Spring Boot RESTful API 开发与测试

2. 实体类定义

使用 JPA 注解映射数据库表结构。注意字段命名规范和 Getter/Setter 的生成。

import javax.persistence.*;

@Entity
@Table(name = "product")
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    private String productId;
    private String productName;
    private double price;
    private int sales;

    public Product() {}

    public Product(String productId, String productName, double price, int sales) {
        this.productId = productId;
        this.productName = productName;
        this.price = price;
        this.sales = sales;
    }

    // Getter and Setter methods omitted for brevity
    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
    public String getProductId() { return productId; }
    public void setProductId(String productId) { this.productId = productId; }
    public String getProductName() { return productName; }
    public void setProductName(String productName) { this.productName = productName; }
    public double getPrice() { return price; }
    public void setPrice(double price) { this.price = price; }
    public int getSales() { return sales; }
    public void setSales(int sales) { this.sales = sales; }

    @Override
    public String toString() {
        return "Product{" +
                "id=" + id +
                ", productId='" + productId + '\'' +
                ", productName='" + productName + '\'' +
                ", price=" + price +
                ", sales=" + sales +
                '}';
    }
}

3. 数据访问层 (Repository)

继承 JpaRepository 即可自动获得基础 CRUD 能力，还可以自定义查询方法。

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import java.util.List;

@Repository
public interface ProductRepository extends JpaRepository<Product, Long> {
    List<Product> findBySalesGreaterThan(int sales);
}

4. 业务逻辑层 (Service)

Service 层负责事务管理和复杂业务逻辑编排。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.util.List;

@Service
public class ProductService {
    @Autowired
    private ProductRepository productRepository;

    @Transactional
    public void addProduct(Product product) {
        productRepository.save(product);
    }

    @Transactional
    public void updateProduct(Product product) {
        productRepository.save(product);
    }

    @Transactional
    public void deleteProduct(Long id) {
        productRepository.deleteById(id);
    }

    @Transactional(readOnly = true)
    public List<Product> getAllProducts() {
        return productRepository.findAll();
    }

    @Transactional(readOnly = true)
    public List<Product> getTopSellingProducts(int topN) {
        List<Product> products = productRepository.findBySalesGreaterThan(0);
        products.sort((p1, p2) -> p2.getSales() - p1.getSales());
        if (products.size() > topN) {
            return products.subList(0, topN);
        }
        return products;
    }
}

5. 控制器层 (Controller)

使用 @RestController 和路径映射注解暴露 HTTP 接口。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import java.util.List;

@RestController
@RequestMapping("/api/products")
public class ProductController {
    @Autowired
    private ProductService productService;

    @GetMapping("/")
    public ResponseEntity<List<Product>> getAllProducts() {
        List<Product> products = productService.getAllProducts();
        return new ResponseEntity<>(products, HttpStatus.OK);
    }

    @PostMapping("/")
    public ResponseEntity<Void> addProduct(@RequestBody Product product) {
        productService.addProduct(product);
        return new ResponseEntity<>(HttpStatus.CREATED);
    }

    @PutMapping("/{id}")
    public ResponseEntity<Void> updateProduct(@PathVariable Long id, @RequestBody Product product) {
        product.setId(id);
        productService.updateProduct(product);
        return new ResponseEntity<>(HttpStatus.OK);
    }

    @DeleteMapping("/{id}")
    public ResponseEntity<Void> deleteProduct(@PathVariable Long id) {
        productService.deleteProduct(id);
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    }

    @GetMapping("/top-selling")
    public ResponseEntity<List<Product>> getTopSellingProducts(@RequestParam int topN) {
        List<Product> products = productService.getTopSellingProducts(topN);
        return new ResponseEntity<>(products, HttpStatus.OK);
    }
}

Spring Boot RESTful API 的测试

高质量的代码离不开完善的测试。Spring Boot 提供了丰富的测试支持，涵盖单元测试、集成测试和 Mock 测试。

单元测试

针对 Service 层逻辑进行独立验证，不启动完整的 Web 容器。

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.util.List;
import static org.assertj.core.api.Assertions.assertThat;

@SpringBootTest
class ProductServiceTests {
    @Autowired
    private ProductService productService;

    @Test
    void testAddProduct() {
        Product product = new Product("P006", "平板", 2000.0, 70);
        productService.addProduct(product);
        List<Product> products = productService.getAllProducts();
        assertThat(products).hasSize(6);
    }

    @Test
    void testUpdateProduct() {
        Product product = new Product("P001", "手机", 1500.0, 120);
        product.setId(1L);
        productService.updateProduct(product);
        List<Product> products = productService.getAllProducts();
        assertThat(products.get(0).getPrice()).isEqualTo(1500.0);
    }

