Spring Boot RESTful API 开发实战与测试指南

2. 实体类定义

实体类映射数据库表，这里以商品（Product）为例。注意字段类型和 Getter/Setter 方法的完整性。

import javax.persistence.*;
import java.util.Objects;

@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, ensure they are present
    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. Repository 接口

继承 JpaRepository 即可自动获得基础的 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. Service 层逻辑

Service 层处理业务逻辑，如事务控制。这里展示了添加、更新、删除及获取热销商品的逻辑。

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. Controller 层接口

Controller 负责接收 HTTP 请求并返回响应。使用 @RestController 配合 ResponseEntity 可以更灵活地控制状态码。

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

测试是保证代码质量的关键。我们通常从单元测试开始，逐步扩展到集成测试和 Mock 测试。

单元测试

单元测试主要关注单个 Service 方法的功能，不依赖外部容器或网络。

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);
        // 验证排序逻辑
        assertThat(topSellingProducts.get(0).getProductId()).isEqualTo("P004");
    }
}

集成测试

集成测试需要启动完整的 Web 环境，模拟真实的 HTTP 请求。使用 TestRestTemplate 是最便捷的方式。

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);
    }
}

Mock 测试

当我们需要隔离 Controller 与 Service 之间的依赖时，可以使用 WebMvcTest 结合 MockBean。这能显著加快测试速度。

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)
        );
        when(productService.getAllProducts()).thenReturn(products);
        mockMvc.perform(get("/api/products/"))
               .andExpect(status().isOk())
               .andExpect(content().contentType(MediaType.APPLICATION_JSON));
        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));
    }
}

Spring Boot RESTful API 的认证与授权

生产环境的 API 必须考虑安全性。Spring Boot 提供了强大的安全框架支持。

Spring Security 基础认证

对于简单的内部系统，HTTP Basic Auth 可能足够。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.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

对于前后端分离的应用，JWT（JSON Web Token）是更常见的选择。它允许服务端在无会话状态下验证用户身份。

依赖配置：

<!-- JWT 依赖 -->
<dependency>
    <groupId>io.jsonwebtoken</groupId>
    <artifactId>jjwt</artifactId>
    <version>0.9.1</version>
</dependency>

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));
    }
}

过滤器：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.web.authentication.WebAuthenticationDetailsSource;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class JwtRequestFilter extends OncePerRequestFilter {
    @Autowired
    private UserDetailsService userDetailsService;

    @Autowired
    private JwtUtil jwtUtil;

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws ServletException, IOException {
        final String authorizationHeader = request.getHeader("Authorization");
        String username = null;
        String jwt = null;

        if (authorizationHeader != null && authorizationHeader.startsWith("Bearer ")) {
            jwt = authorizationHeader.substring(7);
            username = jwtUtil.extractUsername(jwt);
        }

        if (username != null && SecurityContextHolder.getContext().getAuthentication() == null) {
            UserDetails userDetails = this.userDetailsService.loadUserByUsername(username);
            if (jwtUtil.validateToken(jwt, userDetails.getUsername())) {
                UsernamePasswordAuthenticationToken usernamePasswordAuthenticationToken =
                        new UsernamePasswordAuthenticationToken(userDetails, null, userDetails.getAuthorities());
                usernamePasswordAuthenticationToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));
                SecurityContextHolder.getContext().setAuthentication(usernamePasswordAuthenticationToken);
            }
        }
        chain.doFilter(request, response);
    }
}

配置文件：

# application.properties
server.port=8080
spring.datasource.url=jdbc:h2:mem:testdb
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
jwt.secret=mysecret
jwt.expiration=3600

实际应用场景总结

在实际项目中，RESTful API 广泛应用于商品展示、订单管理、用户中心及内容发布等场景。通过上述的分层架构、测试策略及安全配置，我们可以构建出高可用、易维护的后端服务。开发者应根据具体需求选择合适的认证方式（如 Session 或 JWT），并确保测试覆盖率达到预期标准。

从下一章开始，我们将进一步探索 Spring Boot 的其他组件及微服务架构的相关内容。