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Spring Framework 2.0.5 API 文档英文版
JpaInterceptor (Spring Framework API 2.0) - Spring Framework 2.0.5 API 文档英文版
org.springframework.orm.jpa
Class JpaInterceptor
java.lang.Object
org.springframework.orm.jpa.EntityManagerFactoryAccessor
org.springframework.orm.jpa.JpaAccessor
org.springframework.orm.jpa.JpaInterceptor
- All Implemented Interfaces:
- Advice, Interceptor, MethodInterceptor, InitializingBean
public class JpaInterceptor
- extends JpaAccessor
- implements MethodInterceptor
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.
- Since:
- 2.0
- Author:
- Juergen Hoeller
- See Also:
JpaTransactionManager,
JpaTemplate
|
Method Summary |
Object |
invoke(MethodInvocation methodInvocation)
|
void |
setExceptionConversionEnabled(boolean exceptionConversionEnabled)
Set whether to convert any PersistenceException raised to a Spring DataAccessException,
compatible with the org.springframework.dao exception hierarchy. |
| Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
JpaInterceptor
public JpaInterceptor()
setExceptionConversionEnabled
public void setExceptionConversionEnabled(boolean 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.
- See Also:
DataAccessException
invoke
public Object invoke(MethodInvocation methodInvocation)
throws Throwable
- Specified by:
invoke in interface MethodInterceptor
- Throws:
Throwable
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