是否可以将 @RequestScoped bean @Inject 到 @Stateless EJB 中？
是否可以将请求范围的 CDI bean 注入无状态会话 bean 中？
我问了一个相关的问题，并认为特定的 CDI @RequestScoped into @Stateless 问题值得单独发表。
在 EJB 方法/@RequestScoped 和 @Stateless 之间传递状态
还问了有关 JMS @MessageDriven beans 的类似问题 - 基本上想了解有关 @Stateless 的相同问题。
Is it possible to inject a request-scoped CDI bean into a Stateless session bean?
I had asked a related question and thought the specific CDI @RequestScoped into @Stateless question merited its own post.
Passing state between EJB methods / @RequestScoped and @Stateless
I also asked a similar question about JMS @MessageDriven beans - basically want to know the same about @Stateless.
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您绝对可以执行您提到的操作，并在
@Stateless会话 bean 和@MessageDrivenbean 中使用@RequestScopedbean。这是 CDI 规范和 TCK 的核心部分，并保证可移植。关于 MDB 的注意事项
请注意，有一个针对使用
@RequestScopedbean 的@Statelessbean 的测试，但没有测试保证@MessageDrivenbean 可以引用@RequestScopedbean。这只是一个疏忽，已针对 Java EE 7 TCK 修复。因此，请注意，如果它不适用于 MDB 情况，则可能不是您的错:)解决方法是简单地将您的 MDB 委托给任何类型的 SessionBean 作为
@Stateless、@Stateful和@Singleton都有@RequestScoped测试。使 EJB 本身具有作用域
而
@Stateless、@Singleton和@MessageDriven可以通过@Inject注入作用域引用code>，它们不能是@RequestScoped或任何其他范围。只有@Stateful模型足够灵活以支持范围。换句话说，您可以将@Statefulbean 类本身注释为@RequestScoped、@SessionScoped等。简单来说
@Stateless、@Singleton已经固定了“范围”。@Singleton本质上是@ApplicationScoped，而@Stateless可能是一些虚构的作用域，例如@InitationScoped，如果那是存在的。@MessageDrivenbean 的生命周期完全取决于驱动它的连接器，因此也不允许具有用户定义的范围。You can absolutely do what you mention and use
@RequestScopedbeans in an@Statelesssession bean and an@MessageDrivenbean. This is a core part of the CDI spec and TCK and guaranteed portable.Note on MDBs
Do be aware that there is a test for a
@Statelessbean that uses a@RequestScopedbean, but there is no test that guarantees a@MessageDrivenbean can reference@RequestScopedbeans. This was just an oversight and is already fixed for the Java EE 7 TCK. So just be aware that if it doesn't work for the MDB case, it may not be your fault :)The workaround would be to simply have your MDB delegate to a SessionBean of any kind as
@Stateless,@Stateful, and@Singletonall have@RequestScopedtests.Making the EJB, itself, scoped
While
@Stateless,@Singletonand@MessageDrivencan have scoped references injected via@Inject, they cannot be@RequestScopedor any other scope. Only the@Statefulmodel is flexible enough to support scopes. In other words, you can annotate the@Statefulbean class itself as@RequestScoped,@SessionScoped, etc..In simple terms
@Stateless,@Singletonhave fixed "scopes" already.@Singletonis essentially@ApplicationScopedand@Statelesswould perhaps be some made-up scope like@InvocationScoped, if that existed. The lifecycle of an@MessageDrivenbean is entirely up to the Connector that drives it and is therefore also not allowed to have user-defined scope.