我就是按照提示创建了filter类，但是tomcat加载总是失败

INFO: validateJarFile(E:\Eclipse44Workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\WebUpload\WEB-INF\lib\servlet-api.jar) - jar not loaded. See Servlet Spec 3.0, section 10.7.2. Offending class: javax/servlet/Servlet.class
2015-2-1 22:24:06 org.apache.catalina.core.StandardContext filterStart
SEVERE: Exception starting filter FirstFilter
Throwable occurred: java.lang.ClassNotFoundException: com.imooc.filter.FirstFilter
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1720)

我就是按照提示创建了filter类，但是tomcat加载总是失败