java程序验证用户名密码和验证码登录的小例子

package Study02;
import java.util.Random;
import java.util.Scanner;
public class test {
	static String NAME="jie";
	static String PASS="123";
	public static void main(String[] args) {
		//输入用户名和密码
		//每次登陆生成验证码
		//System.out.println(1==2);
		Scanner sc =new Scanner(System.in); 
		test ts=new test();
		while(true){
			System.out.println("请输入用户名：");
			String name=sc.next();
			System.out.println("请输入密码：");
			String pass=sc.next();
			//临时变量temp记录随机码
			String temp= ts.suijishu();
			System.out.println("请输入验证码"+temp);
			String yzm=sc.next();
			//验证码正确
			if(yzm.equalsIgnoreCase(temp)){
				if(name.equals(NAME)&&pass.equals(PASS)){
					System.out.println("登陆成功！");
					break;
				}
				else{
					System.out.println("用户名或密码错误！");
				}
			}
			else{
				System.out.println("验证码错误！");
			}
		}
	}
	//生成随机数验证码
	public static String suijishu(){
		Random rds=new Random();
		char neirong[]={'1','2','3','4','5','6','7','8','9','0','a','b','c','d','e','A','B','C','D','E'};
		String code="";
		for(int i=0;i<6;i++){
			int tmp=rds.nextInt(neirong.length);
			code=code+neirong[tmp];
		}
		return code;
	}
}