Struts+Mysql错误 问题困扰了好几天了。

MySQL用的是4.x几的，我的jar包是mysql-connector-java-3.1.13-bin.jar
程序运行1天后在Tomcat里报错。
我的Mysql数据库连接每次用完也都关闭了。struts-config.xml中配置数据源如下：
    <data-source key="mysql">
      <set-property property="driverClass" value="com.mysql.jdbc.Driver" />
      <set-property property="url" value="jdbc:mysql://localhost:3306/sdunion2006" />
      <set-property property="password" value="123" />
      <set-property property="user" value="root" />
      <set-property property="readOnly" value="false" />
      <set-property property="autoCommit" value="true" />
      <set-property property="loginTimeout" value="5000" />
    </data-source>
///////////////////////Tomcat异常////////////////////////
Last packet sent to the server was 47 ms ago.STACKTRACE:com.mysql.jdbc.CommunicationsException: Communications link failure due to under
lying exception:** BEGIN NESTED EXCEPTION **java.io.EOFExceptionSTACKTRACE:java.io.EOFException
        at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1934)
        at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2380)
        at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2909)
        at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1600)
        at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1695)
        at com.mysql.jdbc.Connection.execSQL(Connection.java:2998)
        at com.mysql.jdbc.Connection.setAutoCommit(Connection.java:4959)
        at org.apache.struts.legacy.GenericConnection.close(GenericConnection.ja
va:230)
        at finance.DB.close(DB.java:87)
        at finance.login.loginAction.execute(loginAction.java:65)
        at org.apache.struts.action.RequestProcessor.processActionPerform(Reques
tProcessor.java:484)
        at org.apache.struts.action.RequestProcessor.process(RequestProcessor.ja
va:274)
        at org.apache.struts.action.ActionServlet.process(ActionServlet.java:148
2)
        at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:525)        at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Appl
icationFilterChain.java:237)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationF
ilterChain.java:157)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperV
alve.java:214)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.StandardContextValve.invokeInternal(Standard
ContextValve.java:198)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextV
alve.java:152)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.j
ava:137)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.j
ava:118)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:102)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineVal
ve.java:109)
        at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValv
eContext.java:104)
        at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.jav
a:520)
        at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)        at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:16
0)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java
:799)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.proce
ssConnection(Http11Protocol.java:705)
        at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java
:577)
        at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadP
ool.java:683)
        at java.lang.Thread.run(Thread.java:534)
** END NESTED EXCEPTION **