获取指定长度随机数和系统当前时间到毫秒

package org.fenixsoft.osgi.bundle;

import java.text.DateFormat;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import java.util.Random;

public class testTime {

public static String excute(int length)

{

StringBuffer buffer = new StringBuffer("0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ");

StringBuffer sb = new StringBuffer();

Random r = new Random();

int range = buffer.length();

for (int i = 0; i < length; i ++)

{

sb.append(buffer.charAt(r.nextInt(range)));

}

return sb.toString();

}

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

Calendar calendar = Calendar.getInstance();

calendar.add(Calendar.DATE,0);

Date date = calendar.getTime();

DateFormat df = new SimpleDateFormat("yyyyMMddHHmmssSSS");

String day=df.format(date);

System.out.println(day);

String res = excute(30);

System.out.println(res);

}

}