JDBC 连接池错误

Posted 2023-03-25

【中文标题】JDBC 连接池错误

【英文标题】：JDBC Connection Pooling error

【发布时间】：2014-10-30 07:20:57

【问题描述】：

我正在尝试使用Tomcat 汇集jdbc mysql 连接，为此我是following this blog post

我已将以下代码添加到 Tomcat 中的server.xml（remoteURL 和 remoteDatabase 代表我传递给它的实际 URL 和数据库名称）：

<!-- Modified as suggested by the article on jdbc connection pooling -->
<Connector 
   connectionTimeout="20000" 
   port="8180" 
   protocol="HTTP/1.1" 
   redirectPort="8443"
   maxHttpHeaderSize="8192" 
   maxProcessors="150" 
   maxThreads="150" 
   minSpareThreads="25" 
   maxSpareThreads="75" 
   enableLookups="false"  
   acceptCount="150" 
   disableUploadTimeout="true"
/>   

 <Context 
        path="/dbcp" 
        docBase="dbcp" 
        debug="5" 
        reloadable="true" 
        crossContext="true"
    >
        <Resource 
            name="jdbc/remoteDB" 
            auth="Container" 
            type="javax.sql.DataSource" 
            removeAbandoned="true"
            removeAbandonedTimeout="30" 
            maxActive="100"
            maxIdle="30" 
            maxWait="10000" 
            username="root"
            password="root"
            driverClassName="com.mysql.jdbc.Driver"
            url="jdbc:mysql://remoteURL/databaseName"/>

我已将此添加到我项目中的web.xml：

<!-- Setting up DBCP connection pooling as suggested by   http://www.onjava.com/2006/04/19/database-connection-pooling-with-tomcat.html-->
<listener>
    <listener-class> com.hastha.maperp.util.DBCPoolingListener</listener-class>
</listener>
<resource-ref>
    <description> DB Connection Pooling</description>
      <res-ref-name> jdbc/remoteDB</res-ref-name>
      <res-type> javax.sql.DataSource</res-type>
      <res-auth> Container</res-auth>
</resource-ref>

我得到this error when I try to start Tomcat from Eclipse。我应该设置什么docbase 值才能让它工作？

另外，目前我有一个从ServletContextListener接收DataSource对象的类，有没有更好的方法：

 package com.hastha.maperp.util;
import org.apache.tomcat.jdbc.pool.DataSource;

public class DataSourceFactory 

  public static DataSource ds;

这是错误：

Oct 30, 2014 12:29:08 PM org.apache.catalina.core.StandardContext resourcesStart
SEVERE: Error starting static Resources
java.lang.IllegalArgumentException: Document base C:\Users\Vamsi\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\webapps\dbcp does not exist or is not a readable directory
    at org.apache.naming.resources.FileDirContext.setDocBase(FileDirContext.java:136)
    at org.apache.catalina.core.StandardContext.resourcesStart(StandardContext.java:5089)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5269)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Oct 30, 2014 12:29:08 PM org.apache.catalina.core.ContainerBase startInternal
SEVERE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/dbcp]]
    at java.util.concurrent.FutureTask.report(Unknown Source)
    at java.util.concurrent.FutureTask.get(Unknown Source)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:799)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/dbcp]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    ... 6 more
Caused by: org.apache.catalina.LifecycleException: Error in resourceStart()
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5270)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 6 more

Oct 30, 2014 12:29:09 PM org.apache.catalina.core.ContainerBase startInternal
SEVERE: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
    at java.util.concurrent.FutureTask.report(Unknown Source)
    at java.util.concurrent.FutureTask.get(Unknown Source)
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:731)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
    at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
    at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:799)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 6 more

Oct 30, 2014 12:29:09 PM org.apache.catalina.startup.Catalina start
SEVERE: The required Server component failed to start so Tomcat is unable to start.
org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8105]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:689)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:731)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 7 more
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 9 more
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 11 more

Oct 30, 2014 12:29:09 PM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["http-bio-8180"]
Oct 30, 2014 12:29:09 PM org.apache.coyote.AbstractProtocol pause
INFO: Pausing ProtocolHandler ["ajp-bio-8109"]
Oct 30, 2014 12:29:09 PM org.apache.catalina.core.StandardService stopInternal
INFO: Stopping service Catalina
Oct 30, 2014 12:29:09 PM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["http-bio-8180"]
Oct 30, 2014 12:29:09 PM org.apache.coyote.AbstractProtocol destroy
INFO: Destroying ProtocolHandler ["ajp-bio-8109"]
Oct 30, 2014 12:29:10 PM org.apache.catalina.core.StandardContext listenerStop
SEVERE: Exception sending context destroyed event to listener instance of class com.hastha.maperp.util.DBCPoolingListener
java.lang.ClassCastException: org.apache.tomcat.dbcp.dbcp.BasicDataSource cannot be cast to org.apache.tomcat.jdbc.pool.DataSource
    at com.hastha.maperp.util.DBCPoolingListener.contextDestroyed(DBCPoolingListener.java:23)
    at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:5014)
    at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5659)
    at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
    at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1575)
    at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1564)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Oct 30, 2014 12:29:10 PM org.apache.catalina.deploy.NamingResources cleanUp
WARNING: Failed to retrieve JNDI naming context for container [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/dbcp]] so no cleanup was performed for that container
javax.naming.NamingException: No naming context bound to this class loader
    at org.apache.naming.ContextBindings.getClassLoader(ContextBindings.java:350)
    at org.apache.catalina.deploy.NamingResources.cleanUp(NamingResources.java:985)
    at org.apache.catalina.deploy.NamingResources.stopInternal(NamingResources.java:968)
    at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
    at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5676)
    at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:272)
    at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:1041)
    at org.apache.catalina.core.ContainerBase.destroyInternal(ContainerBase.java:1234)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:1041)
    at org.apache.catalina.core.ContainerBase.destroyInternal(ContainerBase.java:1234)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:593)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:821)
    at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
    at org.apache.catalina.startup.Catalina.start(Catalina.java:693)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:321)
    at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:455)

【问题讨论】：

在您的问题中发布错误。

寻求调试帮助的问题（“为什么这段代码不起作用？”）必须包括所需的行为、特定的问题或错误以及重现它所需的最短代码在问题本身。没有明确的问题陈述的问题对其他读者没有用处。见How to create a Minimal, Complete, and Verifiable example。

错误已经出现as a pastebin in the line I get this error when I try to start Tomcat from Eclipse。我也完整粘贴了。

【参考方案1】：

尝试创建文件context.xml 并写入所有配置并将其放入META-INF 文件夹中。 sample

【讨论】：

，我可以启动服务器，也删除了<listener>，而是尝试使用Resource in order to obtain the DataSource,I get this error