    @Test
    void testDeleteProduct() {
        productService.deleteProduct(2L);
        List<Product> products = productService.getAllProducts();
        assertThat(products).hasSize(4);
    }

    @Test
    void testGetTopSellingProducts() {
        List<Product> topSellingProducts = productService.getTopSellingProducts(3);
        assertThat(topSellingProducts).hasSize(3);
        assertThat(topSellingProducts.get(0).getProductId()).isEqualTo("P004");
        assertThat(topSellingProducts.get(1).getProductId()).isEqualTo("P005");
        assertThat(topSellingProducts.get(2).getProductId()).isEqualTo("P001");
    }
}

集成测试

模拟真实 HTTP 请求，测试整个应用栈的交互。

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.server.LocalServerPort;
import java.util.List;
import static org.assertj.core.api.Assertions.assertThat;

@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
class ProductControllerTests {
    @LocalServerPort
    private int port;

    @Autowired
    private TestRestTemplate restTemplate;

    @Test
    void testGetAllProducts() {
        List<Product> products = restTemplate.getForObject("http://localhost:" + port + "/api/products/", List.class);
        assertThat(products).hasSize(5);
    }

    @Test
    void testAddProduct() {
        Product product = new Product("P006", "平板", 2000.0, 70);
        restTemplate.postForEntity("http://localhost:" + port + "/api/products/", product, Void.class);
        List<Product> products = restTemplate.getForObject("http://localhost:" + port + "/api/products/", List.class);
        assertThat(products).hasSize(6);
    }

    @Test
    void testUpdateProduct() {
        Product product = new Product("P001", "手机", 1500.0, 120);
        restTemplate.put("http://localhost:" + port + "/api/products/1", product);
        List<Product> products = restTemplate.getForObject("http://localhost:" + port + "/api/products/", List.class);
        assertThat(products.get(0).getPrice()).isEqualTo(1500.0);
    }

    @Test
    void testDeleteProduct() {
        restTemplate.delete("http://localhost:" + port + "/api/products/2");
        List<Product> products = restTemplate.getForObject("http://localhost:" + port + "/api/products/", List.class);
        assertThat(products).hasSize(4);
    }

    @Test
    void testGetTopSellingProducts() {
        List<Product> topSellingProducts = restTemplate.getForObject("http://localhost:" + port + "/api/products/top-selling?topN=3", List.class);
        assertThat(topSellingProducts).hasSize(3);
        assertThat(topSellingProducts.get(0).getProductId()).isEqualTo("P004");
        assertThat(topSellingProducts.get(1).getProductId()).isEqualTo("P005");
        assertThat(topSellingProducts.get(2).getProductId()).isEqualTo("P001");
    }
}

Mock 测试

使用 MockMvc 隔离外部依赖，专注于 Controller 层的输入输出验证。

import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;
import java.util.Arrays;
import java.util.List;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.*;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@WebMvcTest(ProductController.class)
class ProductControllerMockTests {
    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private ProductService productService;

    @Test
    void testGetAllProducts() throws Exception {
        List<Product> products = Arrays.asList(
            new Product("P001", "手机", 1000.0, 100),
            new Product("P002", "电脑", 5000.0, 50),
            new Product("P003", "电视", 3000.0, 80),
            new Product("P004", "手表", 500.0, 200),
            new Product("P005", "耳机", 300.0, 150)
        );
        when(productService.getAllProducts()).thenReturn(products);
        mockMvc.perform(get("/api/products/"))
               .andExpect(status().isOk())
               .andExpect(content().contentType(MediaType.APPLICATION_JSON))
               .andExpect(jsonPath("$[0].productId").value("P001"));
        verify(productService, times(1)).getAllProducts();
    }

    @Test
    void testAddProduct() throws Exception {
        Product product = new Product("P006", "平板", 2000.0, 70);
        doNothing().when(productService).addProduct(any(Product.class));
        mockMvc.perform(post("/api/products/")
                .contentType(MediaType.APPLICATION_JSON)
                .content("{\"productId\":\"P006\",\"productName\":\"平板\",\"price\":2000.0,\"sales\":70}"))
               .andExpect(status().isCreated());
        verify(productService, times(1)).addProduct(any(Product.class));
    }

    @Test
    void testUpdateProduct() throws Exception {
        Product product = new Product("P001", "手机", 1500.0, 120);
        doNothing().when(productService).updateProduct(any(Product.class));
        mockMvc.perform(put("/api/products/1")
                .contentType(MediaType.APPLICATION_JSON)
                .content("{\"id\":1,\"productId\":\"P001\",\"productName\":\"手机\",\"price\":1500.0,\"sales\":120}"))
               .andExpect(status().isOk());
        verify(productService, times(1)).updateProduct(any(Product.class));
    }

