十二条后端开发经验分享，纯干货，总有一条你不知道（后端开发百度百科）

　　本篇文章为你整理了十二条后端开发经验分享，纯干货，总有一条你不知道（后端开发百度百科）的详细内容，包含有后端开发后端开发百度百科后端开发主要做什么后端开发视频教程十二条后端开发经验分享，纯干货，总有一条你不知道，希望能帮助你了解十二条后端开发经验分享，纯干货，总有一条你不知道。

　　本文是博主从事后端开发以来，对公司、个人项目的经验总结，包含代码编写、功能推荐、第三方库使用及优雅配置等，希望大家看到都能有所收获

　　博主github地址: https://github.com/wayn111

　　一. 优雅的进行线程池异常处理

　　在Java开发中，线程池的使用必不可少，使用无返回值 execute() 方法时，线程执行发生异常的话，需要记录日志，方便回溯，一般做法是在线程执行方法内 try/catch 处理，如下：

@Test

　　public void test() throws Exception {

　　 ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(5, 10, 60,

　　 TimeUnit.SECONDS, new ArrayBlockingQueue (100000));

　　 Future Integer submit = threadPoolExecutor.execute(() - {

　　 try {

　　 int i = 1 / 0;

　　 return i;

　　 } catch (Exception e) {

　　 log.error(e.getMessage(), e);

　　 return null;

　　但是当线程池调用方法很多时，那么每个线程执行方法内都要 try/catch 处理，这就不优雅了，其实ThreadPoolExecutor类还支持传入 ThreadFactory 参数，自定义线程工厂，在创建 thread 时，指定 setUncaughtExceptionHandler 异常处理方法，这样就可以做到全局处理异常了，代码如下：

ThreadFactory threadFactory = r - {

　　 Thread thread = new Thread(r);

　　 thread.setUncaughtExceptionHandler((t, e) - {

　　 // 记录线程异常

　　 log.error(e.getMessage(), e);

　　 return thread;

　　ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(5, 10, 60,

　　 TimeUnit.SECONDS, new ArrayBlockingQueue (100000),

　　 threadFactory);

　　threadPoolExecutor.execute(() - {

　　 log.info("---------------------");

　　 int i = 1 / 0;

　　二. 线程池决绝策略设置错误导致业务接口执行超时

　　先介绍下线程池得四种决绝策略

　　AbortPolicy：丢弃任务并抛出RejectedExecutionException异常，这是线程池默认的拒绝策略

　　DiscardPolicy：丢弃任务，但是不抛出异常。如果线程队列已满，则后续提交的任务都会被丢弃，且是静默丢弃。

　　使用此策略，可能会使我们无法发现系统的异常状态。建议是一些无关紧要的业务采用此策略

　　DiscardOldestPolicy：丢弃队列最前面的任务，然后重新提交被拒绝的任务。此拒绝策略，是一种喜新厌旧的拒绝策略。是否要采用此种拒绝策略，还得根据实际业务是否允许丢弃老任务来认真衡量。

　　CallerRunsPolicy：由调用线程处理该任务

　　如下是一个线上业务接口使用得线程池配置，决绝策略采用 CallerRunsPolicy

// 某个线上线程池配置如下

　　ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(

　　 50, // 最小核心线程数

　　 50, // 最大线程数，当队列满时，能创建的最大线程数

　　 60L, TimeUnit.SECONDS, // 空闲线程超过核心线程时，回收该线程的最大等待时间

　　 new LinkedBlockingQueue (5000), // 阻塞队列大小,当核心线程使用满时，新的线程会放进队列

　　 new CustomizableThreadFactory("task"), // 自定义线程名

　　 new ThreadPoolExecutor.CallerRunsPolicy() // 线程执行的拒绝策略

　　在某些情况下，子线程任务调用第三方接口超时，导致核心线程数、最大线程数占满、阻塞队列占满的情况下执行拒绝策略时，由于使用 CallerRunsPolicy 策略，导致业务线程执行子任务时继续超时，进而导致接口执行异常，这种情况下，考虑到子线程任务得重要性，不是很重要得话，可以使用 DiscardPolicy 策略，要是很重要，可以发送到消息队列中持久化子线程任务数据待后续处理

