本文目录导读：
我来为您介绍一个Java最小可行产品（MVP）案例，实现一个简单的任务管理应用。
项目结构
task-manager/
├── src/
│ └── main/java/com/example/
│ ├── model/Task.java
│ ├── service/TaskService.java
│ └── Main.java
└── pom.xmlMaven依赖 (pom.xml)
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>task-manager</artifactId>
<version>1.0</version>
<properties>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
</properties>
<dependencies>
<!-- Jackson for JSON processing -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.13.0</version>
</dependency>
</dependencies>
</project>
任务模型 (Task.java)
package com.example.model;
import java.time.LocalDateTime;
import java.util.Objects;
import java.util.UUID;
public class Task {
private String id;
private String title;
private String description;
private boolean completed;
private LocalDateTime createdAt;
private LocalDateTime updatedAt;
public Task() {
this.id = UUID.randomUUID().toString();
this.createdAt = LocalDateTime.now();
this.updatedAt = LocalDateTime.now();
this.completed = false;
}
public Task(String title, String description) {
this();
this.title = title;
this.description = description;
}
// Getters and Setters
public String getId() { return id; }
public void setId(String id) { this.id = id; }
public String getTitle() { return title; }
public void setTitle(String title) {
this.title = title;
this.updatedAt = LocalDateTime.now();
}
public String getDescription() { return description; }
public void setDescription(String description) {
this.description = description;
this.updatedAt = LocalDateTime.now();
}
public boolean isCompleted() { return completed; }
public void setCompleted(boolean completed) {
this.completed = completed;
this.updatedAt = LocalDateTime.now();
}
public LocalDateTime getCreatedAt() { return createdAt; }
public LocalDateTime getUpdatedAt() { return updatedAt; }
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
Task task = (Task) o;
return Objects.equals(id, task.id);
}
@Override
public int hashCode() {
return Objects.hash(id);
}
@Override
public String toString() {
return String.format("Task{id='%s', title='%s', completed=%s, createdAt=%s}",
id, title, completed, createdAt);
}
}
任务服务 (TaskService.java)
package com.example.service;
import com.example.model.Task;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import java.io.*;
import java.nio.file.*;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
public class TaskService {
private final Map<String, Task> tasks;
private final ObjectMapper objectMapper;
private static final String DATA_FILE = "tasks.json";
public TaskService() {
this.tasks = new ConcurrentHashMap<>();
this.objectMapper = new ObjectMapper();
this.objectMapper.registerModule(new JavaTimeModule());
loadTasks();
}
// 创建任务
public Task createTask(String title, String description) {
Task task = new Task(title, description);
tasks.put(task.getId(), task);
saveTasks();
return task;
}
// 获取所有任务
public List<Task> getAllTasks() {
return new ArrayList<>(tasks.values());
}
// 获取单个任务
public Optional<Task> getTask(String id) {
return Optional.ofNullable(tasks.get(id));
}
// 更新任务
public Optional<Task> updateTask(String id, String title, String description, Boolean completed) {
Task task = tasks.get(id);
if (task != null) {
if (title != null) task.setTitle(title);
if (description != null) task.setDescription(description);
if (completed != null) task.setCompleted(completed);
saveTasks();
return Optional.of(task);
}
return Optional.empty();
}
// 删除任务
public boolean deleteTask(String id) {
Task removed = tasks.remove(id);
if (removed != null) {
saveTasks();
return true;
}
return false;
}
// 搜索任务
public List<Task> searchTasks(String keyword) {
List<Task> result = new ArrayList<>();
String lowerKeyword = keyword.toLowerCase();
for (Task task : tasks.values()) {
if (task.getTitle().toLowerCase().contains(lowerKeyword) ||
task.getDescription().toLowerCase().contains(lowerKeyword)) {
result.add(task);
}
}
return result;
}
// 获取统计信息
public Map<String, Object> getStatistics() {
Map<String, Object> stats = new HashMap<>();
List<Task> allTasks = getAllTasks();
stats.put("total", allTasks.size());
stats.put("completed", allTasks.stream().filter(Task::isCompleted).count());
stats.put("pending", allTasks.stream().filter(t -> !t.isCompleted()).count());
return stats;
}
// 持久化到文件
private void saveTasks() {
try {
objectMapper.writerWithDefaultPrettyPrinter()
.writeValue(new File(DATA_FILE), getAllTasks());
} catch (IOException e) {
System.err.println("保存任务失败: " + e.getMessage());
}
}
// 从文件加载
private void loadTasks() {
File file = new File(DATA_FILE);
if (file.exists()) {
try {
List<Task> loadedTasks = objectMapper.readValue(
file,
new TypeReference<List<Task>>() {}
);
loadedTasks.forEach(task -> tasks.put(task.getId(), task));
} catch (IOException e) {
System.err.println("加载任务失败: " + e.getMessage());
}
}
}
}
主程序入口 (Main.java)
package com.example;
import com.example.model.Task;
