更改xml的默认页不对

<?xml version="1.0" encoding="utf-8"?>

<web-app xmlns="http://java.sun.com/xml/ns/javaee"

  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee

                      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"

  version="3.0"

  metadata-complete="true">

<welcom-file-list>

        <welcom-file>haha.jsp</welcom-file>

    </welcom-file-list>

</web-app>

如题,haha.jsp和/haha.jsp都试过了 ,localhost/myhome默认的都打不开报错:

The requested resource is not available.

Apache Tomcat/7.0.79

有能看懂的同学吗