　　三. 优雅的单例模式懒加载帮助类代码实现

　　博主推荐通过静态内部类实现单例模式，并实现懒加载效果，代码如下

// 使用静态内部类完成单例模式封装，避免线程安全问题，避免重复初始化成员属性

　　@Slf4j

　　publicclassFilterIpUtil{

　　privateFilterIpUtil(){

　　}

　　privateList String strings =newArrayList ();

　　 // 代码块在FilterIpUtil实例初始化时才会执行

　　{

　　 // 在代码块中完成文件的第一次读写操作，后续不再读这个文件

　　System.out.println("FilterIpUtil init");

　　try(InputStreamresourceAsStream=FilterIpUtil.class.getClassLoader().getResourceAsStream("filterIp.txt")) {

　　// 将文件内容放到string集合中

　　IoUtil.readUtf8Lines(resourceAsStream, strings);

　　}catch(IOException e) {

　　log.error(e.getMessage(), e);

　　}

　　publicstaticFilterIpUtilgetInstance(){

　　returnInnerClassInstance.instance;

　　}

　　// 使用内部类完成单例模式，由jvm保证线程安全

　　privatestaticclassInnerClassInstance{

　　privatestaticfinalFilterIpUtilinstance=newFilterIpUtil();

　　}

　　// 判断集合中是否包含目标参数

　　publicbooleanisFilter(String arg){

　　returnstrings.contains(arg);

　　}

　　四. 使用ip2region实现请求地址解析

　　在博主之前公司得项目中，ip解析是调用淘宝IP还有聚合IP接口获取结果，通常耗时200毫秒左右，并且接口不稳定时而会挂。都会影响业务接口耗时，后来在 github 上了解到 ip2region 这个项目，使用本地ip库查询，查询速度微秒级别，精准度能达到90%，但是ip库还是有少部分ip信息不准，建议数据库中把请求ip地址保存下来。简介如下：

　　ip2region v2.0 - 是一个离线IP地址定位库和IP定位数据管理框架，10微秒级别的查询效率，提供了众多主流编程语言的xdb数据生成和查询客户端实现基于 xdb文件的查询，下面是一个 Spring 项目中 ip2region 帮助类来实现ip地址解析

/**

　　 * ip2region工具类

　　@Slf4j

　　@Component

　　public class Ip2region {

　　 private Searcher searcher = null;

　　 @Value("${ip2region.path:}")

　　 private String ip2regionPath = "";

　　 @PostConstruct

　　 private void init() {

　　 // 1、从 dbPath 加载整个 xdb 到内存。

　　 String dbPath = ip2regionPath;

　　 // 1、从 dbPath 加载整个 xdb 到内存。

　　 byte[] cBuff;

　　 try {

　　 cBuff = Searcher.loadContentFromFile(dbPath);

　　 searcher = Searcher.newWithBuffer(cBuff);

　　 } catch (Exception e) {

　　 log.error("failed to create content cached searcher: {}", e.getMessage(), e);

　　 public IpInfoBean getIpInfo(String ip) {

　　 if (StringUtils.isBlank(ip)) {

　　 return null;

　　 // 3、查询

　　 try {

　　 long sTime = System.nanoTime();

　　 // 国家区域省份城市ISP

　　 String region = searcher.search(ip);

　　 long cost = TimeUnit.NANOSECONDS.toMicros((long) (System.nanoTime() - sTime));

　　 log.info("{region: {}, ioCount: {}, took: {} μs}", region, searcher.getIOCount(), cost);

　　 if (StringUtils.isNotBlank(region)) {

　　 String[] split = region.split("\");

　　 IpInfoBean ipInfo = new IpInfoBean();

　　 ipInfo.setIp(ip);

　　 if (!"".equals(split[0])) {

　　 ipInfo.setCountry(split[0]);

　　 if (!"".equals(split[2])) {

　　 ipInfo.setProvince(split[2]);

　　 if (!"".equals(split[3])) {

　　 ipInfo.setCity(split[3]);

　　 if (!"".equals(split[4])) {

　　 ipInfo.setIsp(split[4]);

　　 return ipInfo;

　　 } catch (Exception e) {

　　 log.error("failed to search({}): {}", ip, e);

　　 return null;

　　 // 4、关闭资源 - 该 searcher 对象可以安全用于并发，等整个服务关闭的时候再关闭 searcher

　　 // searcher.close();

　　 // 备注：并发使用，用整个 xdb 数据缓存创建的查询对象可以安全的用于并发，也就是你可以把这个 searcher 对象做成全局对象去跨线程访问。

　　 return null;

　　要注意得就是 ip2region v2.0 版本使用的xdb文件不建议放在项目 resources 下一起打包，存在编码格式问题，建议通过指定路径加载得方式单独放在服务器目录下

　　五. 优雅得Springboot + mybatis配置多数据源方式

　　Springboot + mybatis 得项目中一般通过 @MapperScan 注解配置 dao 层包目录，来实现 dao 层增强，其实项目中配置一个@MapperScan 是指定一个数据源，配置两个@MapperScan就可以指定两个数据源，通过不同得 dao 层包目录区分，来实现不同数据源得访问隔离。

　　比如下面代码中，com.xxx.dao.master 目录下为主数据源 dao 文件，com.xxx.dao.slave 为从数据源 dao 文件，这个方式比网上得基于 aop 加注解得方式更加简洁好用，也没有单个方法中使用不同数据源切换得问题，因此推荐这种写法

/**

　　 * 主数据源

　　@Slf4j

　　@Configuration

　　@MapperScan(basePackages = {"com.xxx.dao.master"},

　　 sqlSessionFactoryRef = "MasterSqlSessionFactory")

　　public class MasterDataSourceConfig {

　　 @Bean(name = "MasterDataSource")

　　 @Qualifier("MasterDataSource")

　　 @ConfigurationProperties(prefix = "spring.datasource.master")

　　 public DataSource clickHouseDataSource() {

　　 return DruidDataSourceBuilder.create().build();

　　 @Bean(name = "MasterSqlSessionFactory")

　　 public SqlSessionFactory getSqlSessionFactory(@Qualifier("MasterDataSource") DataSource dataSource) throws Exception {

　　 MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean();

　　 sessionFactoryBean.setDataSource(dataSource);

　　 sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()

　　 .getResources("classpath*:mapper/master/*.xml"));

　　 log.info("------------------------------------------MasterDataSource 配置成功");

　　 return sessionFactoryBean.getObject();

　　 * 从数据源

　　@Slf4j

　　@Configuration

　　@MapperScan(basePackages = {"com.xxx.dao.slave"},

　　 sqlSessionFactoryRef = "SlaveSqlSessionFactory")

　　public class MasterDataSourceConfig {

　　 @Bean(name = "SlaveDataSource")

　　 @Qualifier("SlaveDataSource")

　　 @ConfigurationProperties(prefix = "spring.datasource.slave")

　　 public DataSource clickHouseDataSource() {

　　 return DruidDataSourceBuilder.create().build();

　　 @Bean(name = "SlaveSqlSessionFactory")

　　 public SqlSessionFactory getSqlSessionFactory(@Qualifier("SlaveDataSource") DataSource dataSource) throws Exception {

　　 MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean();

　　 sessionFactoryBean.setDataSource(dataSource);

　　 sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()

　　 .getResources("classpath*:mapper/slave/*.xml"));

　　 log.info("------------------------------------------SlaveDataSource 配置成功");

　　 return sessionFactoryBean.getObject();

　　数据源yml配置

spring:

　　 datasource:

　　 type: com.alibaba.druid.pool.DruidDataSource

　　 driverClassName: com.mysql.cj.jdbc.Driver

　　 # 主库数据源

　　 master:

　　 url: jdbc:mysql://localhost:3306/db1?useUnicode=true characterEncoding=utf8 zeroDateTimeBehavior=convertToNull useSSL=true serverTimezone=GMT%2B8

　　 username: root

　　 password:

　　 slave:

　　 url: jdbc:mysql://localhost:3306/db2?useUnicode=true characterEncoding=utf8 zeroDateTimeBehavior=convertToNull useSSL=true serverTimezone=GMT%2B8

　　 username: root

　　 password:

