参考文档：http://tomcat.apache.org/tomcat-7.0-doc/servletapi/javax/servlet/annotation/WebServlet.html
E.g. @WebServlet("/path")}
public class TestServlet extends HttpServlet ... {
E.g. @WebServlet(name="TestServlet", urlPatterns={"/path", "/alt"})
public class TestServlet extends HttpServlet ... {
