javax.naming.NameNotFoundException：Name [servlet.TestEJB / meuEJB]在此上下文中未绑定。无法找到[servlet.TestEJB] [英] javax.naming.NameNotFoundException: Name [servlet.TestEJB/meuEJB] is not bound in this Context. Unable to find [servlet.TestEJB]

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问题描述

我在此应用程序中收到一个错误，该错误通过点击POST来调用servlet的index.html页面上的按钮将用户保留在BD上。
我会非常感谢一个解决方案很长时间我试图找到错误的原因。
我认为错误应该是放一些笔记或没有找到servlet的时间。



错误：

  javax.servlet.ServletException：实例化servlet类的错误servlet.TestEJB 
 org.apache.catalina.authenticator.AuthenticatorBase.invoke（AuthenticatorBase.java:502）
 org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:79）
 org.apache.catalina.valves.AbstractAccessLogValve.invoke（AbstractAccessLogValve.java:610）
 org.apache .catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:518）
 org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1091）
 org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler .process（AbstractProtocol.java:668）
 org.apache.coyote.http11.Http11NioProtocol $ Http11ConnectionHandler.process（Http11NioProtocol.java:223）
 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor .doRun（NioEndpoint.java:1517） 
 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.run（NioEndpoint.java:1474）
 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）
根本原因
 
 javax.naming.NameNotFoundException：名称[servlet.TestEJB / meuEJB]在此上下文中未绑定。无法找到[servlet.TestEJB]。 
 org.apache.naming.NamingContext.lookup（NamingContext.java:818）
 org.apache.naming.NamingContext.lookup（NamingContext.java:166）
 org.apache.catalina。 authentator.AuthenticatorBase.invoke（AuthenticatorBase.java:502）
 org.apache.catalina.valves.ErrorReportValve.invoke（ErrorReportValve.java:79）
 org.apache.catalina.valves.AbstractAccessLogValve.invoke（ AbstractAccessLogValve.java:610）
 org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:518）
 org.apache.coyote.http11.AbstractHttp11Processor.process（AbstractHttp11Processor.java:1091） 
 org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process（AbstractProtocol.java:668）
 org.apache.coyote.http11.Http11NioProtocol $ Http11ConnectionHandler.process（Http11NioProtocol.java:223）
 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.doRun（NioEndpoint.java:1517）
 org.apache.tomcat.util.net.NioEndpoint $ SocketProcessor.run（NioEndpoint .java：1474）
 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）

SERVLET：

  @WebServlet（ / TestEJB）
 public class TestEJB extends HttpServlet {
 
 private static final long serialVersionUID = 1L; 
 
 @EJB 
 MissatgesEJB meuEJB; 
 
 / *（非Javadoc）
 * @see javax.servlet.http.HttpServlet＃doPost（javax.servlet.http.HttpServletRequest，javax.servlet.http.HttpServletResponse）
 * / 
 @Override 
 protected void doPost（HttpServletRequest req，HttpServletResponse resp）throws ServletException，IOException {
 resp.setContentType（text / html; charset = UTF-8）; 
 
 try（PrintWriter out = resp.getWriter（））{
 
 out.println（<！DOCTYPE html>）; 
 out.println（< html>）; 
 out.println（< head>）; 
 out.println（< title> Servlet TestEJB< / title>）; 
 out.println（< / head>）; 
 out.println（< body>）; 
 out.println（< h1> Proves Whatsapp< / h1>）; 
 
 Usuaris usuari = new Usuaris（robert_1994，Paucasals33，Bruch）; 
 
 out.println（Insertant Usuari ...+ meuEJB.insertarUsuari（usuari）+< br />）; 
 
 out.println（< / body>）; 
 out.println（< / html>）; 
} 
 
} 
 
}

方法：

  @Stateless 
 public class MissatgesEJB {
 
 @PersistenceUnit 
 EntityManagerFactory emf 
 
 public String insertarUsuari（Usuaris u）{
 
 EntityManager em = emf.createEntityManager（）; 
 
 try {
 // Excriu a la BD。 
 em.persist（u）; 
 
 //Forçema que escrigui ara ala BD。 
 em.flush（）; 
 
 returnok; 
 
} catch（Exception ex）{
 
 return ex.getMessage（）; 
 
