js获得文件根目录

function getRootPath(){
                //获取当前网址，如： http://localhost:8083/proj/meun.jsp
                var curWwwPath = window.document.location.href;
                //获取主机地址之后的目录，如： proj/meun.jsp
                var pathName = window.document.location.pathname;
                var pos = curWwwPath.indexOf(pathName);
                //获取主机地址，如： http://localhost:8083
                var localhostPath = curWwwPath.substring(0, pos);
                //获取带"/"的项目名，如：/proj
                var projectName = pathName.substring(0, pathName.substr(1).indexOf('/')+1);
                return(localhostPath + projectName);
            }