java框架中使用测试驱动开发（TDD）方法进行单元测试和集成测试

import org.junit.Test;

public class MathUtilTest {

    @Test
    public void testAdd() {
        MathUtil mathUtil = new MathUtil();
        int result = mathUtil.add(1, 2);
        assertEquals(3, result);
    }
}

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import static org.mockito.Mockito.when;

@RunWith(SpringRunner.class)
@SpringBootTest
public class OrderServiceTest {

    @Autowired
    private OrderService orderService;

    @Test
    public void testPlaceOrder() {
        // 模拟商品库返回商品信息
        ProductService productServiceMock = Mockito.mock(ProductService.class);
        when(productServiceMock.getProductById(1)).thenReturn(new Product("Product 1", 100));

        // 模拟用户服务返回用户信息
        UserService userServiceMock = Mockito.mock(UserService.class);
        when(userServiceMock.getUserById(1)).thenReturn(new User("User 1"));

        // 使用模拟服务调用 orderService
        Order order = orderService.placeOrder(1, 1);

        // 断言订单正确创建
        assertEquals("Product 1", order.getProduct().getName());
        assertEquals(100, order.getProduct().getPrice());
        assertEquals("User 1", order. getUser().getName());
    }
}