类加载资源路径在不同os下的差别

java获得类所在的路径的根，出现了不同平台的差异
System.out.println(new UtilTools().getClass().getResource(""));
System.out.println(new UtilTools().getClass().getResource("."));
System.out.println(new UtilTools().getClass().getResource(".."));
System.out.println(new UtilTools().getClass().getResource("/"));
结果如下：重点是第四个
windows
file:/D:/workspace/fbDnsLogNew/web/WEB-INF/classes/com/firebow/common/service/
file:/D:/workspace/fbDnsLogNew/web/WEB-INF/classes/com/firebow/common/service/
file:/D:/workspace/fbDnsLogNew/web/WEB-INF/classes/com/firebow/common/
file:/D:/workspace/fbDnsLogNew/web/WEB-INF/classes/
linux
file:/usr/app/apache-tomcat-6.0.20/webapps/ROOT/WEB-INF/classes/com/firebow/common/service/
file:/usr/app/apache-tomcat-6.0.20/webapps/ROOT/WEB-INF/classes/com/firebow/common/service/
file:/usr/app/apache-tomcat-6.0.20/webapps/ROOT/WEB-INF/classes/com/firebow/common/
file:/root/