获得随机的英文字母（大小写）

public class Random {
	public static void main(String[] args) {
		StringBuffer sBuffer=new StringBuffer("");
		for (int i = 0; i < 20; i++) {
			char randomCharacter=getRandomCharacter();
			sBuffer.append(randomCharacter);
		}
		
		System.out.println(sBuffer.toString());
	}

	private static char getRandomCharacter() {
		// TODO Auto-generated method stub
		switch ((int)(Math.random()*2)) {
		case 0:
			return (char)(Math.random()*26+'A');

		case 1:
			return (char)(Math.random()*26+'a');
		}
		return 0;
	}
}