public interface CartMapper extends BaseMapper<Cart> { }

这是一个 Java 接口，名为 CartMapper，它继承了 BaseMapper<Cart> 接口。这个接口主要用于操作购物车（Cart）对象，可以进行增删改查等操作。BaseMapper 接口可能是一个通用的接口，提供了一些基本的数据库操作方法，比如查询所有、插入数据、更新数据等。继承了 BaseMapper<Cart> 接口之后，CartMapper 接口就可以直接使用这些基本方法。此外，这个接口的实现类需要通过 MyBatis 等框架来生成。

相关问题

@Modifying @Query(value = " update `user_shopping_cart` set valid=0,gmt_modified=now() WHERE valid=1 and activity_join_id in (?1)", nativeQuery = true) void removeByActivityJoinId(List<Long> activityJoinIdList);能不能动态控制where条件，某个字段有时需要有时不需要，灵活拼接

是的，您可以使用动态条件来拼接查询语句的 WHERE 子句。您可以使用 Spring Data JPA 提供的 Specification 对象来实现动态查询条件。

首先，您需要创建一个实现了 Specification 接口的类。在该类中，您可以根据需要拼接查询条件。以下是一个示例代码：

public class UserShoppingCartSpecification implements Specification<UserShoppingCart> {
    private List<Long> activityJoinIdList;
    private Boolean includeSomeField;

    public UserShoppingCartSpecification(List<Long> activityJoinIdList, Boolean includeSomeField) {
        this.activityJoinIdList = activityJoinIdList;
        this.includeSomeField = includeSomeField;
    }

    @Override
    public Predicate toPredicate(Root<UserShoppingCart> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
        List<Predicate> predicates = new ArrayList<>();

        // 添加 activityJoinIdList 条件
        predicates.add(root.get("activityJoinId").in(activityJoinIdList));

        // 添加 includeSomeField 条件
        if (includeSomeField) {
            predicates.add(criteriaBuilder.isNotNull(root.get("someField")));
        }

        // 组合所有条件
        return criteriaBuilder.and(predicates.toArray(new Predicate[0]));
    }
}

然后，您可以在您的 Repository 接口中使用这个 Specification 对象。以下是一个示例代码：

public interface UserShoppingCartRepository extends JpaRepository<UserShoppingCart, Long>, JpaSpecificationExecutor<UserShoppingCart> {

    @Modifying
    @Query(value = "UPDATE `user_shopping_cart` SET valid=0, gmt_modified=now() WHERE valid=1", nativeQuery = true)
    void removeByActivityJoinId(@Param("activityJoinIdList") List<Long> activityJoinIdList);

    default void removeByActivityJoinIdWithCondition(List<Long> activityJoinIdList, Boolean includeSomeField) {
        UserShoppingCartSpecification specification = new UserShoppingCartSpecification(activityJoinIdList, includeSomeField);
        removeByActivityJoinId(activityJoinIdList, specification);
    }
}

现在，您可以使用 `removeByActivityJoinIdWithCondition` 方法来动态拼接查询条件。根据传入的 `activityJoinIdList` 和 `includeSomeField` 参数，将会生成不同的 WHERE 子句。

请注意，这只是一个示例代码。您可以根据您的具体需求进行调整和扩展。希望能对您有所帮助！

帮我在user（uid，uname,upwd）,commodity(cid,cname,cprice),cart(cartid,uid,cid,cnum,cartprice，cartselected)三个表的基础上，用springboot 、maven完成购物车功能，包括entiity,controller,service,reposity，HTML等文件，告诉我代码

很抱歉，我之前的回答有误。以下是一个基于Spring Boot和Maven的购物车功能的代码示例：

1. entity/User.java

@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "uid")
    private Long uid;

    @Column(name = "uname")
    private String uname;

    @Column(name = "upwd")
    private String upwd;

    // getter and setter methods
}

2. entity/Commodity.java

@Entity
@Table(name = "commodity")
public class Commodity {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "cid")
    private Long cid;

    @Column(name = "cname")
    private String cname;

    @Column(name = "cprice")
    private Double cprice;

    // getter and setter methods
}

3. entity/Cart.java

@Entity
@Table(name = "cart")
public class Cart {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "cartid")
    private Long cartid;

    @ManyToOne
    @JoinColumn(name = "uid")
    private User user;

    @ManyToOne
    @JoinColumn(name = "cid")
    private Commodity commodity;

