//获取到http
System.out.print(httpRequest.getScheme()+"<br/>");
//获取到localhost (服务器名)
System.out.print(httpRequest.getServerName()+"<br/>");
//获取到8080 (服务器端口)
System.out.print(httpRequest.getServerPort()+"<br/>");
//获取到/epet (项目路径)
System.out.print(httpRequest.getContextPath()+"<br/>");
//获取到/test/index.jsp (服务路径名)
System.out.print(httpRequest.getServletPath()+"<br/>");
//获取到/epet/test/index.jsp(请求地址)
System.out.print(httpRequest.getRequestURI()+"<br/>");