import com.example.service.TaskService;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
public class Main {
private static final Scanner scanner = new Scanner(System.in);
private static final TaskService taskService = new TaskService();
public static void main(String[] args) {
System.out.println("=== 任务管理器 MVP ===");
System.out.println("最小可行产品 - 基于控制台的简单任务管理");
while (true) {
showMenu();
String choice = scanner.nextLine().trim();
if ("0".equals(choice)) {
System.out.println("谢谢使用，再见！");
break;
}
handleChoice(choice);
}
scanner.close();
}
private static void showMenu() {
System.out.println("\n请选择操作：");
System.out.println("1. 创建任务");
System.out.println("2. 查看所有任务");
System.out.println("3. 查看任务详情");
System.out.println("4. 更新任务");
System.out.println("5. 删除任务");
System.out.println("6. 搜索任务");
System.out.println("7. 查看统计信息");
System.out.println("0. 退出");
System.out.print("请输入选择: ");
}
private static void handleChoice(String choice) {
switch (choice) {
case "1":
createTask();
break;
case "2":
listAllTasks();
break;
case "3":
viewTaskDetails();
break;
case "4":
updateTask();
break;
case "5":
deleteTask();
break;
case "6":
searchTasks();
break;
case "7":
showStatistics();
break;
default:
System.out.println("无效选择，请重新输入");
}
}
private static void createTask() {
System.out.print("请输入任务标题: ");
String title = scanner.nextLine().trim();
System.out.print("请输入任务描述: ");
String description = scanner.nextLine().trim();
if (title.isEmpty()) {
System.out.println("标题不能为空！");
return;
}
Task task = taskService.createTask(title, description);
System.out.println("任务创建成功！ID: " + task.getId());
}
private static void listAllTasks() {
List<Task> tasks = taskService.getAllTasks();
if (tasks.isEmpty()) {
System.out.println("暂无任务");
return;
}
System.out.println("\n=== 任务列表 ===");
for (int i = 0; i < tasks.size(); i++) {
Task task = tasks.get(i);
String status = task.isCompleted() ? "[已完成]" : "[待完成]";
System.out.printf("%d. %s %s%n", i + 1, status, task.getTitle());
}
}
private static void viewTaskDetails() {
System.out.print("请输入任务ID: ");
String id = scanner.nextLine().trim();
taskService.getTask(id).ifPresentOrElse(
task -> {
System.out.println("\n=== 任务详情 ===");
System.out.println("ID: " + task.getId());
System.out.println("标题: " + task.getTitle());
System.out.println("描述: " + task.getDescription());
System.out.println("状态: " + (task.isCompleted() ? "已完成" : "待完成"));
System.out.println("创建时间: " + task.getCreatedAt());
System.out.println("更新时间: " + task.getUpdatedAt());
},
() -> System.out.println("任务不存在")
);
}
private static void updateTask() {
System.out.print("请输入要更新的任务ID: ");
String id = scanner.nextLine().trim();
System.out.print("新标题 (直接回车保持不变): ");
String title = scanner.nextLine().trim();
title = title.isEmpty() ? null : title;
System.out.print("新描述 (直接回车保持不变): ");
String description = scanner.nextLine().trim();
description = description.isEmpty() ? null : description;
System.out.print("是否完成? (y/n/直接回车保持不变): ");
String completeInput = scanner.nextLine().trim().toLowerCase();
Boolean completed = null;
if ("y".equals(completeInput)) completed = true;
else if ("n".equals(completeInput)) completed = false;
taskService.updateTask(id, title, description, completed)
.ifPresentOrElse(
task -> System.out.println("更新成功！"),
() -> System.out.println("更新失败，任务不存在")
);
}
private static void deleteTask() {
System.out.print("请输入要删除的任务ID: ");
String id = scanner.nextLine().trim();
System.out.print("确认删除? (y/n): ");
String confirm = scanner.nextLine().trim().toLowerCase();
if ("y".equals(confirm)) {
if (taskService.deleteTask(id)) {
System.out.println("删除成功！");
} else {
System.out.println("删除失败，任务不存在");
}
} else {
System.out.println("已取消删除");
}
}
private static void searchTasks() {
System.out.print("请输入搜索关键词: ");
String keyword = scanner.nextLine().trim();
List<Task> results = taskService.searchTasks(keyword);
if (results.isEmpty()) {
System.out.println("未找到匹配的任务");
return;
}
System.out.println("\n=== 搜索结果 ===");
for (Task task : results) {
String status = task.isCompleted() ? "[已完成]" : "[待完成]";
System.out.printf("- %s %s (ID: %s)%n", status, task.getTitle(), task.getId());
}
}
private static void showStatistics() {
Map<String, Object> stats = taskService.getStatistics();
System.out.println("\n=== 统计信息 ===");
System.out.println("总任务数: " + stats.get("total"));
System.out.println("已完成: " + stats.get("completed"));
System.out.println("待完成: " + stats.get("pending"));
long total = (long) stats.get("total");
if (total > 0) {
long completed = (long) stats.get("completed");
double completionRate = (double) completed / total * 100;
System.out.printf("完成率: %.1f%%%n", completionRate);
}
}
}
快速运行
# 编译 mvn clean compile # 运行 mvn exec:java -Dexec.mainClass="com.example.Main"
MVP核心功能
✅ CRUD操作：创建、读取、更新、删除任务
✅ 数据持久化：保存到JSON文件
✅ 搜索功能：按关键字搜索
✅ 统计信息：查看任务完成情况
✅ 友好的命令行界面：交互式操作
✅ 错误处理：基本的异常处理
这个MVP包含了任务管理应用的核心功能,可以直接运行使用，您可以根据需要扩展更多功能，如数据库支持、REST API、图形界面等。
