- Shopping cart delete operation
===========
1.1 Page analysis
1.2 edit CartController
`/**
* Shopping cart delete operation
* url Address : http://www.jt.com/cart/delete/562379.html
* Parameters : obtain itemId
* Return value : Redirect to the presentation page of the shopping cart
*/
@RequestMapping("/delete/{itemId}")
public String deleteCarts(@PathVariable Long itemId){
Long userId = 7L;
cartService.deleteCarts(userId,itemId);
return "redirect:/cart/show.html";
}`
1.3 edit CartService
`@Override
public void deleteCarts(Long userId, Long itemId) {
QueryWrapper<Cart> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("user_id", userId);
queryWrapper.eq("item_id", itemId);
cartMapper.delete(queryWrapper);
}`
- Jingtao permissions to achieve
==========
2.1 Business needs
When a user makes sensitive operations , Users must be required to log in before they can access the back-end server . For example, Jingdong Mall …
Using technology :
1.AOP
2. Interceptor : Block user requests 
2.2 Define Jingtao interceptor
2.2.1 SpringMVC Call schematic 
2.2.2 SpringMVC How interceptors work
2.2.3 Configure interceptors
`@Component //spring Container management object
public class UserInterceptor implements HandlerInterceptor {
@Autowired
private JedisCluster jedisCluster;
//Spring Version update 4 All methods have to be implemented spring 5 Just override the specified method .
/**
* demand : Intercept /cart All requests at the beginning are intercepted ., And verify that the user is logged in .....
* Interceptor selection : preHandler
* How to determine whether a user is logged in : 1. Check cookie Information 2. Check Redis Is there a record in .
* true : The request should be released
* false: Requests should be blocked Then with the syntax of redirection, the page will jump to the login page Make the program flow
*/
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
//1. Determine whether the user is logged in Check cookie If there is a value
String ticket = CookieUtil.getCookieValue(request,"JT_TICKET");
//2. check ticket
if(!StringUtils.isEmpty(ticket)){
//3. Judge redis Is there any value in .
if(jedisCluster.exists(ticket)){
//4. Get dynamic json Information
String userJSON = jedisCluster.get(ticket);
User user = ObjectMapperUtil.toObj(userJSON,User.class);
request.setAttribute("JT_USER",user);
return true;
}
}
response.sendRedirect("/user/login.html");
return false;
}
@Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
// Destroy data
request.removeAttribute("JT_USER");
}
}`
2.2.4 Get dynamic UserId
2.3 ThreadLocal Introduce
2.3.1 ThreadLocal effect
name : Local thread variables
effect : Can be in the same thread , Realize the sharing of data .
2.3.2 ThreadLocal Introductory cases
`private ThreadLocal<Integer> threadLocal = new ThreadLocal<>();
public void a(){
int a = 100;
threadLocal.set(a);
b();
}
public void b(){
int a = threadLocal.get();
int b = 100*a;
}`
2.3.3 edit ThreadLocal Tools API
`public class UserThreadLocal {
//static It doesn't affect threads threadLocal When a thread is created, it follows .
//private static ThreadLocal<Map<k,v>> threadLocal = new ThreadLocal<>();
private static ThreadLocal<User> threadLocal = new ThreadLocal<>();
public static void set(User user){
threadLocal.set(user);
}
public static User get(){
return threadLocal.get();
}
public static void remove(){
threadLocal.remove();
}
}`
2.3.4 restructure User Interceptor
2.3.5 Get dynamic UserId
3. Jingtao order module
3.1 Order form design
3.2 Create order items
3.2.1 Create project
3.2.2 Add inheritance dependency
`<!--2. Add dependency information -->
<dependencies>
<!-- What depends essentially on is jar Package file -->
<dependency>
<groupId>com.jt</groupId>
<artifactId>jt-common</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
</dependencies>
<!--3. Add the plug-in -->
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>`
3.2.3 add to POJO
Delete orderItem The primary key ID of 
3.2.4 structure jt-order project
The order item code structure is as follows 
3.3 Order confirmation page jumps to
3.3.1 url analysis
3.3.2 edit OrderController
`package com.jt.controller;
import com.alibaba.dubbo.config.annotation.Reference;
import com.jt.pojo.Cart;
import com.jt.service.DubboCartService;
import com.jt.service.DubboOrderService;
import com.jt.thread.UserThreadLocal;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.List;
@Controller
@RequestMapping("/order")
public class OrderController {
@Reference(timeout = 3000,check = false)
private DubboOrderService orderService;
@Reference(timeout = 3000,check = false)
private DubboCartService cartService;
/**
* Order page Jump
* url: http://www.jt.com/order/create.html
* Page value : ${carts}
*/
@RequestMapping("/create")
public String create(Model model){
//1. according to userId Query shopping cart information
Long userId = UserThreadLocal.get().getId();
List<Cart> cartList = cartService.findCartListByUserId(userId);
model.addAttribute("carts",cartList);
return "order-cart";
}
}`
3.3.3 edit OrderService
`@Override
public List<Cart> findCartListByUserId(Long userId) {
QueryWrapper<Cart> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("user_id", userId);
return cartMapper.selectList(queryWrapper);
}`
3.3.4 Page effect display
3.4 About SpringMVC Parameter submission problem description
3.4.1 Simple parameter transfer problem
1. page url identification
2.Controller The method in
public void xxx(String name,int age){
`}`
3.4.2 Use object methods to receive parameters
1. page url identification
2.Controller The method in
public void xxx(User user){
`}
public class User{
private Integer name;
private String age;
}`
3.4.3 Use the object's reference to assign values to parameters
difficulty : Attribute's duplicate name submission problem …
Solutions : You can assign values to properties in the form of object references .
