Sky delivery system 07

hello! Hello everyone, I am Mr. Li, a masterful wizard.
The article is continuously updated. You can search [Xiaoqi JAVA Interview] on WeChat to read it immediately. Reply to [Information] and I have prepared benefits for you. Reply to [Project] to get what I have prepared for you. s project

Recently, I plan to share with you the project I have done before. This Kungqiong delivery system is made following a video on station B. You can learn by yourself from the video, or you can directly use the
project I have done.

Related Reading

• Interviewer: What is Zookeeper, what are its features and usage scenarios?
• Interviewer: How does Redis achieve persistence, and what is the master-slave sentinel?

1. The front-end page of the background management system

1. Login password encryption

Use spring's own encryption tool class for md5 encryption

password = DigestUtils.md5DigestAsHex(password.getBytes());

2. Swagger introduction

First introduce the dependency

<dependency>
            <groupId>com.github.xiaoymin</groupId>
            <artifactId>knife4j-spring-boot-starter</artifactId>
            <version>3.0.2</version>
</dependency>

Then configure the basic information and the location of the controller package to be scanned

package com.sky.config;

import com.sky.interceptor.JwtTokenAdminInterceptor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;

/**
 * 配置类，注册web层相关组件
 */
@Configuration
@Slf4j
public class WebMvcConfiguration extends WebMvcConfigurationSupport {

    @Autowired
    private JwtTokenAdminInterceptor jwtTokenAdminInterceptor;

    /**
     * 注册自定义拦截器
     *
     * @param registry
     */
    protected void addInterceptors(InterceptorRegistry registry) {
        log.info("开始注册自定义拦截器...");
        registry.addInterceptor(jwtTokenAdminInterceptor)
                .addPathPatterns("/admin/**")
                .excludePathPatterns("/admin/employee/login");
    }

    /**
     * 通过knife4j生成接口文档
     * @return
     */
    @Bean
    public Docket docket() {
        log.info("准备生成接口文档...");
        ApiInfo apiInfo = new ApiInfoBuilder()
                .title("苍穹外卖项目接口文档")
                .version("2.0")
                .description("苍穹外卖项目接口文档")
                .build();
        Docket docket = new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo)
                .select()
                .apis(RequestHandlerSelectors.basePackage("com.sky.controller"))
                .paths(PathSelectors.any())
                .build();
        return docket;
    }

    /**
     * 设置静态资源映射
     * @param registry
     */
    protected void addResourceHandlers(ResourceHandlerRegistry registry) {
        log.info("开始设置静态资源映射...");
        registry.addResourceHandler("/doc.html").addResourceLocations("classpath:/META-INF/resources/");
        registry.addResourceHandler("/webjars/**").addResourceLocations("classpath:/META-INF/resources/webjars/");
    }
}

then visit the page

http://localhost:8080/doc.html

3. Swagger common annotations

4. Object attribute copy

//对象属性拷贝，DTO的属性名和实体类的属性名相同
        BeanUtils.copyProperties(employeeDTO,employee);

5. SQL exception handling (add exception capture for employees with the same username)

 /**
     * @Description: 处理SQL异常
     * @Author: KSQC
     */
    @ExceptionHandler
    public Result exceptionHandler(SQLIntegrityConstraintViolationException ex){
        //Duplicate entry 'zhangsan' for key 'idx_username'
        String message = ex.getMessage();
        if(message.contains("Duplicate entry")){
            String[] split = message.split(" ");
            String username = split[2];
            String msg = username + "已存在";
            return Result.error(msg);
        }else {
            return Result.error("未知错误");
        }
    }

6. ThreadLocal is used to store user information, and is used to assign the attribute of the adder when adding a new user

First create a tool class

public class BaseContext {

    public static ThreadLocal<Long> threadLocal = new ThreadLocal<>();

    public static void setCurrentId(Long id) {
        threadLocal.set(id);
    }

    public static Long getCurrentId() {
        return threadLocal.get();
    }

    public static void removeCurrentId() {
        threadLocal.remove();
    }

}

Put user information into ThreadLocal when logging in

//将用户id放入线程中去
            BaseContext.setCurrentId(empId);

When adding a new user, assign the added person information

        //设置当前记录创建人id和修改人id
        employee.setCreateUser(BaseContext.getCurrentId());
        employee.setUpdateUser(BaseContext.getCurrentId());

7. Query employees by page

First introduce the dependency pagehelper, which is a paging plugin provided by mybatis

