<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC
"-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN"
"http://getahead.org/dwr/dwr20.dtd">
报错：
Referenced file contains errors (http://www.getahead.ltd.uk/dwr/dwr20.dtd). For more information, right click on the message in the Problems View and
select "Show Details..."
解决方法：
是因为http://www.getahead.ltd.uk/dwr/dwr20.dtd已经不存在了，改成http://directwebremoting.org/schema/dwr20.dtd即可
