以编程方式从JSF托管的bean中注入EJB bean [英] Inject EJB bean from JSF managed bean programmatically

问题描述

解决方案方案

您无法以编程方式注入。但是您可以以编程方式获取它。 也可以通过JNDI使用EJB 。通常，您会发现服务器启动日志中打印的这些JNDI名称/别名。至少JBoss / WildFly这样做。

有不同的JNDI名称别名：

 java：全球/ APP_NAME [/ MODULE_NAME] / EJB_NAME 

 java：app / MODULE_NAME / EJB_NAME 

 java：module / EJB_NAME 

其中 / APP_NAME 是名称的WAR或EAR应用程序，而 / MODULE_NAME 是EAR应用程序的EJB模块的名称，或者在单个WAR应用程序的情况下为WAR模块（并且在 java：global 中将不存在，否则重复 / APP_NAME ）和 / EJB_NAME 默认为EJB类的类名。

java：global 可以通过整个服务器访问。 java：app 只能从同一应用程序（WAR或EAR）内部访问。 java：module 只能从同一个模块内部进行访问（在单次WAR的情况下，EJB为EAR或WAR本身）。

JSF管理的bean显然在WAR内。如果您有一个单一的WAR应用程序，那么 java：module / EJB_NAME 必须工作。如果您有一个EAR项目，那么EJB显然在EJB模块中，在这种情况下， java：module 将无法正常工作，您需要 java：app 或 java：global 。

所以，给出如下的EJB，

  @Stateless 
 public class FooService {} 
  

它是通过JNDI命名为foo_war的单一WAR项目在JSF托管的bean中可用如下（通常您在 @PostConstruct 方法中执行此操作）：

  InitialContext jndi = new InitialContext（）; 
 
 FooService fooService =（FooService）jndi.lookup（java：module / FooService）; 
 //或
 FooService fooService =（FooService）jndi.lookup（java：app / foo_war / FooService）; 
 //或
 FooService fooService =（FooService）jndi.lookup（java：global / foo_war / FooService）;或者在名为foo_ear的名为foo_ejb的EJB模块的EAR项目中，其中包含EJB类（而JSF托管的bean在EAR项目的WAR模块中）：
  InitialContext jndi = new InitialContext（）; 
 
 FooService fooService =（FooService）jndi.lookup（java：app / foo_ejb / FooService）; 
 //或
 FooService fooService =（FooService）jndi.lookup（java：global / foo_ear / foo_ejb / FooService）; 
  
 
I have EJB stateless bean.

How can I inject it to JSF managed bean by programmatic instead of @EJB annotation?
解决方案
You can't inject it programmatically. You can however obtain it programmatically. EJBs are also available via JNDI. Usually, you find those JNDI names/aliases printed in server startup log. At least JBoss / WildFly does that.

There are different JNDI name aliases:
java:global/APP_NAME[/MODULE_NAME]/EJB_NAME


java:app/MODULE_NAME/EJB_NAME


java:module/EJB_NAME
Where /APP_NAME is the name of the WAR or EAR application, and /MODULE_NAME is the name of the EJB module in case of an EAR application, or the WAR module in case of a single-WAR application (and this will be absent in java:global as it otherwise repeats /APP_NAME), and /EJB_NAME defaults to the class name of the EJB class.

The java:global is accessible through the entire server. The java:app is only accessible from inside the same application (WAR or EAR). The java:module is only accessible from inside the same module (EJB in case of EAR or WAR itself in case of single-WAR). 

A JSF managed bean is obviously inside a WAR. If you've a single-WAR application, then java:module/EJB_NAME must work. If you've however an EAR project, then the EJB is obviously inside the EJB module, in that case the java:module won't work and you'd need java:app or java:global. 

So, given an EJB like below,
@Stateless
public class FooService {}
it's in a single-WAR project named "foo_war" via JNDI available in a JSF managed bean as follows (usually you do that in @PostConstruct method):
InitialContext jndi = new InitialContext();

FooService fooService = (FooService) jndi.lookup("java:module/FooService");
// Or
FooService fooService = (FooService) jndi.lookup("java:app/foo_war/FooService");
// Or
FooService fooService = (FooService) jndi.lookup("java:global/foo_war/FooService");
or in an EAR project named "foo_ear" with an EJB module named "foo_ejb" with therein the EJB class (while the JSF managed bean is in the WAR module of the EAR project):
InitialContext jndi = new InitialContext();

FooService fooService = (FooService) jndi.lookup("java:app/foo_ejb/FooService");
// Or
FooService fooService = (FooService) jndi.lookup("java:global/foo_ear/foo_ejb/FooService");


                        
这篇关于以编程方式从JSF托管的bean中注入EJB bean的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！