Question

使用环境

Netbeans 8.0 +

glassfish 4 +

jdk 1.8

请注意，如果您不使用接口视图，此示例效果很好。如果我们使用本地或远程接口，则效果不佳

远程界面

package packt;
import javax.ejb.Remote;
@Remote
public interface SphereBeanRemote {
     public double computeVolume(double radius);
}

以上界面的实施

package packt;
import javax.ejb.Stateless;
@Stateless
public class SphereBean implements SphereBeanRemote {
    @Override
    public double computeVolume(double radius) {
         return (4.0/3.0)*Math.PI*(radius*radius*radius);
    }

}

访问它的客户端（servlet）

import java.io.*;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import packt.SphereBean;

@WebServlet(urlPatterns = {"/SphereServlet"})
public class SphereServlet extends HttpServlet {
    @EJB
    SphereBean sphere;
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {

            out.println("<!DOCTYPE html>");
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet SphereServlet</title>");            
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Servlet SphereServlet at " + request.getContextPath() + "</h1>");
            out.println("<h1>" + sphere.computeVolume(18)  + "</h1>");
            out.println("</body>");
            out.println("</html>");
        }
    }

      @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }
      @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    @Override
    public String getServletInfo() {
        return "Short description";
    }

}

错误 HTTP状态500 - 内部服务器错误

输入例外报告

messageInternal Server Error

description服务器遇到内部错误，导致无法完成此请求。

例外

javax.servlet.ServletException：实例化servlet类SphereServlet时出错

根本原因

com.sun.enterprise.container.common.spi.util.InjectionException：为类创建托管对象时出错：class SphereServlet

根本原因

com.sun.enterprise.container.common.spi.util.InjectionException：异常尝试注入Remote ejb-ref name = SphereServlet / sphere，Remote 3.x interface = packt.SphereBean，ejb-link = null，lookup =，mappedName =，jndi-name = packt.SphereBean，refType =类SphereServlet中的Session：查找失败的＆＃39; java：comp / env / SphereServlet / sphere＆＃39;在SerialContext中[myEnv = {java.naming.factory.initial = com.sun.enterprise.naming.impl.SerialInitContextFactory，java.naming.factory.state = com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl， java.naming.factory.url.pkgs = com.sun.enterprise.naming}

根本原因

javax.naming.NamingException：＆＃39; java：comp / env / SphereServlet / sphere＆＃39;查找失败在SerialContext中[myEnv = {java.naming.factory.initial = com.sun.enterprise.naming.impl.SerialInitContextFactory，java.naming.factory.state = com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl， java.naming.factory.url.pkgs = com.sun.enterprise.naming} [根异常是javax.naming.NamingException：异常解析Ejb for＆＃39; Remote ejb-ref name = SphereServlet / sphere，Remote 3.x interface = packt.SphereBean，ejb-link = null，lookup =，mappedName =，jndi-name = packt.SphereBean，refType = Session＆＃39; 。用于查找的实际（可能是内部）远程JNDI名称是＆＃39; packt.SphereBean＃packt.SphereBean＆＃39; [根异常是javax.naming.NamingException：查找失败了＆＃39; packt.SphereBean＃packt.SphereBean＆＃39;在SerialContext中[myEnv = {java.naming.factory.initial = com.sun.enterprise.naming.impl.SerialInitContextFactory，java.naming.factory.state = com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl， java.naming.factory.url.pkgs = com.sun.enterprise.naming} [根异常是javax.naming.NameNotFoundException：packt.SphereBean＃packt.SphereBean not found]]]

根本原因

javax.naming.NamingException：为远程ejb-ref name = SphereServlet / sphere解析Ejb的异常，Remote 3.x interface = packt.SphereBean，ejb-link = null，lookup =，mappedName =，jndi -name = packt.SphereBean，RefType的=会话＆＃39; 。用于查找的实际（可能是内部）远程JNDI名称是＆＃39; packt.SphereBean＃packt.SphereBean＆＃39; [根异常是javax.naming.NamingException：查找失败了＆＃39; packt.SphereBean＃packt.SphereBean＆＃39;在SerialContext中[myEnv = {java.naming.factory.initial = com.sun.enterprise.naming.impl.SerialInitContextFactory，java.naming.factory.state = com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl， java.naming.factory.url.pkgs = com.sun.enterprise.naming} [根异常是javax.naming.NameNotFoundException：packt.SphereBean＃packt.SphereBean not found]]

根本原因

javax.naming.NamingException：＆＃39; packt.SphereBean＃packt.SphereBean＆＃39;在SerialContext中[myEnv = {java.naming.factory.initial = com.sun.enterprise.naming.impl.SerialInitContextFactory，java.naming.factory.state = com.sun.corba.ee.impl.presentation.rmi.JNDIStateFactoryImpl， java.naming.factory.url.pkgs = com.sun.enterprise.naming} [根异常是javax.naming.NameNotFoundException：packt.SphereBean＃packt.SphereBean not found]

根本原因

javax.naming.NameNotFoundException：找不到packt.SphereBean＃packt.SphereBean

注意GlassFish Server Open Source Edition 4。1日志中提供了异常的完整堆栈跟踪及其根本原因。 GlassFish Server开源4.1版

Answer 1

该规范的§4.9.8规定：

以下是公开无界面视图的会话bean的要求：



bean类必须指定它通过bean类定义或部署描述符公开无接口视图。以下规则适用：



如果bean没有公开任何其他客户端视图（本地，远程，无接口，2.x远程主页，2.x本地主页，Web服务）并且其implements子句为空，则bean定义无界面视图。



如果bean公开了至少一个其他客户端视图，那么bean指定它通过bean类或部署描述符中的LocalBean注释公开无接口视图。

因此，改变您的实施：

package packt;
import javax.ejb.Stateless;
import javax.ejb.LocalBean;

@LocalBean
@Stateless
public class SphereBean implements SphereBeanRemote {
    @Override
    public double computeVolume(double radius) {
         return (4.0/3.0)*Math.PI*(radius*radius*radius);
    }
}

应该为你做的伎俩。

但是，如果您想要实际使用本地/远程接口，那么这是您在注入时应该使用的类型：

@WebServlet(urlPatterns = {"/SphereServlet"})
public class SphereServlet extends HttpServlet {

    @EJB
    SphereBeanRemote sphere;

    ...

添加接口（本地和远程）时无法运行ejb应用程序

1 个答案: