69 lines
2.0 KiB
Java
69 lines
2.0 KiB
Java
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package com.example.demo.service;
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import com.example.demo.model.User;
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import org.springframework.stereotype.Service;
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import java.util.ArrayList;
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import java.util.List;
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import java.util.concurrent.atomic.AtomicLong;
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import java.util.stream.Collectors;
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/**
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* 用户服务 - 业务逻辑层
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*
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* 学习点：
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* - @Service: 标记为服务层组件，自动注册为 Bean
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* - 依赖注入：Controller 通过 @Autowired 注入此服务
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* - 分层架构：Controller -> Service -> Repository
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*/
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@Service
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public class UserService {
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// 内存存储（演示用，实际项目用数据库）
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private final List<User> users = new ArrayList<>();
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private final AtomicLong idGenerator = new AtomicLong(1);
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public UserService() {
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// 初始化一些测试数据
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users.add(new User(idGenerator.getAndIncrement(), "张三", "zhangsan@example.com", 25));
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users.add(new User(idGenerator.getAndIncrement(), "李四", "lisi@example.com", 30));
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users.add(new User(idGenerator.getAndIncrement(), "王五", "wangwu@example.com", 28));
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}
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public List<User> findAll() {
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return new ArrayList<>(users);
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}
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public User findById(Long id) {
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return users.stream()
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.filter(u -> u.getId().equals(id))
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.findFirst()
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.orElse(null);
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}
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public List<User> findByName(String name) {
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return users.stream()
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.filter(u -> u.getName().contains(name))
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.collect(Collectors.toList());
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}
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public User save(User user) {
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if (user.getId() == null) {
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user.setId(idGenerator.getAndIncrement());
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users.add(user);
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} else {
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// 更新
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for (int i = 0; i < users.size(); i++) {
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if (users.get(i).getId().equals(user.getId())) {
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users.set(i, user);
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break;
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}
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}
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}
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return user;
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}
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public void delete(Long id) {
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users.removeIf(u -> u.getId().equals(id));
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}
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}
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