如何指定服务器来获取EJB？ [英] How do I specify a server to get an EJB from?

问题描述

在Java EE中，从远程服务器获取EJB的方式是在JNDI中查找。该规范为给定的bean类型定义了JNDI名称。

In java EE, the way you get an EJB from a remote server is by looking it up in JNDI. The specification defines the JNDI name for a given bean type.

但是，这似乎只是想要从本地计算机上获取一个bean。我想把bean从一个远程服务器上删除，就像大多数用户一样。如何指定服务器URL？我将地图传递给 InitialContext 构造函数？

However, this seems to be only if you want to get a bean off your local computer. I want to get the bean off a remote server, like most users would. How do I specify the server URL? Do I pass a map to the InitialContext constructor?

注意：另外一个问题几乎是一样的，但是从规范中定义了便携式JNDI名称后，已经过时了。

Note: There is another question that is pretty much the same, but that has become out of date since the definition of portable JNDI names by the specification.

推荐答案

您可以使用与运行服务器端时使用的代码完全相同的代码执行远程EJB的JNDI查找：

You do JNDI lookups of remote EJBs using exactly the same code as you would use when running server-side:

Context context = new InitialContext();  // No properties needed
MyEJB myEjbInstance = (MyEJB) context.lookup("ejb/MyEJB");

或者，您当然可以注意：

Or, of course, you can inject it:

@EJB
private MyEJB myEjbInstance;

为了使命名上下文有效，您必须以Java EE应用程序客户机的形式运行应用程序。应用程序客户端就像一个常规的独立Java程序，标准的 main 方法;唯一的区别是它需要以不同的方式运行。在Java EE规范中没有指定这种方式，所以每个应用程序服务器都有自己的方法。

To make the naming context work, you must run your application as a Java EE application client. An application client is exactly like a regular standalone Java program, with a standard main method; the only difference is that it needs to be run in a different manner. That manner is not specified in the Java EE Spec, so each application server has its own way of doing it.

GlassFish需要一个应用程序客户端设置几个系统属性。具体来说，您必须在您的类路径中包含 lib / gf-installer.jar 及其清单引用的所有jar，并且必须设置 org。 omg.CORBA.ORBInitialHost 和 org.omg.CORBA.ORBInitialPort 系统属性。

GlassFish, for example, requires an application client to include some special jars in the classpath, and set a couple system properties. Specifically, you must include lib/gf-installer.jar and all the jars referenced by its manifest in your classpath, and you must set the org.omg.CORBA.ORBInitialHost and org.omg.CORBA.ORBInitialPort system properties.

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