java怎么实现RESTful API 手把手教你搭建RESTful风格的接口服务

package com.example.demoapi.entity;
<p>public class User {
private Long id;
private String name;
private String email;</p><pre class='brush:java;toolbar:false;'>// 构造函数
public User() {}

public User(Long id, String name, String email) {
    this.id = id;
    this.name = name;
    this.email = email;
}

// Getter 和 Setter 方法
public Long getId() { return id; }
public void setId(Long id) { this.id = id; }

public String getName() { return name; }
public void setName(String name) { this.name = name; }

public String getEmail() { return email; }
public void setEmail(String email) { this.email = email; }

package com.example.demoapi.controller;
<p>import com.example.demoapi.entity.User;
import org.springframework.web.bind.annotation.*;</p><p>import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;</p><p>@RestController
@RequestMapping("/users")
public class UserController {</p><pre class='brush:java;toolbar:false;'>private List<User> users = new ArrayList<>();
private AtomicLong counter = new AtomicLong();

// 初始化一些测试数据
public UserController() {
    users.add(new User(counter.incrementAndGet(), "张三", "zhangsan@example.com"));
    users.add(new User(counter.incrementAndGet(), "李四", "lisi@example.com"));
}

// GET /users - 获取所有用户
@GetMapping
public List<User> getAllUsers() {
    return users;
}

// GET /users/{id} - 获取指定用户
@GetMapping("/{id}")
public User getUserById(@PathVariable Long id) {
    return users.stream()
            .filter(user -> user.getId().equals(id))
            .findFirst()
            .orElse(null);
}

// POST /users - 创建新用户
@PostMapping
public User createUser(@RequestBody User user) {
    user.setId(counter.incrementAndGet());
    users.add(user);
    return user;
}

// PUT /users/{id} - 更新用户
@PutMapping("/{id}")
public User updateUser(@PathVariable Long id, @RequestBody User updatedUser) {
    for (User user : users) {
        if (user.getId().equals(id)) {
            user.setName(updatedUser.getName());
            user.setEmail(updatedUser.getEmail());
            return user;
        }
    }
    return null;
}

// DELETE /users/{id} - 删除用户
@DeleteMapping("/{id}")
public String deleteUser(@PathVariable Long id) {
    boolean removed = users.removeIf(user -> user.getId().equals(id));
    return removed ? "删除成功" : "用户不存在";
}

{
    "name": "王五",
    "email": "wangwu@example.com"
}