产生随机String

public static String getRandomString(int length){String str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";Random random = new Random();StringBuffer sb = new StringBuffer();for(int i=0; i<length; i++){int number = random.nextInt(62);sb.append(str.charAt(number));}return sb.toString();}

public static String getRandomString2(int length){String str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";Random random = new Random();StringBuffer sb = new StringBuffer();for(int i=0; i<length; i++){int number = random.nextInt(3);long result = 0;switch(number){case 0:result = Match.round(Math.random() * 25 + 65); //大些字母sb.append(String.valueOf((char)result));break;case 1:result = Match.round(Math.random() * 25 + 97); //大些字母sb.append(String.valueOf((char)result));break;case 2:sb.append(String.valueOf(new Random().nextInt(10)));break;}}return sb.toString();}