JAVA快速功能

 1、日期格式化
 Date date=new Date();
 //转换成时间格式12小时制
 SimpleDateFormat df_12=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");

 //转换成时间格式24小时制
 SimpleDateFormat df_24=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

 System.out.println("12小时制时间::"+df_12.format(date));
 System.out.println("24小时制时间::"+df_24.format(date));

 2、过滤文件名非法字符
 private static Pattern FilePattern = Pattern.compile("[\\\\/:*?\"<>|]");
 public static String filenameFilter(String str) {
     return str==null?null:FilePattern.matcher(str).replaceAll("");
 }  

 3、读取文件内容
 public static String readFile(String filePath) throws Exception{
     File file = new File(filePath);
     BufferedReader in = null;
     String result = "";
     String str = "";
     try {
         in = new BufferedReader(new FileReader(file));
         while((str = in.readLine()) != null){
             result += str;
     }
         in.close();
     } catch (Exception e) {
         e.printStackTrace();
     }
     return result;
 }