java利用时间格式生成唯一文件名的方法

avascript/105320.html">java;">package com.demo; import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar; public class TimeString {   private String valueOfString(String str, int len) {    StringBuffer sb = new StringBuffer();    for (int i = 0; i < len - str.length(); i++) {      sb.append("0");    }    return (sb.length() == 0) ? (str) : (sb.toString() + str);  }     public String getDateFormat(){    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    return df.format(new Date());      }      public Date getDateFormat(String time){    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");    try {      return df.parse(time);    } catch (ParseException e) {            e.printStackTrace();    }     return null;  }   private String getTimeString(Calendar calendar) {       StringBuffer sb = new StringBuffer();    sb.append(String.valueOf(calendar.get(Calendar.YEAR)))        .append(this.valueOfString(String.valueOf(calendar.get(Calendar.MONTH) + 1),2))     .append(this.valueOfString(String.valueOf(calendar.get(Calendar.DAY_OF_MONTH)),2))     .append(this.valueOfString(String.valueOf(calendar.get(Calendar.HOUR_OF_DAY)),2))     .append(this.valueOfString(String.valueOf(calendar.get(Calendar.MINUTE)),2))     .append(this.valueOfString(String.valueOf(calendar.get(Calendar.SECOND)),2))     .append(this.valueOfString(String.valueOf(calendar.get(Calendar.MILLISECOND)),3));        return sb.toString();  }      public String getTimeString(String time){    Calendar calendar = new GregorianCalendar();    calendar.setTime(this.getDateFormat(time));    return this.getTimeString(calendar);  }     public String getTimeString(){    Calendar calendar = new GregorianCalendar();    return this.getTimeString(calendar);  }     public static void main(String[] args) {    TimeString ts = new TimeString();    System.out.println(ts.getTimeString());    System.out.println(ts.getTimeString("2015-4-30 8:51:52"));  }}

package com.demo; import java.io.File; public class Test16 {     public String getFileName(String path){    File file = new File(path);    if(file.exists()){      return this.getFileName(file.getParent()+File.separator+(new TimeString().getTimeString())+".png");    }    return path;  }     public static void main(String[] args) {    Test16 t = new Test16();    System.out.println(t.getFileName("D:/1.txt"));  } }