Java小型管理系统，文章中有源码，适合作为课程作业，个人小项目（中等）

package cn.tx1;
/**
 * ID  类别  账户  类型   余额  时间  备注
 */
public class Bills {
    private String name;
    private String account;
    private String type;
    private double total;
    private String time;
    private String desc;
    //全参构造器
    public Bills(String name, String account, String type, double total, String time, String desc) {
        this.name = name;
        this.account = account;
        this.type = type;
        this.total = total;
        this.time = time;
        this.desc = desc;
    }
    //无参构造器
    public Bills() {
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getAccount() {
        return account;
    }
    public void setAccount(String account) {
        this.account = account;
    }
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public double getTotal() {
        return total;
    }
    public void setTotal(double total) {
        this.total = total;
    }
    public String getTime() {
        return time;
    }
    public void setTime(String time) {
        this.time = time;
    }
    public String getDesc() {
        return desc;
    }
    public void setDesc(String desc) {
        this.desc = desc;
    }
}

package cn.tx1;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class MainMenu {
    //创建一个集合来存储
    static List<Bills> billsList=new ArrayList<>();
    //静态代码块，类加载的时候第一时间执行   “果然还是用到了”
    static {
        //String name, String account, String type, double total, String time, String desc
        billsList.add(new Bills("吃饭支出","建设银行","支出",122247,"2022-1-1","家庭聚餐"));
        billsList.add(new Bills("吃饭支出","农业银行","支出",111222,"2021-12-11","家庭聚餐"));
        billsList.add(new Bills("工资收入","农商银行","收入",927227,"2021-11-1","发工资"));
        billsList.add(new Bills("交通支出","交通银行","支出",999247,"2021-1-1","交通支出"));
        billsList.add(new Bills("买气球","建设银行","支出",222147,"2025-1-1","买气球"));
        billsList.add(new Bills("奖金收入","投资银行","收入",908227,"2021-1-1","奖金"));
    }
    public static void showMain(){
        System.out.println("--------随手记---------");
        System.out.println("1、添加账务  2、删除帐务  3、查询账务  4、退出系统");
        System.out.println("请输入功能序号【1-4】：");
    }
    public static void main(String[] args) {
        run();
    }
    public static void run(){
        showMain();
        //创建一个flag标志,循环条件，变量存在
        boolean flag=true;
        //创建扫描器
        Scanner sc=new Scanner(System.in);
        //获得输入的选项
        while (flag){
            int num=sc.nextInt();
            //判断1、2、3、4
            switch (num){
                case 1:
                    addBills();
                    break;
                case 2:
                    delBills();
                    break;
                case 3:
                    select();
                    break;
                case 4:
                    flag=false;
                    break;
                default:
                    System.out.println("请重新输入选项：");
            }
        }
        System.out.println("退出系统,拜拜！");
    }
    private static void delBills() {
        Scanner sc2=new Scanner(System.in);
        int id= sc2.nextInt();
        billsList.remove(id-1);
        System.out.println("删除成功！！");
        showMain();
    }
    private static void addBills() {
        Scanner sc2=new Scanner(System.in);
        Bills bills=new Bills();
        System.out.println("请输入类别：");
        bills.setName(sc2.next());
        System.out.println("请输入账户：");
        bills.setAccount(sc2.next());
        System.out.println("请输入收入支出类型：");
        bills.setType(sc2.next());
        System.out.println("请输入金额：：");
        bills.setTotal(sc2.nextInt());
        System.out.println("请输入时间：");
        bills.setTime(sc2.next());
        System.out.println("请输入备注：");
        bills.setDesc(sc2.next());
        billsList.add(bills);
        System.out.println("财务添加成功！");
    }
    /**
     * 三种查询
     *   1、查询所有
     *   2、按照时间区间来查询
     *   3、按照收入和支出的类型来查询
     */
    private static void select(){
        System.out.println("随手记>>账务查询");
        System.out.println("1、查询所有   2、按照时间区间来查询    3、按照收入和支出的类型来查询");
        //创建扫描器
        Scanner sc1=new Scanner(System.in);
        int num=sc1.nextInt();
        switch (num){
            case 1:
                selectAll();
                break;
            case 2:
                selectByData();
                break;
            case 3:
                selectByType();
                break;
//            default:
//                System.out.println("亲，请重新输入选项：");
        }
        //展示上一级的主菜单
        showMain();
    }
    private static void selectAll(){
        System.out.println("查询所有");
        print(billsList);
    }
    private static void selectByData(){
        //创建一个时间格式化对象      [格式化器]
        SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd");
        System.out.println("按照时间查询");
        System.out.println("随手记>>账务查询>>按照时间查询");
        //创建扫描器
        Scanner sc1=new Scanner(System.in);
        System.out.println("请输入开始时间：");
        String start=sc1.next();
        System.out.println("请输入结束时间：");
        String end=sc1.next();
        //stream 流
        List<Bills> billsList1 = billsList.stream().filter(bills -> {
            String time = bills.getTime();
            //把字符串解析成具体时间
            try {
                Date startData = format.parse(start);
                Date endData = format.parse(end);
                Date timeData = format.parse(time);
                if (timeData.before(endData) && timeData.after(startData)) {
                    return true;
                }
            } catch (ParseException e) {
                e.printStackTrace();
            }
            return false;
        }).collect(Collectors.toList());
        print(billsList1);
    }
    private static void selectByType(){
        System.out.println("按照类型查询");
        System.out.println("随手记>>账务查询>>收入和支出类型");
        System.out.println("请输入   收入或者支出");
        //创建扫描器
        Scanner sc1=new Scanner(System.in);
        String type=sc1.next();
        //收入还是支出
        //筛选一下集合中type时支出的元素    stream筛选   collectCollectors.toList():将流转换为集合
        List<Bills> billsList1 = billsList.stream().filter(bills -> {
            String type1 = bills.getType();
            return type1.equals(type);
        }).collect(Collectors.toList());
        print(billsList1);
        //filter 过滤    true要，false不要
//        stream.filter(bills -> {
//           String type1= bills.getType();
//           return type1.equals(type);
//        });
    }
    public static void print(List<Bills> billsList){
        System.out.println("ID\t\t类别\t\t\t账户\t\t\t类型\t\t金额\t\t\t\t时间\t\t\t\t备注");
        for (int i = 0; i < billsList.size(); i++) {
            Bills bills1=billsList.get(i);
            System.out.println(i+1+"\t\t"+bills1.getName()+"\t\t"+bills1.getAccount()+"\t\t"+bills1.getType()
            +"\t\t"+bills1.getTotal()+"\t\t"+bills1.getTime()+"\t\t"+bills1.getDesc());
        }
    }
}