JAVA_SE基础——71.Random类制作随机验证码

public class Demo5 {
	public static void main(String[] args) {

		 char[] arr={'s','b','g','h','a','c'};
		StringBuilder sb=new StringBuilder();
		Random  random=new Random();
		for(int i=0;i<4;i++){
			int index=random.nextInt(arr.length);
			sb.append(arr[index]);
		}
		System.out.println("验证码:"+sb);
	} 

}