    @Test
    void testDeleteProduct() throws Exception {
        doNothing().when(productService).deleteProduct(anyLong());
        mockMvc.perform(delete("/api/products/2"))
               .andExpect(status().isNoContent());
        verify(productService, times(1)).deleteProduct(anyLong());
    }

    @Test
    void testGetTopSellingProducts() throws Exception {
        List<Product> topSellingProducts = Arrays.asList(
            new Product("P004", "手表", 500.0, 200),
            new Product("P005", "耳机", 300.0, 150),
            new Product("P001", "手机", 1000.0, 100)
        );
        when(productService.getTopSellingProducts(3)).thenReturn(topSellingProducts);
        mockMvc.perform(get("/api/products/top-selling?topN=3"))
               .andExpect(status().isOk())
               .andExpect(content().contentType(MediaType.APPLICATION_JSON))
               .andExpect(jsonPath("$[0].productId").value("P004"));
        verify(productService, times(1)).getTopSellingProducts(3);
    }
}

Spring Boot RESTful API 的认证与授权

生产环境中的接口必须考虑安全性，防止未授权访问。

Spring Security 基础认证

Spring Security 提供了强大的安全框架，支持基于角色的访问控制。

依赖配置：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-security</artifactId>
</dependency>

安全配置示例：

import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.crypto.password.NoOpPasswordEncoder;

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(AuthenticationManagerBuilder auth) throws Exception {
        auth.inMemoryAuthentication()
            .passwordEncoder(NoOpPasswordEncoder.getInstance())
            .withUser("admin").password("admin123").roles("ADMIN")
            .and()
            .withUser("user").password("user123").roles("USER");
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests()
            .antMatchers("/api/products/top-selling").hasRole("ADMIN")
            .antMatchers("/api/products/**").hasRole("USER")
            .and().httpBasic();
    }
}

JWT 无状态认证

对于前后端分离架构，JWT（JSON Web Token）是更常用的方案。

核心组件：

1. JwtUtil：负责生成和解析 Token。
2. JwtRequestFilter：拦截请求，验证 Token 有效性。
3. SecurityConfig：配置无状态会话模式。

JwtUtil 工具类：

import io.jsonwebtoken.Claims;
import io.jsonwebtoken.Jwts;
import io.jsonwebtoken.SignatureAlgorithm;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.function.Function;

@Component
public class JwtUtil {
    @Value("${jwt.secret}")
    private String secret;

    @Value("${jwt.expiration}")
    private Long expiration;

    public String extractUsername(String token) {
        return extractClaim(token, Claims::getSubject);
    }

    public Date extractExpiration(String token) {
        return extractClaim(token, Claims::getExpiration);
    }

    public <T> T extractClaim(String token, Function<Claims, T> claimsResolver) {
        final Claims claims = extractAllClaims(token);
        return claimsResolver.apply(claims);
    }

    private Claims extractAllClaims(String token) {
        return Jwts.parser().setSigningKey(secret).parseClaimsJws(token).getBody();
    }

    private Boolean isTokenExpired(String token) {
        return extractExpiration(token).before(new Date());
    }

    public String generateToken(String username) {
        Map<String, Object> claims = new HashMap<>();
        return createToken(claims, username);
    }

    private String createToken(Map<String, Object> claims, String subject) {
        return Jwts.builder()
                .setClaims(claims)
                .setSubject(subject)
                .setIssuedAt(new Date(System.currentTimeMillis()))
                .setExpiration(new Date(System.currentTimeMillis() + expiration * 1000))
                .signWith(SignatureAlgorithm.HS256, secret)
                .compact();
    }

    public Boolean validateToken(String token, String username) {
        final String extractedUsername = extractUsername(token);
        return (extractedUsername.equals(username) && !isTokenExpired(token));
    }
}

配置文件 application.properties：

# JWT 配置
jwt.secret=mysecret
jwt.expiration=3600

实际应用场景

在实际项目中，RESTful API 广泛应用于商品管理、订单处理、用户中心等场景。结合上述技术栈，可以快速搭建起高可用、易维护的后端服务。

例如，通过 ProductApplication 启动服务后，访问 http://localhost:8080/api/products/ 即可获取产品列表，而 /api/products/top-selling?topN=3 则返回销量前三的商品。配合安全配置，不同角色用户可访问不同级别的接口。

总结

Spring Boot RESTful API 开发涉及资源定义、HTTP 方法映射、分层架构实现及自动化测试。核心在于利用 @RestController 注解构建控制器，结合 JPA 处理数据持久化，并通过单元测试、集成测试与 Mock 验证逻辑正确性。安全方面需集成 Spring Security 或 JWT 进行认证授权，确保接口访问受控。实际应用中可灵活组合这些技术栈，快速构建高可用、易维护的后端服务。