            <dependency>
                <groupId>com.github.pagehelper</groupId>
                <artifactId>pagehelper-spring-boot-starter</artifactId>
                <version>${pagehelper}</version>
            </dependency>

Then perform pagination query code development

 /**
     * @Description: 分页查询
     * @Author: KSQC
     */
    public PageResult pageQuery(EmployeePageQueryDTO employeePageQueryDTO) {
        //开始分页查询,传入参数为第几页和每页展示多少行。
        PageHelper.startPage(employeePageQueryDTO.getPage(),employeePageQueryDTO.getPageSize());

        //普通正常查询，因为PageHelper会将分页信息存入当前线程，会在正常查询时进行拼接。
        Page<Employee> page = employeeMapper.pageQuery(employeePageQueryDTO);

        //将PageResult需要的属性获取出来进行返回。
        long total = page.getTotal();
        List<Employee> records = page.getResult();

        return new PageResult(total,records);
    }

8. Date formatting processing

The first method: annotate directly on the attribute

    //@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime createTime;

The second method: configure the global message converter

  /**
     * @Description: 扩展SpringMVC框架的消息转化器
     * @Author: KSQC
     */
    protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        log.info("扩展消息转换器...");
        //创建一个消息转换器对象
        MappingJackson2HttpMessageConverter converter = new MappingJackson2HttpMessageConverter();
        //需要为消息转换器设置一个对象转换器，对象转换器可以将Java对象序列化json数据
        converter.setObjectMapper(new JacksonObjectMapper());
        //将自己的消息转化器加入容器中
        converters.add(0,converter);
    }

The converter entity class is as follows:

package com.sky.json;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

import static com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES;

/**
 * 对象映射器:基于jackson将Java对象转为json，或者将json转为Java对象
 * 将JSON解析为Java对象的过程称为 [从JSON反序列化Java对象]
 * 从Java对象生成JSON的过程称为 [序列化Java对象到JSON]
 */
public class JacksonObjectMapper extends ObjectMapper {

    public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
    //public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
    public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm";
    public static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";

    public JacksonObjectMapper() {
        super();
        //收到未知属性时不报异常
        this.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);

        //反序列化时，属性不存在的兼容处理
        this.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

        SimpleModule simpleModule = new SimpleModule()
                .addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                .addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                .addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)))
                .addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                .addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                .addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));

        //注册功能模块 例如，可以添加自定义序列化器和反序列化器
        this.registerModule(simpleModule);
    }
}

9. Common field code filling (filling public fields through AOP and reflection)

package com.sky.aspect;/**
 * @Author: KSQC
 * @Description: ${description}
 * @Date: 2023/8/8 21:08
 */

import com.sky.annotation.AutoFill;
import com.sky.constant.AutoFillConstant;
import com.sky.context.BaseContext;
import com.sky.enumeration.OperationType;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.stereotype.Component;

import java.lang.reflect.Method;
import java.time.LocalDateTime;

/**
 * @Description 自定义切面，实现公共字段自动填充处理逻辑
 * @Author LiShiQi
 * @Date 2023/8/8 21:08
 * @Version 1.0
 */
@Aspect
@Component
@Slf4j
public class AutoFillAspect {

    /**
     *  切入点
     */
    @Pointcut("execution(* com.sky.mapper.*.*(..)) && @annotation(com.sky.annotation.AutoFill)")
    public void autoFillPointCut(){}

    /**
     *  前置通知，在通知中进行公共字段的赋值
     */
    @Before("autoFillPointCut()")
    public void autoFill(JoinPoint joinPoint){
        log.info("开始进行公共字段自动填充...");

        //获取到当前被拦截的方法上的数据库操作类型
        MethodSignature signature = (MethodSignature) joinPoint.getSignature();//方法签名对象
        AutoFill autoFill = signature.getMethod().getAnnotation(AutoFill.class);//获得方法上的注解对象
        OperationType operationType = autoFill.value();

        //获取到当前被拦截的方法的参数--实体对象
        Object[] args = joinPoint.getArgs();
        if(args == null || args.length == 0){
            return;
        }

        Object entity = args[0];

        //准备赋值的数据
        LocalDateTime now = LocalDateTime.now();
        Long currentId = BaseContext.getCurrentId();


        //根据当前不同的操作类型，为对应的属性通过反射来赋值
        if(operationType == OperationType.INSERT){
            //为4个公共字段赋值
            try {
                Method setCreateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_TIME, LocalDateTime.class);
                Method setCreateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_CREATE_USER, Long.class);
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
                Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);

