用java数组模拟登录和注册功能

package com.linkage.login;

import java.util.Scanner;

public class user {
// 存储用户名和密码
public static String arr1[] = new String[3];
public static String arr2[] = new String[3];
static int index = 0;

@SuppressWarnings("resource")
public static void main(String[] args) {
arr1[0] = "zhangsan";
arr2[0] = "zhang";
while (true) {
print();
Scanner scan = new Scanner(System.in);
System.out.println("请选择功能：");
String str = scan.next();
if (str.equals("1")) {
login();
} else if (str.equals("2")) {
register();
} else if (str.equals("0")) {
System.exit(0);
break;
} else if (str.equals("3")) {
show();
} else {
System.out.println("输入错误");
}
}
}

// 登录功能
@SuppressWarnings("resource")
public static void login() {

for (int i = 0; i < 3; i++) {
Scanner scan1 = new Scanner(System.in);
System.out.println("请输入用户名：");
String str1 = scan1.next();
Scanner scan2 = new Scanner(System.in);
System.out.println("请输入密码：");
String str2 = scan2.next();
for (int i1 = 0; i1 < arr2.length; i1++) {
if (str1.equals(arr1[i1]) && str2.equals(arr2[i1])) {
System.out.println("登录成功！");
return;
}
}
System.out.println("登录失败，请重新输入！");
}
}

// 注册功能
@SuppressWarnings("resource")
public static void register() {
Scanner scan1 = new Scanner(System.in);
System.out.println("请输入用户名：");
String str1 = scan1.next();
Scanner scan2 = new Scanner(System.in);
System.out.println("请输入密码：");
String str2 = scan2.next();

boolean flag = false;
for (int i = 0; i < arr1.length; i++) {
if (str1.equals(arr1[i])) {
System.out.println("用户名已存在");
flag = true;
}
}
if (flag == false) {
index++;
if (index < arr1.length) {
arr1[index] = str1;
arr2[index] = str2;
System.out.println("注册成功！");
} else {
add();
arr1[index] = str1;
arr2[index] = str2;
System.out.println("注册成功！");

}
}
}

// 显示用户信息
public static void show() {
for (int i = 0; i < arr1.length; i++) {

if (arr1[i] != null) {
System.out.println("用户名：" + arr1[i] + "," + "密码：" + arr2[i]
+ "\n");
}
}
}

// 增加数组长度
public static void add() {
String newarray1[] = new String[arr1.length + 3];
String newarray2[] = new String[arr1.length + 3];
System.arraycopy(arr1, 0, newarray1, 0, arr1.length);
System.arraycopy(arr2, 0, newarray2, 0, arr1.length);
arr1 = newarray1;
arr2 = newarray2;
show();
}

// 输入内容
public static void print() {
System.out.println("--------------------管理系统--------------------");
System.out
.println(" 1.登录功能 (login) ");
System.out
.println(" 2.注册功能(register) ");
System.out
.println(" 3.查看(show) ");
System.out
.println(" 0.退出(exit) ");
System.out.println("--------------------管理系统--------------------");
}
}