Question

我有以下EJB实现一个简单的ActiveMQ消息入队。 ActiveMQ代码本身工作得很好。这部署在TomEE服务器上。

SenderBean类：

package Beans;

import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;

@LocalBean
@Stateless
public class SenderBean {

    private ConnectionFactory factory = null;
    private Connection connection = null;
    private Session session = null;
    private Destination destination = null;
    private MessageProducer producer = null;

    public SenderBean() {

    }

    public void sendMessage() {

        try {
            factory = new ActiveMQConnectionFactory(
                    ActiveMQConnection.DEFAULT_BROKER_URL);
            connection = factory.createConnection();
            connection.start();
            session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
            destination = session.createQueue("SAMPLEQUEUE");
            producer = session.createProducer(destination);
            TextMessage message = session.createTextMessage();
            message.setText("Hello ...This is a sample message..sending from FirstClient");
            producer.send(message);
            System.out.println("Sent: " + message.getText());

            connection.close(); 

        } catch (JMSException e) {
            e.printStackTrace();
        }
    }
}

我还有以下类尝试在servlet中使用bean。如果我包含@EJB注释，如下例所示，servlet会在收到post时抛出异常。但是，如果我删除注释并使用new SenderBean()实例化bean类，则一切正常。可能是什么原因造成的？

SenderServlet类：

package Servlets;

import Beans.ReceiverBean;
import Beans.SenderBean;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(name = "SenderServlet")
public class SenderServlet extends HttpServlet {

    @EJB
    SenderBean senderBean;

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    senderBean.sendMessage();
    }
}

500错误后HttpServletResponse收到异常：

HTTP Status 500 - Error instantiating servlet class Servlets.SenderServlet</h1><div class="line"></div><p><b>type</b> Exception report</p><p><b>message</b> <u>Error instantiating servlet class Servlets.SenderServlet</u></p><p><b>description</b> <u>The server encountered an internal error that prevented it from fulfilling this request.</u></p><p><b>exception</b></p><pre>javax.servlet.ServletException: Error instantiating servlet class Servlets.SenderServlet
    org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.tomee.catalina.OpenEJBSecurityListener$RequestCapturer.invoke(OpenEJBSecurityListener.java:97)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:745)

root cause javax.naming.NameNotFoundException: Name [Servlets.SenderServlet/senderBean] is not bound in this Context. Unable to find [Servlets.SenderServlet].
    org.apache.naming.NamingContext.lookup(NamingContext.java:816)
    org.apache.naming.NamingContext.lookup(NamingContext.java:173)
    org.apache.tomee.catalina.OpenEJBValve.invoke(OpenEJBValve.java:44)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.tomee.catalina.OpenEJBSecurityListener$RequestCapturer.invoke(OpenEJBSecurityListener.java:97)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:784)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:802)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1410)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:745)

爆炸的神器：

Answer 1

你没有与activemq或hibernate发生类路径冲突吗？提供的库不在WEB-INF / lib中吗？

@EJB注释导致servlet停止工作

1 个答案: