java如何随机产生一个字母或数字 java怎么随机产生字母

 

方法一：

public class RandomTest extends TestCase {   
    public void testRandom1() throws Exception {   
        String s = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";   
        char[] c = s.toCharArray();   
        Random random = new Random();   
        for( int i = 0; i < 8; i ++) {   
            System.out.println(c[random.nextInt(c.length)]);   
        }   
    }   
}

方法二：

public void testRandom2() throws Exception {   
    Random random = new Random();   
    for( int i = 0; i < 8; i ++) {   
        int choice = random.nextInt(2) % 2 == 0 ? 65 : 97; // 取得大写还是小写   
        System.out.println((char)(choice + random.nextInt(26)));   
    }   
}