} finally {
 
 em.close（）; 
} 
 
 
} 
 
}

persistence.xml：

 <？xml version =1.0encoding =UTF-8 ？> 
< persistence version =2.1
 xmlns =http://xmlns.jcp.org/xml/ns/persistencexmlns：xsi =http://www.w3.org/ 2001 / XMLSchema-instance
 xsi：schemaLocation =http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd > 
< persistence-unit name =JPA-1transaction-type =RESOURCE_LOCAL> 
< provider> org.eclipse.persistence.jpa.PersistenceProvider< / provider> 
< class> beans.Historial< / class> 
< class> beans.Missatges< / class> 
< class> beans.Usuaris< / class> 
<属性> 
< property name =javax.persistence.jdbc.drivervalue =com.mysql.jdbc.Driver/> 
< property name =javax.persistence.jdbc.urlvalue =jdbc：mysql：// localhost / bdwhatsapp/> 
< property name =javax.persistence.jdbc.uservalue =marti/> 
< property name =javax.persistence.jdbc.passwordvalue =Paucasals33/> 
< property name =javax.persistence.schema-generation.database.action
 value =none/> 
< / properties> 
< / persistence-unit> 
< / persistence>


解决方案

您的堆栈跟踪告诉您正在使用Tomcat。 / p> 

 在org.apache.tomcat.util.threads.TaskThread $ WrappingRunnable.run（TaskThread.java:61）

Tomcat不是EJB容器。它是一个准系统的JSP / Servlet容器。为了获取编译代码，在webapp的 / WEB-INF / lib 中投入一堆JAR并不能让Tomcat变成一个真正的Java EE容器。 p>

对于EJB，您需要一个真正的Java EE容器。通过 TomEE 替换Tomcat， WildFly 或 Payara 。那些是支持EJB，JPA，JSF，JAX-RS和所有其他真正的东西的真正的Java EE容器。



另请参见：




I get an error on this application that keeps users on a BD via a button on the index.html page that calls the servlet by clicking on POST. I would greatly appreciate a solution for a long time I'm trying to find the error causes. I think the error should be the time to put some notes or did not find the servlet.

ERROR:

javax.servlet.ServletException: Error instantiating servlet class servlet.TestEJB
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
    org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474)
    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 [servlet.TestEJB/meuEJB] is not bound in this Context. Unable to find [servlet.TestEJB].
    org.apache.naming.NamingContext.lookup(NamingContext.java:818)
    org.apache.naming.NamingContext.lookup(NamingContext.java:166)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518)
    org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091)
    org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:668)
    org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:223)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1517)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1474)
    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)

SERVLET:

@WebServlet("/TestEJB")
public class TestEJB extends HttpServlet{

    private static final long serialVersionUID = 1L;

    @EJB
    MissatgesEJB meuEJB;

    /* (non-Javadoc)
     * @see javax.servlet.http.HttpServlet#doPost(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        resp.setContentType("text/html;charset=UTF-8");

        try (PrintWriter out = resp.getWriter()) {

            out.println("<!DOCTYPE html>");
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet TestEJB</title>");
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Proves Whatsapp</h1>");

            Usuaris usuari = new Usuaris("robert_1994", "Paucasals33", "Bruch");

            out.println("Insertant Usuari... " + meuEJB.insertarUsuari(usuari) + "<br/>");

            out.println("</body>");
            out.println("</html>");
        }

    }

}

Method:

@Stateless
public class MissatgesEJB {

    @PersistenceUnit
    EntityManagerFactory emf;

    public String insertarUsuari(Usuaris u) {

        EntityManager em = emf.createEntityManager();

        try {
            // Excriu a la BD.
            em.persist(u);

            // Forçem a que escrigui ara ala BD.
            em.flush();

            return "ok";

        } catch (Exception ex) {

            return ex.getMessage();

        } finally {

            em.close();
        }


    }

}

persistence.xml:

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1"
    xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
    <persistence-unit name="JPA-1" transaction-type="RESOURCE_LOCAL">
        <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
        <class>beans.Historial</class>
        <class>beans.Missatges</class>
        <class>beans.Usuaris</class>
        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/bdwhatsapp" />
            <property name="javax.persistence.jdbc.user" value="marti" />
            <property name="javax.persistence.jdbc.password" value="Paucasals33" />
            <property name="javax.persistence.schema-generation.database.action"
                value="none" />
        </properties>
    </persistence-unit>
</persistence>

解决方案

Your stack trace tells you're using Tomcat.

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

Tomcat is not an EJB container. It's a barebones JSP/Servlet container. Throwing in a bunch of JARs in webapp's /WEB-INF/lib just in order to get code to compile doesn't magically turn Tomcat into a true Java EE container.

For EJB, you need a real Java EE container. Replace Tomcat by TomEE, WildFly or Payara. Those are real Java EE containers supporting EJB, JPA, JSF, JAX-RS and all other real stuff out the box.

See also:

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