一案例要求：

二代码实现：

Ⅰ

package 重修;

import java.util.Random;
import java.util.Scanner;

public class first {
    public static void main(String[] args) {
        javabean s1=new javabean("张世杰","5201314");
        Scanner sc=new Scanner(System.in);
        int i=1;
        while (true) {
            System.out.print("请输入登录名:");
            String a=sc.next();
            System.out.print("请输入密码:");
            String b=sc.next();
            javabean s2=new javabean(a,b);
            javabeanoperate op=new javabeanoperate(s1.getLandmark(), s1.getCard());
            Boolean m;
            m=op.panduan(s2.getLandmark(),s2.getCard());
            if (m==true) {
                System.out.println("登录成功");break;
            }
            else {
                System.out.println("登录失败，登陆名或密码错误");
                System.out.println("请再次输入,您还有"+(3-i)+"次机会");
                i++;
            }
        }
    }
}

Ⅱ

package 重修;

public class javabean {
    private String landmark;
    private String card;

    public javabean() {
    }
    public javabean(String landmark, String card) {
        this.landmark = landmark;
        this.card = card;
    }

    public String getLandmark() {
        return landmark;
    }

    public void setLandmark(String landmark) {
        this.landmark = landmark;
    }

    public String getCard() {
        return card;
    }

    public void setCard(String card) {
        this.card = card;
    }
}

Ⅲ

    private String a;
    private String b;

    public javabeanoperate() {
    }

    public javabeanoperate(String a, String b) {
        this.a = a;
        this.b = b;
    }
    public Boolean panduan(String a, String b){
        if (this.a.equals(a)){
            if (this.b.equals(b)) return true;
            else  return false;
        }
        return false;
    }
}

三运行结果：