执行 Head First EJB 第一个示例时出错

Question

我正在关注 Head First EJB。 我知道它有 EJB 2.0，它和现在 EJB 3.1 一样旧。但我认为 Head first book 是一本适合像我们这样的业余爱好者学习的好书。

我正在使用 J2ee 1.3.1 RI 和 jdk 1.4。 我运行了“部署”工具以通过 EJB 进行部署，现在我有一个 ejb 客户端 JAVA 程序，如下所示：

import javax.naming.*;
import java.rmi.*;
import javax.rmi.*;
import headfirst.*;
import javax.ejb.*;

import java.util.*;

public class AdviceClient {
    public static void main(String[] args){
        new AdviceClient().go();
    }

    public void go(){
        try{

            Properties props=new Properties();
            props.setProperty(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.rmi.registry.RegistryContextFactory");
            //props.setProperty(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.fscontext.RefFSContextFactory");
            //env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.rmi.registry.RegistryContextFactory");
            //props.setProperty(Context.INITIAL_CONTEXT_FACTORY,"com.sun.enterprise.naming.SerialInitContextFactory");
            props.setProperty(Context.PROVIDER_URL,"rmi://localhost:1050"); 
            //props.setProperty("java.naming.provider.url","rmi://localhost:1099");

            Context ic = new InitialContext(props);
            Object o = ic.lookup("Advisor");

            AdviceHome home = (AdviceHome)PortableRemoteObject.narrow(o,AdviceHome.class);

            Advice advisor = home.create();
            System.out.println(advisor.getAdvice());
        }
        catch(Exception ex){
            ex.printStackTrace();
        }
    }
}






Following the book, I compiled the program. The "Properties" part is something not mentioned in the example. I got it from some other examples on the web. Now, that when I am executing the client, am getting the following error:


F:\EJBProject\advice>java -classpath AdviceAppClient.jar;. AdviceClient
javax.naming.CommunicationException [Root exception is java.rmi.ConnectIOException: error during JRMP connection establishment; nested exception is:

        java.net.SocketTimeoutException: Read timed out]
        at com.sun.jndi.rmi.registry.RegistryContext.lookup(Unknown Source)
        at com.sun.jndi.rmi.registry.RegistryContext.lookup(Unknown Source)
        at javax.naming.InitialContext.lookup(Unknown Source)
        at AdviceClient.go(AdviceClient.java:26)
        at AdviceClient.main(AdviceClient.java:11)
Caused by: java.rmi.ConnectIOException: error during JRMP connection establishment; nested exception is:
        java.net.SocketTimeoutException: Read timed out
        at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
        at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
        at sun.rmi.server.UnicastRef.newCall(Unknown Source)
        at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
        ... 5 more
Caused by: java.net.SocketTimeoutException: Read timed out
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(Unknown Source)
        at java.net.SocketInputStream.read(Unknown Source)
        at java.io.BufferedInputStream.fill(Unknown Source)
        at java.io.BufferedInputStream.read(Unknown Source)
        at java.io.DataInputStream.readByte(Unknown Source)

请帮忙。 我被困在这里了。 我想参加 OCBDD 考试！

问候， 舒瓦尼克

Answer 1

终于解决了。

如果您在运行第一个 EJB 示例时遇到障碍，只需按照以下步骤运行 HeadFirst EJB 的第一个示例即可。

软件 1. j2sdk1.4.1 - jdk 2. j2sdkee1.3.1 - j2ee RI 3. CMD（命令提示符）

使用 c:\\j2sdkee1.3.1\\lib\\j2ee.jar 库编译所有类。 现在，创建一个应用程序并在 RI 中部署 EJB。 下载本书中所示的应用程序客户端。

现在，棘手的部分来了。

使用以下 jars 编译客户端类

javac -classpath AdviceAppClient.jar;c:\\j2sdkee1.3.1\\lib\\j2ee.jar AdviceClient.java

接下来，运行客户端如下

java -cp AdviceAppClient.jar;c:\\j2sdkee1.3.1\\lib\\j2ee.jar;c:\\j2sdk1.4.1\\jre\\lib\\rt.jar;。 咨询客户