                //通过反射为对象属性赋值
                setCreateTime.invoke(entity,now);
                setCreateUser.invoke(entity,currentId);
                setUpdateTime.invoke(entity,now);
                setUpdateUser.invoke(entity,currentId);
            } catch (Exception e) {
                e.printStackTrace();
            }

        }else if(operationType == OperationType.UPDATE){
            //为2个公共字段赋值

            try {
                Method setUpdateTime = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_TIME, LocalDateTime.class);
                Method setUpdateUser = entity.getClass().getDeclaredMethod(AutoFillConstant.SET_UPDATE_USER, Long.class);

                //通过反射为对象属性赋值
                setUpdateTime.invoke(entity,now);
                setUpdateUser.invoke(entity,currentId);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }

}

10. Use Alibaba Cloud to store pictures

Configure Alibaba Cloud address and other related parameters

  alioss:
    endpoint: oss-cn-beijing.aliyuncs.com
    access-key-id: LTAI5tPeFLzsPPT8gG3LPW64
    access-key-secret: U6k1brOZ8gaOIXv3nXbulGTUzy6Pd7
    bucket-name: sky-itcast

Create a new Alibaba Cloud configuration class

package com.sky.config;

import com.sky.properties.AliOssProperties;
import com.sky.utils.AliOssUtil;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @Author: KSQC
 * @Description: 配置类，用于创建AliOssUtil对象
 * @Date: 2023/8/9 9:40
 */
@Configuration
@Slf4j
public class OssConfiguration {

    @Bean
    @ConditionalOnMissingBean
    public AliOssUtil aliOssUtil(AliOssProperties aliOssProperties){
        log.info("开始创建阿里云文件上传工具类对象：{}",aliOssProperties);
        return new AliOssUtil(aliOssProperties.getEndpoint(),
                aliOssProperties.getAccessKeyId(),
                aliOssProperties.getAccessKeySecret(),
                aliOssProperties.getBucketName());

    }
}

Call the tool class to upload pictures to Alibaba Cloud, and return the picture address for front-end display

//文件的请求路径
            String filePath = aliOssUtil.upload(file.getBytes(),objectName);

11. Use redis to do store status function

Configure redis under spring

 # redis 配置
  redis:
    # 地址
    host: localhost
    # 端口，默认为6379
    port: 6379
    # 数据库索引
    database: 0
    # 密码
    password: 123456
    # 连接超时时间
    timeout: 10s
    lettuce:
      pool:
        # 连接池中的最小空闲连接
        min-idle: 0
        # 连接池中的最大空闲连接
        max-idle: 8
        # 连接池的最大数据库连接数
        max-active: 8
        # #连接池最大阻塞等待时间（使用负值表示没有限制）
        max-wait: -1ms

Create a RedisConfiguration class

package com.sky.config;/**
 * @Author: KSQC
 * @Description: ${description}
 * @Date: 2023/8/9 15:21
 */

import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.StringRedisSerializer;

/**
 * @Description
 * @Author LiShiQi
 * @Date 2023/8/9 15:21
 * @Version 1.0
 */
@Configuration
@Slf4j
public class RedisConfiguration {

    @Bean
    public RedisTemplate redisTemplate(RedisConnectionFactory redisConnectionFactory){
        log.info("开始创建redis模板对象...");
        RedisTemplate redisTemplate = new RedisTemplate();
        //设置redis的连接工厂对象
        redisTemplate.setConnectionFactory(redisConnectionFactory);
        //设置redis key的序列化器
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        return redisTemplate;
    }
}

Set store status

 /**
     * @Description: 设置店铺的营业状态
     * @Author: KSQC
     */
    @PutMapping("/{status}")
    @ApiOperation("设置店铺的营业状态")
    public Result setStatus(@PathVariable Integer status){
        log.info("设置店铺的营业状态为：{}",status == 1 ? "营业中" : "打烊中");
        redisTemplate.opsForValue().set(KEY,status);

        return Result.success();
    }

12. Use Sping-Cache to cache package data

First, introduce dependencies. In addition to introducing spring-cache dependencies, you also need to introduce redis dependencies, because the bottom layer of spring-cache needs to use a cache middleware, which can support a variety of middleware. Currently, we use redis as cache middleware.

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>

Commonly used annotations, when we introduce dependencies, we can use annotations to perform cache operations.

First start the class to enable the annotation function

Then find the query method we need to cache and add annotations. Here we will use "setmealCache" as a prefix, and then add our category id as a key, and then use the queried data as a value and put it in redis. When we second At the time of the second query, there is data in redis at this time, and the data in our redis will be returned directly without querying the database, which greatly reduces the pressure on our database.