　　博主刚开始编码一、两年得时候一个项目中遇到了多数据源使用得问题，那时候题主便在网上搜索Spring 多数据源得帖子，大多数都是基于Spring提供得AbstractRoutingDataSource + AOP + 注解来做动态切换，包括现在流行得 Mybatis plus 官方得多数据源解决方案也是这种做法，这种做法解决了博主当时得多数据源使用问题，后来加了一个需求，在一个定时任务中，查询两个数据源得数据，才发现动态切换在单个方法中不好用了，最后使用得原生jdbc数据源解决。多年后，博主在另一家公司得项目中又遇到了多数据源问题，但是这次博主在网上搜索得是Mybatis 多数据源，才发现了这个优雅得解决方案，进而推荐给大家

　　六. Spring Security项目中，使用MDC实现接口请求调用追踪，以及用户ID记录

　　MDC介绍

　　MDC(Mapped Diagnostic Context，映射调试上下文)是 log4j 、logback及log4j2 提供的一种方便在多线程条件下记录日志的功能。MDC可以看成是一个与当前线程绑定的哈希表，可以往其中添加键值对。MDC 中包含的内容可以被同一线程中执行的代码所访问。当前线程的子线程会继承其父线程中的 MDC 的内容。当需要记录日志时，只需要从 MDC 中获取所需的信息即可。

　　虽然MDC能够方便得实现接口请求调用追踪功能，但是它在子线程中会丢失父线程中添加得键值对信息，解决方法是通过父线程中调用线程池前调用 MDC.getCopyOfContextMap() ，然后在子线程中第一个调用 MDC.setConextMap() 获取键值对信息，完整实现代码如下：

/**

　　 * 自定义Spring线程池，解决子线程丢失reqest_id问题

　　public class ThreadPoolExecutorMdcWrapper extends ThreadPoolTaskExecutor {

　　 @Override

　　 public void execute(Runnable task) {

　　 super.execute(ThreadMdcUtil.wrap(task, MDC.getCopyOfContextMap()));

　　 @Override

　　 public T Future T submit(Callable T task) {

　　 return super.submit(ThreadMdcUtil.wrap(task, MDC.getCopyOfContextMap()));

　　 @Override

　　 public Future ? submit(Runnable task) {

　　 return super.submit(ThreadMdcUtil.wrap(task, MDC.getCopyOfContextMap()));

　　 * MDC帮助类，添加reqest_id

　　public class ThreadMdcUtil {

　　
public static T Callable T wrap(final Callable T callable, final Map String, String context) {

　　 return () - {

　　 if (context == null) {

　　 MDC.clear();

　　 } else {

　　 MDC.setContextMap(context);

　　 setTraceIdIfAbsent();

　　 try {

　　 return callable.call();

　　 } finally {

　　 MDC.clear();

　　 public static Runnable wrap(final Runnable runnable, final Map String, String context) {

　　 return () - {

　　 if (context == null) {

　　 MDC.clear();

　　 } else {

　　 MDC.setContextMap(context);

　　 // 设置traceId

　　 setTraceIdIfAbsent();

　　 try {

　　 runnable.run();

　　 } finally {

　　 MDC.clear();

　　在 Spring Security 中添加 token 过滤器

/**

　　 * token过滤器验证token有效性

　　 * @author ruoyi

　　@Slf4j

　　@Component

　　public class JwtAuthenticationTokenFilter extends OncePerRequestFilter {

　　 @Autowired

　　 private TokenService tokenService;

　　
@Override

　　 protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)

　　 throws ServletException, IOException {

　　 try {

　　 // 入口传入请求ID

　　 ThreadMdcUtil.setTraceIdIfAbsent();

　　 LoginUserDetail loginUser = tokenService.getLoginUser(request);

　　 if (Objects.nonNull(loginUser) Objects.isNull(SecurityContextHolder.getContext().getAuthentication())) {

　　 // 记录userId

　　 ThreadMdcUtil.setUserId(String.valueOf(loginUser.getMember().getId()));

　　 tokenService.verifyToken(loginUser);

　　 UsernamePasswordAuthenticationToken authenticationToken = new UsernamePasswordAuthenticationToken(loginUser, null, loginUser.getAuthorities());

　　 authenticationToken.setDetails(new WebAuthenticationDetailsSource().buildDetails(request));

　　 SecurityContextHolder.getContext().setAuthentication(authenticationToken);

　　 chain.doFilter(request, response);

　　 } finally {

　　 // 出口移除请求ID

　　 ThreadMdcUtil.removeTraceId();

