EntityManager in the first place, so adding this interceptor to the configuration just adds value when fine-tuning EntityManager settings like the flush mode - or when relying on exception translation.

Also see:

JpaTransactionManager

JpaTemplate

author: Juergen - Hoeller

since: 2.0 -

Fields inherited from org.springframework.orm.jpa.EntityManagerFactoryAccessor:
logger

Method from org.springframework.orm.jpa.JpaInterceptor Summary:
invoke, setExceptionConversionEnabled

Methods from org.springframework.orm.jpa.JpaAccessor:
afterPropertiesSet, flushIfNecessary, getEntityManager, getJpaDialect, isFlushEager, setEntityManager, setFlushEager, setJpaDialect, translateIfNecessary

Methods from org.springframework.orm.jpa.EntityManagerFactoryAccessor:
createEntityManager, getEntityManagerFactory, getJpaPropertyMap, getTransactionalEntityManager, setEntityManagerFactory, setJpaProperties, setJpaPropertyMap

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.springframework.orm.jpa.JpaInterceptor Detail:
public Object invoke(MethodInvocation methodInvocation) throws Throwable { // Determine current EntityManager: either the transactional one // managed by the factory or a temporary one for the given invocation. EntityManager em = getTransactionalEntityManager(); boolean isNewEm = false; if (em == null) { logger.debug("Creating new EntityManager for JpaInterceptor invocation"); em = createEntityManager(); isNewEm = true; TransactionSynchronizationManager.bindResource(getEntityManagerFactory(), new EntityManagerHolder(em)); } try { Object retVal = methodInvocation.proceed(); flushIfNecessary(em, !isNewEm); return retVal; } catch (RuntimeException rawException) { if (this.exceptionConversionEnabled) { // Translation enabled. Translate if we understand the exception. throw translateIfNecessary(rawException); } else { // Translation not enabled. Don't try to translate. throw rawException; } } finally { if (isNewEm) { TransactionSynchronizationManager.unbindResource(getEntityManagerFactory()); EntityManagerFactoryUtils.closeEntityManager(em); } } }
public void setExceptionConversionEnabled(boolean exceptionConversionEnabled) { this.exceptionConversionEnabled = exceptionConversionEnabled; } Set whether to convert any PersistenceException raised to a Spring DataAccessException, compatible with the `org.springframework.dao` exception hierarchy. Default is "true". Turn this flag off to let the caller receive raw exceptions as-is, without any wrapping.

Method from org.springframework.orm.jpa.JpaInterceptor Detail:

 public Object invoke(MethodInvocation methodInvocation) throws Throwable {
		// Determine current EntityManager: either the transactional one
		// managed by the factory or a temporary one for the given invocation.
		EntityManager em = getTransactionalEntityManager();
		boolean isNewEm = false;
		if (em == null) {
			logger.debug("Creating new EntityManager for JpaInterceptor invocation");
			em = createEntityManager();
			isNewEm = true;
			TransactionSynchronizationManager.bindResource(getEntityManagerFactory(), new EntityManagerHolder(em));
		}
		try {
			Object retVal = methodInvocation.proceed();
			flushIfNecessary(em, !isNewEm);
			return retVal;
		}
		catch (RuntimeException rawException) {
			if (this.exceptionConversionEnabled) {
				// Translation enabled. Translate if we understand the exception.
				throw translateIfNecessary(rawException);
			}
			else {
				// Translation not enabled. Don't try to translate.
				throw rawException;
			}
		}
		finally {
			if (isNewEm) {
				TransactionSynchronizationManager.unbindResource(getEntityManagerFactory());
				EntityManagerFactoryUtils.closeEntityManager(em);
			}
		}
}

 public  void setExceptionConversionEnabled(boolean exceptionConversionEnabled) {
	                                     	 
		this.exceptionConversionEnabled = exceptionConversionEnabled;
}

org.springframework.dao

Default is "true". Turn this flag off to let the caller receive raw exceptions as-is, without any wrapping.