    @Column(name = "cnum")
    private Integer cnum;

    @Column(name = "cartprice")
    private Double cartprice;

    @Column(name = "cartselected")
    private Boolean cartselected;

    // getter and setter methods
}

4. repository/UserRepository.java

public interface UserRepository extends JpaRepository<User, Long> {
    // custom repository methods
}

5. repository/CommodityRepository.java

public interface CommodityRepository extends JpaRepository<Commodity, Long> {
    // custom repository methods
}

6. repository/CartRepository.java

public interface CartRepository extends JpaRepository<Cart, Long> {
    List<Cart> findByUser(User user);
}

7. service/UserService.java

public interface UserService {
    User addUser(User user);
    List<User> getAllUsers();
    User getUserById(Long uid);
    User updateUser(User user);
    void deleteUser(Long uid);
}

8. service/UserServiceImpl.java

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserRepository userRepository;

    @Override
    public User addUser(User user) {
        return userRepository.save(user);
    }

    @Override
    public List<User> getAllUsers() {
        return userRepository.findAll();
    }

    @Override
    public User getUserById(Long uid) {
        return userRepository.findById(uid).orElse(null);
    }

    @Override
    public User updateUser(User user) {
        return userRepository.save(user);
    }

    @Override
    public void deleteUser(Long uid) {
        userRepository.deleteById(uid);
    }
}

9. service/CommodityService.java

public interface CommodityService {
    Commodity addCommodity(Commodity commodity);
    List<Commodity> getAllCommodities();
    Commodity getCommodityById(Long cid);
    Commodity updateCommodity(Commodity commodity);
    void deleteCommodity(Long cid);
}

10. service/CommodityServiceImpl.java

@Service
public class CommodityServiceImpl implements CommodityService {
    @Autowired
    private CommodityRepository commodityRepository;

    @Override
    public Commodity addCommodity(Commodity commodity) {
        return commodityRepository.save(commodity);
    }

    @Override
    public List<Commodity> getAllCommodities() {
        return commodityRepository.findAll();
    }

    @Override
    public Commodity getCommodityById(Long cid) {
        return commodityRepository.findById(cid).orElse(null);
    }

    @Override
    public Commodity updateCommodity(Commodity commodity) {
        return commodityRepository.save(commodity);
    }

    @Override
    public void deleteCommodity(Long cid) {
        commodityRepository.deleteById(cid);
    }
}

11. service/CartService.java

public interface CartService {
    Cart addCartItem(Cart cartItem);
    List<Cart> getAllCartItems();
    Cart getCartItemById(Long cartid);
    Cart updateCartItem(Cart cartItem);
    void deleteCartItem(Long cartid);
    List<Cart> getCartItemsByUser(User user);
}

12. service/CartServiceImpl.java

@Service
public class CartServiceImpl implements CartService {
    @Autowired
    private CartRepository cartRepository;

    @Override
    public Cart addCartItem(Cart cartItem) {
        return cartRepository.save(cartItem);
    }

    @Override
    public List<Cart> getAllCartItems() {
        return cartRepository.findAll();
    }

    @Override
    public Cart getCartItemById(Long cartid) {
        return cartRepository.findById(cartid).orElse(null);
    }

    @Override
    public Cart updateCartItem(Cart cartItem) {
        return cartRepository.save(cartItem);
    }

    @Override
    public void deleteCartItem(Long cartid) {
        cartRepository.deleteById(cartid);
    }

    @Override
    public List<Cart> getCartItemsByUser(User user) {
        return cartRepository.findByUser(user);
    }
}

13. controller/CartController.java

@RestController
@RequestMapping("/cart")
public class CartController {
    @Autowired
    private CartService cartService;

    @PostMapping("/")
    public ResponseEntity<Cart> addCartItem(@RequestBody Cart cartItem) {
        Cart addedCartItem = cartService.addCartItem(cartItem);
        return new ResponseEntity<>(addedCartItem, HttpStatus.CREATED);
    }

    @GetMapping("/")
    public ResponseEntity<List<Cart>> getAllCartItems() {
        List<Cart> cartItems = cartService.getAllCartItems();
        return new ResponseEntity<>(cartItems, HttpStatus.OK);
    }

    @GetMapping("/{cartid}")
    public ResponseEntity<Cart> getCartItemById(@PathVariable Long cartid) {
        Cart cartItem = cartService.getCartItemById(cartid);
        HttpStatus status = cartItem != null ? HttpStatus.OK : HttpStatus.NOT_FOUND;
        return new ResponseEntity<>(cartItem, status);
    }

    @PutMapping("/")
    public ResponseEntity<Cart> updateCartItem(@RequestBody Cart cartItem) {
        Cart updatedCartItem = cartService.updateCartItem(cartItem);
        HttpStatus status = updatedCartItem != null ? HttpStatus.OK : HttpStatus.NOT_FOUND;
        return new ResponseEntity<>(updatedCartItem, status);
    }

    @DeleteMapping("/{cartid}")
    public ResponseEntity<Void> deleteCartItem(@PathVariable Long cartid) {
        cartService.deleteCartItem(cartid);
        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
    }

    @GetMapping("/user/{uid}")
    public ResponseEntity<List<Cart>> getCartItemsByUser(@PathVariable Long uid) {
        User user = new User();
        user.setUid(uid);
        List<Cart> cartItems = cartService.getCartItemsByUser(user);
        return new ResponseEntity<>(cartItems, HttpStatus.OK);
    }
}

14. HTML文件

购物车页面HTML文件示例：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>购物车</title>
</head>
<body>
    <h1>购物车</h1>
    <table>
        <thead>
            <tr>
                <th>商品名称</th>
                <th>单价</th>
                <th>数量</th>
                <th>小计</th>
                <th>是否选中</th>
            </tr>
        </thead>
        <tbody>
            <tr th:each="cartItem : ${cartItems}">
                <td th:text="${cartItem.commodity.cname}"></td>
                <td th:text="${cartItem.commodity.cprice}"></td>
                <td>
                    <input type="number" th:value="${cartItem.cnum}" onchange="changeCartItemNum(this, [[${cartItem.cartid}]])"/>
                </td>
                <td th:text="${cartItem.cartprice}"></td>
                <td>
                    <input type="checkbox" th:checked="${cartItem.cartselected}" onchange="changeCartItemSelection(this, [[${cartItem.cartid}]])"/>
                </td>
            </tr>
        </tbody>
    </table>
    <div>
        <button onclick="selectAllCartItems()">全选</button>
        <button onclick="deselectAllCartItems()">全不选</button>
        <button onclick="calculateTotalPrice()">计算总价</button>
    </div>
    <script>
        function changeCartItemNum(input, cartItemId) {
            var num = input.value;
            var data = {
                cartid: cartItemId,
                cnum: num,
            };
            $.ajax({
                url: "/cart/",
                type: "PUT",
                data: data,
                success: function() {
                    location.reload();
                },
                error: function() {
                    alert("修改购物车商品数量失败！");
                },
            });
        }

        function changeCartItemSelection(input, cartItemId) {
            var selected = input.checked;
            var data = {
                cartid: cartItemId,
                cartselected: selected,
            };
            $.ajax({
                url: "/cart/",
                type: "PUT",
                data: data,
                success: function() {
                    location.reload();
                },
                error: function() {
                    alert("修改购物车商品选中状态失败！");
                },
            });
        }

        function selectAllCartItems() {
            var cartItemIds = [];
            $("input[type='checkbox']").each(function() {
                cartItemIds.push($(this).attr("data-cart-item-id"));
            });
            var data = {
                cartids: cartItemIds,
                cartselected: true,
            };
            $.ajax({
                url: "/cart/",
                type: "PUT",
                data: data,
                success: function() {
                    location.reload();
                },
                error: function() {
                    alert("全选购物车商品失败！");
                },
            });
        }

        function deselectAllCartItems() {
            var cartItemIds = [];
            $("input[type='checkbox']").each(function() {
                cartItemIds.push($(this).attr("data-cart-item-id"));
            });
            var data = {
                cartids: cartItemIds,
                cartselected: false,
            };
            $.ajax({
                url: "/cart/",
                type: "PUT",
                data: data,
                success: function() {
                    location.reload();
                },
                error: function() {
                    alert("全不选购物车商品失败！");
                },
            });
        }

        function calculateTotalPrice() {
            var totalPrice = 0;
            $("input[type='checkbox']").each(function() {
                if ($(this).is(":checked")) {
                    var price = parseFloat($(this).closest("tr").find("td:eq(3)").text());
                    totalPrice += price;
                }
            });
            alert("总价为：" + totalPrice.toFixed(2));
        }
    </script>
</body>
</html>

以上代码仅供参考，具体实现还需要根据您的具体需求进行调整和完善。