java 10位13位時間戳 ，指定、隨機字符串

時間戳

long  sjc13 =  System.currentTimeMillis();//13位時間戳

long  sjc10=  System.currentTimeMillis()/1000;//10位時間戳

 

生成指定的隨機字符串，比如指定字符爲abcdef0123456789，傳入需要生成的位數。

	public static String getRandomString(int length) {
		//隨機字符串的隨機字符庫
		String keyString = "abcdef0123456789";
		StringBuilder sb = new StringBuilder();
		Random random = new Random();
		for (int i = 0; i < length; i++) {
			sb.append(keyString.charAt(random.nextInt(keyString.length())));
		}
		return sb.toString();
	} 

隨機字符串，傳入想要的位數即可，5、10、15、20等隨機生成大小寫數字字符串

public static String getRandomString2(int length) {
		//隨機字符串的隨機字符庫
		String keyString = "abcdefghijkmnopqrstuvwxyzABCDEFGHIJKLMNPQRSTUVWXYZ0123456789";
		StringBuilder sb = new StringBuilder();
		Random random = new Random();
		for (int i = 0; i < length; i++) {
			sb.append(keyString.charAt(random.nextInt(keyString.length())));
		}
		return sb.toString();
	}