Tomcat的JDBC，JNDI问题6.0.26

一尘不染

Tomcat的JDBC，JNDI问题6.0.26

tomcat

问候，我正在开发一个Web应用程序，需要使用Enterprise JDBC类使用JNDI设置数据源。我正在将Netbeans
6.9捆绑的tomcat（6.0.26 app）服务器与mysql
5.xx一起使用。来自关系的数据库值显示在我的jsp页面中，而在tomcat初始化过程中，它表示如下：

。。

SEVERE: Servlet.service() for servlet jsp threw exception
java.lang.ClassCastException: org.apache.tomcat.dbcp.dbcp.BasicDataSource cannot be cast to javax.naming.Context
        at org.apache.jsp.Hello_jsp._jspService(Hello_jsp.java:141)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
        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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        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:298)
        at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:859)
        at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
        at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
        at java.lang.Thread.run(Thread.java:619)
Jul 25, 2010 1:28:25 AM org.apache.catalina.core.ApplicationContext log
INFO: SessionListener: contextDestroyed()
Jul 25, 2010 1:28:25 AM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: contextDestroyed()
Jul 25, 2010 1:28:32 AM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: contextInitialized()
Jul 25, 2010 1:28:32 AM org.apache.catalina.core.ApplicationContext log
INFO: SessionListener: contextInitialized()
Jul 25, 2010 1:28:40 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet jsp threw exception
javax.naming.NameNotFoundException: Name nexusirm is not bound in this Context
        at org.apache.naming.NamingContext.lookup(NamingContext.java:770)
        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:140)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:781)
        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 org.apache.naming.SelectorContext.lookup(SelectorContext.java:152)
        at javax.naming.InitialContext.lookup(InitialContext.java:392)
        at org.apache.jsp.Hello_jsp._jspService(Hello_jsp.java:141)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
        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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        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:298)
        at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:859)
        at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
        at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
        at java.lang.Thread.run(Thread.java:619)
Jul 25, 2010 1:29:50 AM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet jsp threw exception
javax.naming.NameNotFoundException: Name jdbc is not bound in this Context
        at org.apache.naming.NamingContext.lookup(NamingContext.java:770)
        at org.apache.naming.NamingContext.lookup(NamingContext.java:153)
        at org.apache.naming.SelectorContext.lookup(SelectorContext.java:152)
        at javax.naming.InitialContext.lookup(InitialContext.java:392)
        at org.apache.jsp.Hello_jsp._jspService(Hello_jsp.java:143)
        at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
        at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374)
        at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
        at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
        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.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        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:298)
        at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:859)
        at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:579)
        at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1555)
        at java.lang.Thread.run(Thread.java:619)
Jul 25, 2010 1:30:10 AM org.apache.catalina.core.ApplicationContext log

。。

我的/WEB-INF/web.xml中包含以下内容

<resource-ref>
         <res-ref-name>jdbc/NexusIRM</res-ref-name>
         <res-type>javax.sql.DataSource</res-type>
         <res-auth>Container</res-auth>
         <res-sharing-scope>Shareable</res-sharing-scope> 
</resource-ref>

以及以下内容在我的/META-INF/context.xml中

 <Resource name="jdbc/NexusIRM"
           auth="Container"
           type="javax.sql.DataSource"
           driverClassName="com.mysql.jdbc.Driver"
           url="jdbc:mysql://localhost:3306/nexusirm"
           username="root"
           password=""
           maxActive="20"
           maxIdle="30"
           maxWait="-1"

 />

我的应用程序代码如下：

                <%
 try{

Context initCtx = new InitialContext();

DataSource ds = (DataSource)
  initCtx.lookup("java:comp/env/jdbc/NexusIRM");

Connection conn=ds.getConnection();

Statement stmt=conn.createStatement();
ResultSet rs=stmt.executeQuery("SELECT * FROM irm_gtresult");

if(rs.next())
    {
    for(int i=1;i<9;i++){
out.write(rs.getString(i));
}
}
conn.close();
}catch(SQLException e)
{out.write(e.getMessage());
e.printStackTrace();}

%>

我很好奇为什么在完美执行应用程序时会抛出这些异常！

阅读 151

2020-06-16

共1个答案

一尘不染

尝试这个 …

Connection conn;
try
{   
    // Obtain our environment naming context
    Context initCtx = new InitialContext();
    Context envCtx = (Context) initCtx.lookup("java:comp/env");

    // Look up our data source
    DataSource ds = (DataSource)
      envCtx.lookup("jdbc/NexusIRM");

    // Allocate and use a connection from the pool
    Connection conn = ds.getConnection();
    ... use this connection to access the database ...
}
finally
{
   if(conn != null)
       conn.close();
}

注意：确保最后关门！！！

2020-06-16