我用的J2EE服务器是Sun的免费服务器Application Server PE，在运行一个简单的例子时总是报如下的错误：javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial。我的客户端代码也很简单，如下所示：
Context ctx=new InitialContext();
Object o=ctx.lookup("test");
AdviceHome home=(AdviceHome)PortableRemoteObject.narrow(o, AdviceHome.class);
Advice advisor=home.create();
System.out.println(advisor.getAdvice());
Properties properties = new Properties();
//properties.put(Context.INITIAL_CONTEXT_FACTORY, "javax.naming.spi.InitialContextFactory");
properties.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.cosnaming.CNCtxFactory");
properties.put(Context.PROVIDER_URL, "iiop://127.0.0.1:3700");
Context ctx=new InitialContext(properties );
Object o=ctx.lookup("test");
AdviceHome home=(AdviceHome)PortableRemoteObject.narrow(o, AdviceHome.class);
Advice advisor=home.create();
System.out.println(advisor.getAdvice());
Context ctx=new InitialContext();Object o=ctx.lookup("test"); AdviceHome home=(AdviceHome)PortableRemoteObject.narrow(o, AdviceHome.class);Advice advisor=home.create();System.out.println(advisor.getAdvice());在网上搜索了一下相关的网页，有人说是没有指定jndi环境变量，于是又试着修改了下代码：
Properties properties = new Properties();//properties.put(Context.INITIAL_CONTEXT_FACTORY, "javax.naming.spi.InitialContextFactory");properties.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.cosnaming.CNCtxFactory");properties.put(Context.PROVIDER_URL, "iiop://127.0.0.1:3700");Context ctx=new InitialContext(properties );Object o=ctx.lookup("test"); AdviceHome home=(AdviceHome)PortableRemoteObject.narrow(o, AdviceHome.class);Advice advisor=home.create();System.out.println(advisor.getAdvice());无论我用哪个上下文工厂，都得不到预期的效果，很郁闷。于是看了下我之前看的那本Beginning J2EE1.4 From Novice to Professional，因为那本书上的范例都运行的好好的。按照书上的步骤，我将j2ee安装目录下的lib目录中的appserv-rt.jar文件加到classpath中，并且把代码还原为上面的第一段代码，于是一切都正常了。