Java里如何实现简易财务预算与支出管理_财务预算支出管理项目开发方法说明

public class Expense {
    private double amount;
    private String category;
    private String date;  // 可用 LocalDate 更好
    private String description;

    public Expense(double amount, String category, String date, String description) {
        this.amount = amount;
        this.category = category;
        this.date = date;
        this.description = description;
    }

    // Getter 方法（必要时也可加 Setter）
    public double getAmount() { return amount; }
    public String getCategory() { return category; }
    public String getDate() { return date; }
    public String getDescription() { return description; }
}

public class Budget {
    private String category;
    private double limit;

    public Budget(String category, double limit) {
        this.category = category;
        this.limit = limit;
    }

    public String getCategory() { return category; }
    public double getLimit() { return limit; }
    public void setLimit(double limit) { this.limit = limit; }
}

import java.util.*;

public class FinanceManager {
    private List<Expense> expenses;
    private Map<String, Budget> budgets;  // 按类别存储预算

    public FinanceManager() {
        expenses = new ArrayList<>();
        budgets = new HashMap<>();
    }

    public void addExpense(Expense expense) {
        expenses.add(expense);
    }

    public void setBudget(String category, double limit) {
        budgets.put(category, new Budget(category, limit));
    }

    public double getTotalExpenseByCategory(String category) {
        return expenses.stream()
                .filter(e -> e.getCategory().equals(category))
                .mapToDouble(Expense::getAmount)
                .sum();
    }

    public void checkBudgetAlerts() {
        for (Budget budget : budgets.values()) {
            String category = budget.getCategory();
            double limit = budget.getLimit();
            double spent = getTotalExpenseByCategory(category);
            if (spent >= limit * 0.8 && spent < limit) {
                System.out.println("⚠️  注意：[" + category + "] 类别支出已达预算的80% (" + spent + "/" + limit + ")");
            } else if (spent >= limit) {
                System.out.println("❌ 警告：[" + category + "] 类别已超出预算！(" + spent + ">" + limit + ")");
            }
        }
    }
}

try (BufferedReader reader = new BufferedReader(new FileReader(file))) {
    String line;
    while ((line = reader.readLine()) != null) {
        String[] parts = line.split(",");
        if (parts.length == 4) {
            double amount = Double.parseDouble(parts[0]);
            String category = parts[1];
            String date = parts[2];
            String desc = parts[3];
            expenses.add(new Expense(amount, category, date, desc));
        }
    }
}

<H3>4. 添加用户交互界面（控制台版）</H3>
<p>使用 Scanner 实现简单菜单操作：</p>
```java
public static void main(String[] args) {
    FinanceManager fm = new FinanceManager();
    Scanner sc = new Scanner(System.in);

    while (true) {
        System.out.println("\n=== 财务管理菜单 ===");
        System.out.println("1. 添加支出");
        System.out.println("2. 设置预算");
        System.out.println("3. 查看统计");
        System.out.println("4. 检查预算提醒");
        System.out.println("5. 退出");
        System.out.print("请选择：");

        int choice = Integer.parseInt(sc.nextLine());

        switch (choice) {
            case 1:
                // 输入并添加支出
                break;
            case 2:
                // 设置预算
                break;
            case 3:
                // 打印各类别总支出
                break;
            case 4:
                fm.checkBudgetAlerts();
                break;
            case 5:
                System.out.println("再见！");
                return;
            default:
                System.out.println("无效选择");
        }
    }
}