Question

我正在为一个简单的EJB项目编写一个客户端，我已经在Eclipse中运行的Wildfly 8上本地部署了它。

我的界面：

package com.jwt.ejb.business;

import javax.ejb.Remote;

@Remote
public interface Hello {

    public String sayHello();
}

我的实施：

package com.jwt.ejb.businesslogic;

import javax.ejb.Stateless;

import com.jwt.ejb.business.Hello;

@Stateless
public class HelloBean implements Hello {

    public HelloBean() { 
    }

    public String sayHello() { 
        return "Hello Boss Welcome to EJB";
    } 
}

我的客户：

package com.jwt.ejb.test;

import java.util.Hashtable;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import com.jwt.ejb.business.Hello;
import com.jwt.ejb.businesslogic.HelloBean;

public class Client {
    public static void main(String[] args) {
        Hello bean = doLookup();
        if (bean != null)
            System.out.println(bean.sayHello());
    }

    private static Hello doLookup() {
        Context context = null;
        Hello bean = null;
        try {
            final Hashtable jndiProperties = new Hashtable();
            jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
            context = new InitialContext(jndiProperties);
            bean = (Hello) context.lookup(getLookupString());

        } catch (NamingException e) {
            e.printStackTrace();
        }
        return bean;
    }

    private static String getLookupString() throws NamingException {
        final String appName = "";
        final String moduleName = "EJBTest";
        final String distinctName = "";
        final String beanName = HelloBean.class.getSimpleName();
        final String viewClassName = Hello.class.getName();
        return "ejb:" + appName + "/" + moduleName + "/" + distinctName + "/" + beanName + "!" + viewClassName;
    }
}

当我运行它时，我得到了这个例外：

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
    at javax.naming.spi.NamingManager.getInitialContext(Unknown Source)
    at javax.naming.InitialContext.getDefaultInitCtx(Unknown Source)
    at javax.naming.InitialContext.getURLOrDefaultInitCtx(Unknown Source)
    at javax.naming.InitialContext.lookup(Unknown Source)
    at com.jwt.ejb.test.Client.doLookup(Client.java:26)
    at com.jwt.ejb.test.Client.main(Client.java:15)
Exception in thread "main" java.lang.NullPointerException
    at com.jwt.ejb.test.Client.main(Client.java:16)

官方文档也是这样的： https://docs.jboss.org/author/display/AS71/EJB+invocations+from+a+remote+client+using+JNDI

问题出在哪里？

我在谈论boss-ejb-client.properties的帖子时，但我不知道该放什么。据我所知，我可以拥有这个属性文件，或者像我一样以编程方式声明这些属性。

Answer 1

除了您使用Wildfly 8并引用JBoss AS 7.1的文档之外，您还缺少JNDI属性上的InitialContextFactory。

Wildfly关于通过JNDI进行EJB调用的文档是here。因此，您应该执行以下操作：

void doBeanLookup() {
    Properties jndiProperties = new Properties();
    jndiProperties.put(Context.INITIAL_CONTEXT_FACTORY, "org.jboss.naming.remote.client.InitialContextFactory");
    jndiProperties.put(Context.PROVIDER_URL, "http-remoting://localhost:8080");

    // This is an important property to set if you want to do EJB invocations via the remote-naming project
    jndiProps.put("jboss.naming.client.ejb.context", true);
    // create a context passing these properties
    Context ctx = new InitialContext(jndiProps);

    // lookup the bean Hello
    Hello bean = (Hello) ctx.lookup(getLookupString());
}

在您的pom.xml中，您应该拥有以下内容：

<dependency>
    <groupId>org.wildfly</groupId>
    <artifactId>wildfly-ejb-client-bom</artifactId>
    <version>8.0.0.Final</version>
    <type>pom</type>
</dependency>

如果您想使用 http-remoting 协议，则应在getLookupString方法中移除ejb:并显示

http-remoting 客户端假定远程查找中的JNDI名称与java：jboss / exported命名空间相关，绝对JNDI名称的查找将失败。

可在Wildfly 8 Remote JNDI Reference Update Draft上找到更多信息。

Wildfly 8上的简单EJB项目中的NoInitialContextException

1 个答案: