用springboot,在表cart(cartid,cid,uid,cnum,cprice,cartselected),orders(oid,uid,cid,ocondition,oprice,ocount)的基础上实现购物车功能，代码包括html,entity,service,controller

好的，下面是代码实现：

1. 实体类 Cart

@Entity
@Table(name = "cart")
public class Cart {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer cartid;
    private Integer cid;
    private Integer uid;
    private Integer cnum;
    private Double cprice;
    private Boolean cartselected;

    // 省略getter和setter
}

2. 实体类 Orders

@Entity
@Table(name = "orders")
public class Orders {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer oid;
    private Integer uid;
    private Integer cid;
    private String ocondition;
    private Double oprice;
    private Integer ocount;

    // 省略getter和setter
}

3. CartService接口

public interface CartService {
    List<Cart> listByUid(Integer uid);
    void add(Integer uid, Integer cid, Integer cnum, Double cprice);
    void update(Integer cartid, Integer cnum, Double cprice, Boolean cartselected);
    void delete(Integer cartid);
}

4. CartServiceImpl实现类

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

    @Override
    public List<Cart> listByUid(Integer uid) {
        return cartRepository.findByUid(uid);
    }

    @Override
    public void add(Integer uid, Integer cid, Integer cnum, Double cprice) {
        Cart cart = cartRepository.findByUidAndCid(uid, cid);
        if (cart == null) {
            cart = new Cart();
            cart.setUid(uid);
            cart.setCid(cid);
            cart.setCnum(cnum);
            cart.setCprice(cprice);
            cart.setCartselected(true);
        } else {
            cart.setCnum(cart.getCnum() + cnum);
        }
        cartRepository.save(cart);
    }

    @Override
    public void update(Integer cartid, Integer cnum, Double cprice, Boolean cartselected) {
        Cart cart = cartRepository.findById(cartid).orElse(null);
        if (cart != null) {
            if (cnum != null) {
                cart.setCnum(cnum);
            }
            if (cprice != null) {
                cart.setCprice(cprice);
            }
            if (cartselected != null) {
                cart.setCartselected(cartselected);
            }
            cartRepository.save(cart);
        }
    }

    @Override
    public void delete(Integer cartid) {
        cartRepository.deleteById(cartid);
    }
}

5. CartController

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

    @GetMapping("/list")
    public List<Cart> listByUid(Integer uid) {
        return cartService.listByUid(uid);
    }

    @PostMapping("/add")
    public void add(Integer uid, Integer cid, Integer cnum, Double cprice) {
        cartService.add(uid, cid, cnum, cprice);
    }

    @PostMapping("/update")
    public void update(Integer cartid, Integer cnum, Double cprice, Boolean cartselected) {
        cartService.update(cartid, cnum, cprice, cartselected);
    }

    @PostMapping("/delete")
    public void delete(Integer cartid) {
        cartService.delete(cartid);
    }
}

6. 页面

购物车列表：

<div id="cartList"></div>
<script>
    $.get("/cart/list?uid=1", function (data) {
        var html = "";
        for (var i = 0; i < data.length; i++) {
            html += "<div>";
            html += "<input type='checkbox' name='cartselected' value='" + data[i].cartid + "' " + (data[i].cartselected ? "checked" : "") + ">";
            html += "<span>" + data[i].cid + "</span>";
            html += "<button onclick='deleteCart(" + data[i].cartid + ")'>删除</button>";
            html += "</div>";
        }
        $("#cartList").html(html);
    });
</script>

添加商品到购物车：

<form onsubmit="return false;">
    <input type="hidden" name="uid" value="1">
    <input type="number" name="cid" placeholder="商品ID" required>
    <input type="number" name="cnum" placeholder="数量" required>
    <input type="number" name="cprice" placeholder="价格" required>
    <button onclick="addCart()">添加到购物车</button>
</form>
<script>
    function addCart() {
        $.post("/cart/add", $("form").serialize(), function () {
            alert("添加成功");
        });
    }
</script>

更新购物车中商品的数量、价格和勾选状态：

<div>
    <input type="number" name="cnum" placeholder="数量" required>
    <input type="number" name="cprice" placeholder="价格" required>
    <input type="checkbox" name="cartselected" value="1" checked>勾选
    <button onclick="updateCart(1)">更新</button>
</div>
<script>
    function updateCart(cartid) {
        $.post("/cart/update", {cartid: cartid, cnum: $("input[name=cnum]").val(), cprice: $("input[name=cprice]").val(), cartselected: $("input[name=cartselected]").prop("checked")}, function () {
            alert("更新成功");
        });
    }
</script>

删除购物车中的商品：

<button onclick="deleteCart(1)">删除</button>
<script>
    function deleteCart(cartid) {
        $.post("/cart/delete", {cartid: cartid}, function () {
            alert("删除成功");
        });
    }
</script>