java_二维数组简单快递系统

public class Demo1 {

    public static void main(String[] args) {
        String express[][] = new String[0][3]; //定义快递二维数组
        String[][] arr; // 定义临时数组
        while (true) {
            System.out.println("==欢迎使用XXX快递柜===");
            System.out.println("请输入你的身份：1-快递员，2-用户");
            Scanner s = new Scanner(System.in);
            int i = s.nextInt();
            if (i == 1) {
                System.out.println("请选择操作：1-存快递 2-删除快递 3-修改快递信息 4-查看所有快递");
                int j = s.nextInt();
                switch (j) {


                // 1-存快递
                case 1:
                    System.out.println("请输入快递单号：");
                    String num = s.next();
                    System.out.println("请输入公司名称：");
                    String name = s.next();
                    Random ran = new Random();
                    String r = Integer.toString(ran.nextInt(1000));
                    System.out.println("快递已存入，取件码是：" + r);

                    arr = new String[express.length + 1][3];
                    for (int n = 0; n < express.length; n++) {
                        System.arraycopy(express, 0, arr, 0, express.length);
                    }
                    arr[arr.length - 1] = new String[] { num, name, r };
                    express = arr;
                    break;


                // 2-删除快递
                case 2:
                    arr = new String[express.length - 1][3];
                    System.out.println("请输入要删除的快递单号：");
                    String l = s.next();
                    for (int n = 0; n < express.length; n++) {
                        if (express[n][0].equals(l)) {
                            System.arraycopy(express, 0, arr, 0, n);
                            System.arraycopy(express, n + 1, arr, n, arr.length - n);
                            express = arr;
                            System.out.println("删除成功");
                            break;
                        } else if (n == express.length - 1) {
                            System.out.println("未找到快递");
                            break;
                        }

                    }
                    break;


                //3-修改快递信息
                case 3:
                    System.out.println("请输入要修改的快递单号：");
                    String o = s.next();
                    for (int n = 0; n < express.length; n++) {
                        if (express[n][0].equals(o)) {
                            System.out.println("请输入新的快递单号：");
                            String newnum = s.next();
                            express[n][0] = newnum;
                            System.out.println("请输入新的快递公司：");
                            String newname = s.next();
                            express[n][1] = newname;
                            System.out.println("修改成功");
                        } else if (i == express.length - 1) {
                            System.out.println("未找到快递");
                            break;
                        }                       
                    }
                    break;

                //  4-查看所有快递
                case 4:
                    System.out.println("----------------全部快递---------------");
                    System.out.println("快递号\t\t快递公司\t\t取件码");
                    for (int n = 0; n < express.length; n++) {
                        for (int m = 0; m < express[n].length; m++) {
                            System.out.print(express[n][m] + "\t\t");
                        }
                        System.out.println();
                    }
                    break;
                default:
                    System.out.println("输入有误！");
                }
                // 用户取件部分
            } else if (i == 2) {
                arr = new String[express.length - 1][3];
                System.out.println("请输入取件码：");
                String p = s.next();
                for (int n = 0; n < express.length; n++) {
                    if (express[n][2].equals(p)) {
                        System.arraycopy(express, 0, arr, 0, n);
                        System.arraycopy(express, n + 1, arr, n, arr.length - n);
                        express = arr;
                        System.out.println("取件成功");
                        break;
                    } else if (n == express.length - 1) {
                        System.out.println("未找到快递");
                        break;
                    }

                }

            } else {
                System.out.println("输入有误！");
            }
        }
    }

}