自动实例化会话bean?

问题描述

我有一个会话bean

I have a session bean

<managed-bean>
  <managed-bean-name>vdcAddBean</managed-bean-name>
  <managed-bean-class>com.cloud.appsportfolio.jsf.vdc.beans.VDCAddBean</managed-bean-class>
  <managed-bean-scope>session</managed-bean-scope>
</managed-bean>

现在，我将这个bean注入到一个请求中:

Now, I am injecting this bean into a request one:

<managed-bean>
      <managed-bean-name>providerSelectionBean</managed-bean-name>
      <managed-bean-class>com.cloud.appsportfolio.jsf.sourcing.ProviderSelectionBean</managed-bean-class>
      <managed-bean-scope>request</managed-bean-scope>
      <managed-property>
        <property-name>vdcAddBean</property-name>
        <property-class>com.cloud.appsportfolio.jsf.vdc.beans.VDCAddBean</property-class>
        <value>#{sessionScope.vdcAddBean}</value>
      </managed-property>
</managed-bean>

好吧，当我用providerSelectionBean java代码访问vdcAddBean时，我收到了NPE，因为vdcAddBean尚未初始化.如果我要先进入菜单，那么在后端具有vdcAddBean并返回到providerSelectionBean的页面中，所有工作都很好，因为似乎vdcAddBean已经初始化.

Well, when I'm accessing vdcAddBean in providerSelectionBean java code, I receive a NPE because vdcAddBean is not yet initialized. If I'm going first in my menu, in a page which has vdcAddBean in the back-end and comes back to providerSelectionBean all works great because it seems that vdcAddBean was already initialized.

问题是:在访问providerSelectionBean bean时如何强制vdcAddBean初始化(如果为null)?

The question is: how I can force vdcAddBean to be initialized (if it's null) when accessing providerSelectionBean bean?

谢谢.

推荐答案

替换

<value>#{sessionScope.vdcAddBean}</value>

作者

<value>#{vdcAddBean}</value>

让JSF自动创建bean.

to get JSF to autocreate the bean.

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