Spring Boot RESTful API 开发全流程与测试实战

2. 实体层 (Entity)

定义数据模型，这里以 Product 为例。注意注解的使用和 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; }
}

3. 数据访问层 (Repository)

利用 Spring Data JPA 简化 SQL 操作，甚至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)

处理事务和业务规则，Controller 层不应直接操作数据库。

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. 控制层 (Controller)

暴露 HTTP 接口，使用 @RestController 配合路径映射注解。

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);
    }
}

测试策略：单元、集成与 Mock

代码写得再好，没有测试也是空中楼阁。Spring Boot 提供了丰富的测试支持，针对不同场景选择合适的测试方式至关重要。

单元测试

专注于 Service 层的逻辑验证，不启动完整容器，速度最快。

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);
    }
}

集成测试

需要启动完整的 Web 环境，模拟真实的 HTTP 请求，适合验证 Controller 与外部交互。

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);
    }
}

Mock 测试

当需要隔离依赖（如数据库或第三方服务）时，使用 MockMvc 配合 @MockBean 进行纯应用层测试，效率极高。

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 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 {
        when(productService.getAllProducts()).thenReturn(Arrays.asList());
        mockMvc.perform(get("/api/products/"))
               .andExpect(status().isOk())
               .andExpect(content().contentType(MediaType.APPLICATION_JSON));
        verify(productService, times(1)).getAllProducts();
    }
}

安全控制：认证与授权

生产环境的 API 必须考虑安全性。Spring Security 是最常用的框架，支持 Basic Auth 和 JWT 等多种模式。

Spring Security 基础认证

对于内部系统或简单场景，Basic Auth 足够使用。配置类中定义用户信息和权限规则。

import org.springframework.context.annotation.Configuration;
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(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

对于前后端分离项目，JWT（JSON Web Token）更为常见。它允许客户端携带凭证，服务端无需存储 Session。

核心流程包括：生成 Token、过滤器解析 Token、验证 Token 有效性。

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;

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

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

    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));
    }

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

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

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

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

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

配合 JwtRequestFilter 拦截请求并设置 SecurityContext，即可实现基于 Token 的鉴权。配置文件需指定密钥和过期时间。

# application.properties
jwt.secret=mysecret
jwt.expiration=3600

总结

通过上述内容，我们完成了 Spring Boot RESTful API 从设计到落地的全过程。重点掌握了资源导向的设计理念、分层开发的代码结构、三种不同粒度的测试方法，以及基于 Spring Security 的安全防护方案。在实际项目中，根据业务复杂度灵活组合这些技术点，才能构建出既高效又安全的后端服务。