Clear the cache when adding a new package, because the newly added package will be displayed on the page, but the cache contains old data, so we need to clear the cache, and then re-query the database and re-cache. Here we clean up according to the category id, and under which category a new package is added, the category cache will be cleared.

When deleting packages in batches, we perform batch cleanup, and clean up all the packages with the prefix "setmealCache".

12. Use Sping-Task to execute timed tasks

The dependencies of this task are included in the context package, so we don't need to introduce additional dependencies.

We need to add the annotation "@EnableScheduling" to the startup class first

Then add annotations to the methods that need to be executed regularly, and write the execution time. The cron syntax is used here. If you don’t know it, you can query it on Baidu.

13. Use WebSocket to realize order reminder and order reminder

First introduce the dependency

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

Create a new WebSocketConfiguration configuration class

package com.sky.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * WebSocket配置类，用于注册WebSocket的Bean
 */
@Configuration
public class WebSocketConfiguration {

    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

}

Then create a WebSocketServer functional class

package com.sky.websocket;

import org.springframework.stereotype.Component;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

/**
 * WebSocket服务
 */
@Component
@ServerEndpoint("/ws/{sid}")
public class WebSocketServer {

    //存放会话对象
    private static Map<String, Session> sessionMap = new HashMap();

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("sid") String sid) {
        System.out.println("客户端：" + sid + "建立连接");
        sessionMap.put(sid, session);
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, @PathParam("sid") String sid) {
        System.out.println("收到来自客户端：" + sid + "的信息:" + message);
    }

    /**
     * 连接关闭调用的方法
     *
     * @param sid
     */
    @OnClose
    public void onClose(@PathParam("sid") String sid) {
        System.out.println("连接断开:" + sid);
        sessionMap.remove(sid);
    }

    /**
     * 群发
     *
     * @param message
     */
    public void sendToAllClient(String message) {
        Collection<Session> sessions = sessionMap.values();
        for (Session session : sessions) {
            try {
                //服务器向客户端发送消息
                session.getBasicRemote().sendText(message);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

}

Then we call the method in the specific business code to send a message to the front end, such as sending a message after the order is successfully placed.

        //通过websocket向客户端浏览器推送消息 type orderId content
        Map map = new HashMap();
        map.put("type",1); // 1表示来单提醒 2表示客户催单
        map.put("orderId",ordersDB.getId());
        map.put("content","订单号：" + outTradeNo);

        String json = JSON.toJSONString(map);
        webSocketServer.sendToAllClient(json);

The following is the front-end code of the test case. After the front-end needs to be started, it needs to establish a WebSocket connection with the back-end, so that subsequent communication can be carried out.

<!DOCTYPE HTML>
<html>
<head>
    <meta charset="UTF-8">
    <title>WebSocket Demo</title>
</head>
<body>
    <input id="text" type="text" />
    <button onclick="send()">发送消息</button>
    <button onclick="closeWebSocket()">关闭连接</button>
    <div id="message">
    </div>
</body>
<script type="text/javascript">
    var websocket = null;
    var clientId = Math.random().toString(36).substr(2);

    //判断当前浏览器是否支持WebSocket
    if('WebSocket' in window){
        //连接WebSocket节点
        websocket = new WebSocket("ws://localhost:8080/ws/"+clientId);
    }
    else{
        alert('Not support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function(){
        setMessageInnerHTML("error");
    };

    //连接成功建立的回调方法
    websocket.onopen = function(){
        setMessageInnerHTML("连接成功");
    }

    //接收到消息的回调方法
    websocket.onmessage = function(event){
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function(){
        setMessageInnerHTML("close");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function(){
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML){
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //发送消息
    function send(){
        var message = document.getElementById('text').value;
        websocket.send(message);
    }
	
	//关闭连接
    function closeWebSocket() {
        websocket.close();
    }
</script>
</html>

2. Display of the WeChat Mini Program client page

pending authorization page

Confirm authorization page

front page

Choose Flavor Page

shopping cart page

submit order page

Click on the avatar page

History Order Page

Address management page

3. Merchant backend page display

Workbench display page

Statistics page

Order management page

Dishes management page

Category management page

Employee Management Page

Store status modification page

Four. Summary

The functions involved in the project are relatively comprehensive. It is recommended that you follow the video to do it again. You can follow the official account and reply to [Project] to receive the project. If it is useful, please like and support it.

The article is continuously updated, you can search [ Xiaoqi JAVA Interview ] on WeChat to read it immediately, and reply to [ Project ] to get the project I prepared for you