`<input name="name" value=" Erlang God " />
<input name="age" value="3000" />
<input name="dog.name" value=" Wheezing dog " />
<input name="dog.age" value="8000" />`
2.Controller The method in
`public void xxx(User user){
}
public class Dog{
private String name;
private Integer age;
}
public class User{
private String name;
private Integer age;
private Dog dog;
}`
3.5 About order submission
3.5.1 page URL explain
3.5.2 Request parameters
3.5.3 page JS analysis
`jQuery.ajax( {
type : "POST",
dataType : "json",
url : "/order/submit",
data : $("#orderForm").serialize(),
// data: {"key":"value","key2":"value2".....}
// data: id=1&name="xxx"&age=18......
cache : false,
success : function(result) {
if(result.status == 200){
location.href = "/order/success.html?id="+result.data;
}else{
$("#submit_message").html(" Order submission failed , Please try again later ...").show();
}
},
error : function(error) {
$("#submit_message").html(" Dear users, please do not click frequently , Please try again later ...").show();
}
});`
3.5.3 edit OrderController
`/**
* Order submission
* url: http://www.jt.com/order/submit
* Parameters : Whole form Forms
* Return value : SysResult object Carry return value orderId
* Business description :
* When the order is put into storage , Need to return orderId. Let the user query .
*/
@RequestMapping("/submit")
@ResponseBody
public SysResult saveOrder(Order order){
Long userId = UserThreadLocal.get().getId();
order.setUserId(userId);
String orderId = orderService.saveOrder(order);
if(StringUtils.isEmpty(orderId))
return SysResult.fail();
else
return SysResult.success(orderId);
}`
3.5.4 edit OrderService
`@Service(timeout = 3000)
public class DubboOrderServiceImpl implements DubboOrderService {
@Autowired
private OrderMapper orderMapper;
@Autowired
private OrderItemMapper orderItemMapper;
@Autowired
private OrderShippingMapper orderShippingMapper;
/**
* Order{order The order itself /order Logistics information /order Commodity information }
* difficulty : operation 3 Tables complete the warehousing operation
* Primary key information : orderId
* @param order
* @return
*/
@Override
public String saveOrder(Order order) {
//1. Splicing OrderId
String orderId =
"" + order.getUserId() + System.currentTimeMillis();
//2. Complete the order warehousing
order.setOrderId(orderId).setStatus(1);
orderMapper.insert(order);
//3. Complete the order logistics warehousing
OrderShipping orderShipping = order.getOrderShipping();
orderShipping.setOrderId(orderId);
orderShippingMapper.insert(orderShipping);
//4. Complete the order goods warehousing
List<OrderItem> orderItems = order.getOrderItems();
// Bulk warehousing sql: insert into xxx(xxx,xx,xx)values (xx,xx,xx),(xx,xx,xx)....
for (OrderItem orderItem : orderItems){
orderItem.setOrderId(orderId);
orderItemMapper.insert(orderItem);
}
System.out.println(" The order has been put into storage successfully !!!!");
return orderId;
}
}`
3.6 Order successfully transferred
3.6.1 page url analysis
3.6.2 edit OrderController
`/**
* Realize commodity query
* 1.url Address : http://www.jt.com/order/success.html?id=71603356409924
* 2. Parameter description : id The order no.
* 3. return type : success.html
* 4. Page value method : ${order.orderId}
*/
@RequestMapping("/success")
public String findOrderById(String id,Model model){
Order order = orderService.findOrderById(id);
model.addAttribute("order",order);
return "success";
}`
3.6.2 edit OrderService
`@Override
public Order findOrderById(String id) {
//1. Query order information
Order order = orderMapper.selectById(id);
//2. Query order logistics information
OrderShipping orderShipping = orderShippingMapper.selectById(id);
//3. Query order line item
QueryWrapper<OrderItem> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("order_id",id);
List<OrderItem> lists =orderItemMapper.selectList(queryWrapper);
return order.setOrderItems(lists).setOrderShipping(orderShipping);
}`
3.6.3 Page effect display
4 Project structure chart