　　最后在 logback.xml 中添加 %X{request_id}

 property name="pattern"

　　 value="%d{yyyy-MM-dd HH:mm:ss.SSS} [%X{request_id}] [%thread] [%-5level] %logger{36}:%L %M - %msg%n"/

　　日志打印效果如下：

2022-11-27 21:29:48.008 [86c76336100c414dbe9217aeb099ccd5_12] [http-nio-82-exec-2] [INFO ] c.w.m.a.s.impl.IHomeServiceImpl:56 getHomeIndexDataCompletableFuture - getHomeIndexDataCompletableFuture:com.wayn.common.util.R@701f7b8e[code=200,msg=操作成功,map={bannerList=[{"createTime":"2020-06-26 19:56:03","delFlag":false,"id":14,"imgUrl":"https://m.360buyimg.com/mobilecms/s700x280_jfs/t1/117335/39/13837/263099/5f291a83E8ba761d0/5c0460445cb28248.jpg!cr_1125x449_0_166!q70.jpg.dpg","jumpUrl":"http://82.157.141.70/mall/#/detail/1155015","sort":0,"status":0,"title":"hh2","updateTime":"2022-06-19 09:16:46"},{"createTime":"2020-06-26 19:56:03","delFlag":false,"id":15,"imgUrl":"https://m.360buyimg.com/mobilecms/s700x280_jfs/t1/202096/26/11652/265782/616acb67E4fcdc9ac/8d7cdfbb6c934e67.jpg!cr_1125x449_0_166!q70.jpg.dpg","jumpUrl":"#/detail/1155015","sort":0,"status":0,"title":"hh","updateTime":"2022-06-19 09:04:58"}], newGoodsList=[{"actualSales":0,"brandId":0,"brief":"酥脆奶香，甜酸回味","categoryId":1008015,"counterPrice":56.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1116011","id":1116011,"isHot":true,"isNew":true,"isOnSale":true,"keywords":"","name":"蔓越莓曲奇 200克","picUrl":"http://yanxuan.nosdn.127.net/767b370d07f3973500db54900bcbd2a7.png","retailPrice":36.00,"shareUrl":"","sort":5,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"粉彩色泽，记录生活","categoryId":1012003,"counterPrice":49.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1127047","id":1127047,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"趣味粉彩系列笔记本","picUrl":"http://yanxuan.nosdn.127.net/6c03ca93d8fe404faa266ea86f3f1e43.png","retailPrice":29.00,"shareUrl":"","sort":2,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"慢回弹海绵，时尚设计。","categoryId":1008002,"counterPrice":66.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1134030","id":1134030,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"简约知性记忆棉坐垫","picUrl":"http://yanxuan.nosdn.127.net/aa49dfe878becf768eddc4c1636643a6.png","retailPrice":46.00,"shareUrl":"","sort":12,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"慢回弹海绵的呵护，萌趣添彩。","categoryId":1008002,"counterPrice":69.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1134032","id":1134032,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"趣味粉彩系列记忆棉坐垫","picUrl":"http://yanxuan.nosdn.127.net/8b30eeb17c831eba08b97bdcb4c46a8e.png","retailPrice":49.00,"shareUrl":"","sort":13,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"100%桑蚕丝，丝滑润肤","categoryId":1008009,"counterPrice":2619.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1135002","id":1135002,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"宫廷奢华真丝四件套","picUrl":"http://yanxuan.nosdn.127.net/45548f26cfd0c7c41e0afc3709d48286.png","retailPrice":2599.00,"shareUrl":"","sort":1,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"自由海军领探索未来梦","categoryId":1020003,"counterPrice":89.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1135072","id":1135072,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"经典海魂纹水手裙（婴童）","picUrl":"http://yanxuan.nosdn.127.net/43e57d4208cdc78ac9c088f9b3e798f5.png","retailPrice":69.00,"shareUrl":"","sort":3,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"经典海魂纹自由海军领","categoryId":1020003,"counterPrice":89.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1135073","id":1135073,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"海魂纹哈衣水手服（婴童）","picUrl":"http://yanxuan.nosdn.127.net/53052b04ae001d289c040e09ea92231c.png","retailPrice":69.00,"shareUrl":"","sort":4,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":5,"brandId":0,"brief":"差旅好伴侣","categoryId":1032000,"counterPrice":119.