404在浏览器中访问tomcat时出错

当我试图访问

http://myhost:8080/manager/html

它只返回空页。在文件

/var/lib/tomcat7/logs/localhost\u access\u log.2014-04-16.txt中，我可以看到如下行：

XXX.XXX.XXX.XXX - - [16/Apr/2014:13:43:53 -0400] "GET /manager/html HTTP/1.1" 404 -

有什么不对劲吗

更新
这是我在卡塔琳娜找到的

SEVERE: Error deploying web application directory /var/lib/tomcat7/webapps/ROOT
Apr 16, 2014 3:01:51 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-bio-8080"]
Apr 16, 2014 3:01:51 PM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 610 ms
Apr 16, 2014 3:01:51 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Apr 16, 2014 3:01:51 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.26
Apr 16, 2014 3:01:51 PM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor /etc/tomcat7/Catalina/localhost/manager.xml
Apr 16, 2014 3:01:52 PM org.apache.catalina.core.ContainerBase addChildInternal
SEVERE: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/manager]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:895)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:649)
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1581)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NoSuchMethodError: javax.servlet.ServletContext.getSessionCookieConfig()Ljavax/servlet/SessionCookieConfig;
    at org.apache.catalina.deploy.WebXml.configureContext(WebXml.java:1309)
    at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1310)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:855)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:345)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5161)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 10 more
Apr 16, 2014 3:01:52 PM org.apache.catalina.startup.HostConfig deployDescriptor
SEVERE: Error deploying configuration descriptor /etc/tomcat7/Catalina/localhost/manager.xml
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/manager]]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:898)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:649)
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1581)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask.run(FutureTask.java:262)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)

是的，我已经尝试了Joe的建议，但它对我不起作用，我仍然得到了同样的例外。好吧，看起来你在etomcat安装中出了问题，因为它不再找到合适的Servlet 3.0类-我建议完全删除Tomcat，重新安装，重新部署。哈，重新安装很有帮助。谢谢。