JSP+Java+properties+FileInputStream文件读写，JSP页面读取properties文件

String realPath = request.getRealPath("WEB-INF/classes/com/properties/devicetype.properties");

        Properties props = new Properties();
        ArrayList al = new ArrayList();
            try {
             InputStream in = new BufferedInputStream (new FileInputStream(realPath));
             props.load(in);
                Enumeration en = props.propertyNames();
                
                
                 while (en.hasMoreElements()) {
                  String key = (String) en.nextElement();
                        String Property = props.getProperty (key);
                        al.add(Property);
                        //System.out.println(key+Property);
                    }
            } catch (Exception e) {
             e.printStackTrace();
            }