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1152031","id":1152031,"isHot":true,"isNew":true,"isOnSale":true,"keywords":"","name":"魔兽世界-伊利丹颈枕眼罩套装","picUrl":"http://yanxuan.nosdn.127.net/fd6e78a397bd9e9804116a36f0270b0a.png","retailPrice":99.00,"shareUrl":"","sort":4,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":5,"brandId":0,"brief":"桌面整理神器","categoryId":1032000,"counterPrice":519.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1152095","id":1152095,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"魔兽世界 联盟·暴风城 堡垒收纳盒","picUrl":"http://yanxuan.nosdn.127.net/c86b49f635fa141decebabbd0966a6ef.png","retailPrice":499.00,"shareUrl":"","sort":6,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":0,"brandId":0,"brief":"3重透气，清爽柔滑","categoryId":1008009,"counterPrice":479.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1152161","id":1152161,"isHot":false,"isNew":true,"isOnSale":true,"keywords":"","name":"竹语丝麻印花四件套","picUrl":"http://yanxuan.nosdn.127.net/977401e75113f7c8334c4fb5b4bf6215.png","retailPrice":459.00,"shareUrl":"","sort":6,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10}], categoryList=[{"createTime":"2020-12-08 23:09:12","delFlag":false,"iconUrl":"http://cdn.wayn.xin/9fc3c52571aa38a1466f114c2dc892fc.png","id":2,"jumpType":0,"name":"大牌手机","picUrl":"http://cdn.wayn.xin/2545dd00ca4575759024af2811949a9d.jpg","sort":1,"status":0,"updateTime":"2020-12-12 19:26:48","valueId":5,"valueUrl":"http://baidu.com"},{"createTime":"2020-12-06 13:27:54","delFlag":false,"iconUrl":"http://82.157.141.70/upload/2022/02/21/a23fa32c8f4004a8c9fbbb1784462163.jpg","id":1,"jumpType":0,"name":"滋补保健2","picUrl":"http://cdn.wayn.xin/d4de7172eb7ae4178ae4dafd6a973d8f.jpg","sort":2,"status":0,"updateTime":"2022-06-19 09:17:20","valueId":2},{"createTime":"2020-12-08 23:26:15","delFlag":false,"iconUrl":"http://cdn.wayn.xin/6bc0f8a131d2d16b8fc2004d4aa4860c.png","id":3,"jumpType":1,"name":"不锈钢锅","picUrl":"http://cdn.wayn.xin/314d87257f7a2ff03d5f4c5183797912.jpg","sort":2,"status":0,"updateTime":"2020-12-12 19:27:24","valueId":1036000},{"createTime":"2020-12-12 19:28:08","delFlag":false,"iconUrl":"http://cdn.wayn.xin/5a90531d901529967885279d7dc826e1.png","id":14,"jumpType":0,"name":"进口牛奶","picUrl":"http://cdn.wayn.xin/0b1f6ab63d5e222c52c83a2d0581e44c.jpg","sort":3,"status":0,"valueId":5},{"createTime":"2020-12-12 19:28:33","delFlag":false,"iconUrl":"http://cdn.wayn.xin/33530951827ca7e59940d51cda537d84.png","id":15,"jumpType":0,"name":"量贩囤货","picUrl":"http://cdn.wayn.xin/bb6daee3b3e51c3008db97585249f513.jpg","sort":4,"status":0,"valueId":2},{"createTime":"2020-12-12 19:28:50","delFlag":false,"iconUrl":"http://cdn.wayn.xin/7d337f25111b263b29d5d12589015c46.png","id":16,"jumpType":0,"name":"清洁用品","picUrl":"http://cdn.wayn.xin/be8995bda39d03b17349b8ec0dcab3d5.jpg","sort":5,"status":0,"valueId":2},{"createTime":"2020-12-12 19:29:10","delFlag":false,"iconUrl":"http://cdn.wayn.xin/2e632ec0173bb477dcdb601495e0412a.png","id":17,"jumpType":0,"name":"洗护用品","picUrl":"http://cdn.wayn.xin/53fb88c9d1245caa882aa3fc29187d0b.jpg","sort":6,"status":0,"valueId":4},{"createTime":"2020-12-12 19:29:28","delFlag":false,"iconUrl":"http://cdn.wayn.xin/942323c0e74677cf2aa15f09a1e63bca.png","id":18,"jumpType":0,"name":"日用百货","picUrl":"http://cdn.wayn.xin/8587f91db2edcb43e57da9835cc7ec76.jpg","sort":7,"status":0,"valueId":2},{"createTime":"2020-12-12 19:29:46","delFlag":false,"iconUrl":"http://cdn.wayn.xin/18d9d860ba9b8b28522e050f11a8a8e0.png","id":19,"jumpType":0,"name":"明星乳胶","picUrl":"http://cdn.wayn.xin/65273c7fb2273e90958e92626248a90a.jpg","sort":8,"status":0,"valueId":6},{"createTime":"2020-12-12 19:30:15","delFlag":false,"iconUrl":"http://cdn.wayn.xin/7c790577afda91eebc3c95586e190957.png","id":20,"jumpType":0,"name":"口碑好物","picUrl":"http://cdn.wayn.xin/210011b35be4ceee39e6a466b40b8e22.jpg","sort":9,"status":0,"updateTime":"2021-04-01 20:13:08","valueId":5}], expire_time=1669549170235, hotGoodsList=[{"actualSales":1,"brandId":1001045,"brief":"一级桑蚕丝，吸湿透气柔软","categoryId":1036000,"counterPrice":719.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1006013","id":1006013,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"双宫茧桑蚕丝被 空调被","picUrl":"http://yanxuan.nosdn.127.net/583812520c68ca7995b6fac4c67ae2c7.png","retailPrice":699.00,"shareUrl":"","sort":7,"unit":"件","updateTime":"2021-08-08 11:19:36","virtualSales":10},{"actualSales":1,"brandId":1001045,"brief":"双层子母被，四季皆可使用","categoryId":1008008,"counterPrice":14199.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1006014","id":1006014,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"双宫茧桑蚕丝被 子母被","picUrl":"http://yanxuan.nosdn.127.net/2b537159f0f789034bf8c4b339c43750.png","retailPrice":1399.00,"shareUrl":"","sort":15,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":6,"brandId":1001000,"brief":"加大加厚，双色精彩","categoryId":1036000,"counterPrice":219.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1011004","id":1011004,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"色织精梳AB纱格纹空调被","picUrl":"http://yanxuan.nosdn.127.net/0984c9388a2c3fd2335779da904be393.png","retailPrice":199.00,"shareUrl":"","sort":2,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":6,"brandId":0,"brief":"共享亲密2人时光","categoryId":1008008,"counterPrice":219.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1019002","id":1019002,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"升级款护颈双人记忆枕","picUrl":"http://yanxuan.nosdn.127.net/0118039f7cda342651595d994ed09567.png","retailPrice":199.00,"shareUrl":"","sort":10,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":6,"brandId":0,"brief":"健康保护枕","categoryId":1008008,"counterPrice":119.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1019006","id":1019006,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"植物填充护颈夜交藤枕","picUrl":"http://yanxuan.nosdn.127.net/60c3707837c97a21715ecc3986a744ce.png","retailPrice":99.00,"shareUrl":"","sort":7,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":6,"brandId":0,"brief":"厚实舒适","categoryId":1008001,"counterPrice":59.00,"createTime":"2018-02-01 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00:00:00","delFlag":false,"goodsSn":"1027004","id":1027004,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"色织六层纱布夏凉被","picUrl":"http://yanxuan.nosdn.127.net/6252f53aaf36c072b6678f3d8c635132.png","retailPrice":249.00,"shareUrl":"","sort":3,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":32,"brandId":0,"brief":"原生苦荞，健康护颈","categoryId":1008008,"counterPrice":119.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1036002","id":1036002,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"高山苦荞麦枕","picUrl":"http://yanxuan.nosdn.127.net/ffd7efe9d5225dff9f36d5110b027caa.png","retailPrice":99.00,"shareUrl":"","sort":5,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10},{"actualSales":32,"brandId":0,"brief":"5cm记忆绵的亲密包裹","categoryId":1008008,"counterPrice":619.00,"createTime":"2018-02-01 00:00:00","delFlag":false,"goodsSn":"1037011","id":1037011,"isHot":true,"isNew":false,"isOnSale":true,"keywords":"","name":"安睡慢回弹记忆绵床垫","picUrl":"http://yanxuan.nosdn.127.net/a03ea6f4509439acdafcb7ceba1debe0.png","retailPrice":599.00,"shareUrl":"","sort":22,"unit":"件","updateTime":"2018-02-01 00:00:00","virtualSales":10}]}]

