什么原因会使tomcat自动关闭？麻烦大家帮忙分析一下！ 谢谢
server.xml文件如下：

<?xml   version= "1.0 "   encoding= "UTF-8 "?>
<Server>
    <Listener   className= "org.apache.catalina.core.AprLifecycleListener "/>
    <Listener   className= "org.apache.catalina.mbeans.GlobalResourcesLifecycleListener "/>
    <Listener   className= "org.apache.catalina.storeconfig.StoreConfigLifecycleListener "/>
    <Listener   className= "org.apache.catalina.mbeans.ServerLifecycleListener "/>
    <GlobalNamingResources>
        <Environment
            name= "simpleValue "
            type= "java.lang.Integer "
            value= "30 "/>
        <Resource
            auth= "Container "
            description= "User   database   that   can   be   updated   and   saved "
            name= "UserDatabase "
            type= "org.apache.catalina.UserDatabase "
            pathname= "conf/tomcat-users.xml "
            factory= "org.apache.catalina.users.MemoryUserDatabaseFactory "/>
        <Resource
            name= "jdbc/connectDB "
            type= "javax.sql.DataSource "
            driverClassName= "net.sourceforge.jtds.jdbc.Driver "
            password= "tytymnty110110 "
            maxIdle= "2 "
            maxWait= "5000 "
            validationQuery= "3 "
            username= "sa "
            url= "jdbc:jtds:sqlserver://127.0.0.1:1433/airin_b2b "
            maxActive= "1000 "/>
    </GlobalNamingResources>
    <Service
            name= "Catalina ">
        <Connector
                port= "8081 "
                redirectPort= "8443 "
                minSpareThreads= "25 "
                connectionTimeout= "20000 "
                maxSpareThreads= "75 "
                maxThreads= "150 ">
        </Connector>
        <Connector
                port= "8009 "
                redirectPort= "8443 "
        &nbs