創建JNDI Java Bean錯誤

我想在應用程序中創建一個JNDI bean，但是錯誤「無法創建資源實例」在第一個代碼塊的第三行出現。我按照http://tomcat.apache.org/tomcat-5.5-doc/jndi-resources-howto.html中所示的步驟執行。創建JNDI Java Bean錯誤

這裏不用代碼：

豆實例化：

  Context initCtx = new InitialContext(); 
      Context envCtx = (Context) initCtx.lookup("java:comp/env"); 
      MyBean bean = (MyBean) envCtx.lookup("bean/MyBeanFactory"); 

      System.out.println("foo = " + bean.getFoo() + ", bar = " + 
          bean.getBar());

類爲myBean：

package com.company.intrasc.funcionarios; 
public class MyBean { 
    private String foo = "Default Foo"; 

    public String getFoo() { 
    return (this.foo); 
    } 

    public void setFoo(String foo) { 
    this.foo = foo; 
    } 

    private int bar = 0; 

    public int getBar() { 
    return (this.bar); 
    } 

    public void setBar(int bar) { 
    this.bar = bar; 
    } 

}

類MyBeanFactory：

package com.company.intrasc.factory; 

import java.util.Enumeration; 
import java.util.Hashtable; 
import javax.naming.Context; 
import javax.naming.Name; 
import javax.naming.NamingException; 
import javax.naming.RefAddr; 
import javax.naming.Reference; 
import javax.naming.spi.ObjectFactory; 
import com.company.intrasc.funcionarios.MyBean; 

public class MyBeanFactory implements ObjectFactory { 

    public Object getObjectInstance(Object obj, 
     Name name, Context nameCtx, Hashtable environment) 
     throws NamingException { 

     // Acquire an instance of our specified bean class 
     MyBean bean = new MyBean(); 

     // Customize the bean properties from our attributes 
     Reference ref = (Reference) obj; 
     Enumeration addrs = ref.getAll(); 
     while (addrs.hasMoreElements()) { 
      RefAddr addr = (RefAddr) addrs.nextElement(); 
      String name1 = addr.getType(); 
      String value = (String) addr.getContent(); 
      if (name1.equals("foo")) { 
       bean.setFoo(value); 
      } else if (name1.equals("bar")) { 
       try { 
        bean.setBar(Integer.parseInt(value)); 
       } catch (NumberFormatException e) { 
        throw new NamingException("Invalid 'bar' value " + value); 
       } 
      } 
     } 

     // Return the customized instance 
     return (bean); 

    } 

}

的web.xml在應用程序文件夾：

<resource-env-ref> 
    <description>Object factory for MyBean instances.</description> 
    <resource-env-ref-name>bean/MyBeanFactory</resource-env-ref-name> 
    <resource-env-ref-type>com.company.intrasc.funcionarios.MyBean</resource-env-ref-type> 
</resource-env-ref>

server.xml的上下文配置：

<Resource name="bean/MyBeanFactory" auth="Container" type="com.company.intrasc.funcionarios.MyBean" factory="com.company.intrasc.factory.MyBeanFactory" bar="23"/>

堆棧跟蹤：

javax.naming.NamingException: Cannot create resource instance 
    at org.apache.naming.factory.ResourceEnvFactory.getObjectInstance(ResourceEnvFactory.java:114) 
    at javax.naming.spi.NamingManager.getObjectInstance(Unknown Source) 
    at org.apache.naming.NamingContext.lookup(NamingContext.java:793) 
    at org.apache.naming.NamingContext.lookup(NamingContext.java:140) 
    at org.apache.naming.NamingContext.lookup(NamingContext.java:781) 
    at org.apache.naming.NamingContext.lookup(NamingContext.java:153) 
    at com.company.intrasc.servlet.Logon.executa(Logon.java:81) 
    at com.company.intrasc.servlet.Controller.service(Controller.java:80) 
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) 
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) 
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) 
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293) 
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859) 
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602) 
    at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) 
    at java.lang.Thread.run(Unknown Source)

的類爲myBean和MyBeanFactory被輸出到CATALINA_HOME/lib中在壓縮JAR。服務器是Tomcat 6，IDE是Eclipse Indigo，系統（在開發機器中）是Windows Vista。什麼應該出問題？

來源

2012-05-28 Alex

定義「不起作用」。例外？沒有？還有別的嗎？ –

@JimGarrison，對不起，我用錯誤更新了問題，這只是「無法創建資源實例」，這是一個非常普遍的原因。它出現在第一個代碼塊的第三行。 – Alex

請發佈**整個**堆棧跟蹤，包括所有「由...引起」部分。 –

最後我發現了這個問題。我不知道這對任何人是否有用，但問題出在server.xml中的<context>標籤中。該標籤必須理解<Resource>標籤，我忘記了這一標籤。所以，上下文並不是「看到」資源。

來源

2012-05-30 19:16:31 Alex

創建JNDI Java Bean錯誤

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