　　2022-11-27 21:29:48.336 [9d919fb6d33c4652ba28ff87ae210809_12] [http-nio-82-exec-3] [DEBUG] c.w.c.c.m.s.G.selectGoodsListPage_mpCount:137 debug - == Preparing: SELECT COUNT(*) AS total FROM shop_goods WHERE del_flag = 0 AND is_on_sale = 1

　　2022-11-27 21:29:48.387 [9d919fb6d33c4652ba28ff87ae210809_12] [http-nio-82-exec-3] [DEBUG] c.w.c.c.m.s.G.selectGoodsListPage_mpCount:137 debug - == Parameters:

　　2022-11-27 21:29:48.426 [9d919fb6d33c4652ba28ff87ae210809_12] [http-nio-82-exec-3] [DEBUG] c.w.c.c.m.s.G.selectGoodsListPage_mpCount:137 debug - == Total: 1

　　2022-11-27 21:29:48.430 [9d919fb6d33c4652ba28ff87ae210809_12] [http-nio-82-exec-3] [DEBUG] c.w.c.c.m.s.G.selectGoodsListPage:137 debug - == Preparing: select id, goods_sn, name, pic_url, counter_price, retail_price, actual_sales, virtual_sales from shop_goods WHERE del_flag = 0 and is_on_sale = 1 order by create_time desc LIMIT ?

　　2022-11-27 21:29:48.452 [9d919fb6d33c4652ba28ff87ae210809_12] [http-nio-82-exec-3] [DEBUG] c.w.c.c.m.s.G.selectGoodsListPage:137 debug - == Parameters: 6(Long)

　　2022-11-27 21:29:48.476 [9d919fb6d33c4652ba28ff87ae210809_12] [http-nio-82-exec-3] [DEBUG] c.w.c.c.m.s.G.selectGoodsListPage:137 debug - == Total: 6

　　最后分析上诉日志：通过86c76336100c414dbe9217aeb099ccd5实现接口调用追踪，通过12用户ID，实现用户调用追踪

　　七. alibaba excel导出时自定义格式转换优雅实现

　　官网介绍：EasyExcel 是一个基于Java的简单、省内存的读写Excel的开源项目。在尽可能节约内存的情况下支持读写百M的Excel。

　　EasyExcel 是 alibaba 出的一个基于 java poi 得excel通用处理类库，他的优势在于内存消耗。对比 easypoi 方案，EasyExcel 在内存消耗、知名度（大厂光环）上更出众些。

　　博主在使用过程中发现导出excel，官网对自定义格式字段提供了 converter 接口，但只简单提供了CustomStringStringConverter 类代码，达不到博主想要得优雅要求，如下：

public class CustomStringStringConverter implements Converter String {

　　 @Override

　　 public Class ? supportJavaTypeKey() {

　　 return String.class;

　　 @Override

　　 public CellDataTypeEnum supportExcelTypeKey() {

　　 return CellDataTypeEnum.STRING;

　　 * 这里读的时候会调用

　　 * @param context

　　 * @return

　　 @Override

　　 public String convertToJavaData(ReadConverterContext ? context) {

　　 return "自定义：" + context.getReadCellData().getStringValue();

　　 * 这里是写的时候会调用不用管

　　 * @return

　　 @Override

　　 public WriteCellData ? convertToExcelData(WriteConverterContext String context) {

　　 return new WriteCellData (context.getValue());

　　在以上代码中，打个比方想要实现性别字段得自定义格式转换，就需要在convertToExcelData方法中，添加如下代码

@Override

　　public WriteCellData ? convertToExcelData(WriteConverterContext String context) {

　　 String value = context.getValue();

　　 if ("man".equals(value)) {

　　 return new WriteCellData ("男");

　　 } else {

　　 return new WriteCellData ("女");

　　可以看到，非常得不优雅，对于这种类型字段，博主习惯使用枚举类来定义字段所有类型，然后将枚举类转换为 map(value,desc) 结构，就可以优雅得实现这个自定义格式得需求

/**

　　 * 一、先定义int字段抽象转换。

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