자바 랜덤 문자+숫자 8자리

package sele;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Random;

public class RandomTest {

	public String getRndId() {
		Random rnd=new Random();
		List<String> list=new ArrayList<>();
		
		list.add(String.valueOf(rnd.nextInt(10)));
		list.add(String.valueOf(rnd.nextInt(10)));
		list.add(String.valueOf(rnd.nextInt(10)));
		list.add(String.valueOf(rnd.nextInt(10)));
		
		char c='a';
		c=((char)((int)(Math.random()*26)+97));
		list.add(String.valueOf(c));
		c=((char)((int)(Math.random()*26)+97));
		list.add(String.valueOf(c));
		c=((char)((int)(Math.random()*26)+97));
		list.add(String.valueOf(c));
		c=((char)((int)(Math.random()*26)+97));
		list.add(String.valueOf(c));
		
		Collections.shuffle(list);
		System.out.println(list);
		
		StringBuffer sb=new StringBuffer();
		for (String s : list) {
			sb.append(s);
		}
		return sb.toString();
	}
	
	
	public static void main(String[] args) {
		RandomTest r=new RandomTest();
		String id=r.getRndId();
		System.out.println("id="+id);

	}

}

결과:

[8, o, 8, h, 2, r, u, 5]
id=8o8h2ru5