mysql5.7 字符集utf8mb4的默认排序规则为utf8mb4_general_ci
mysql8 字符集utf8mb4的默认排序规则为utf8mb4_0900_ai_ci

mysql5.7升级为mysql8后更改字符集和排序规则方式有以下几种

1. 只修改库字符集和排序规则

   ALTER DATABASE database_name CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci;

2. 只更改表字符集和排序规则

   ALTER TABLE table_name CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci;

3. 只更改字段字符集和排序规则

   ALTER TABLE table_name CHANGE COLUMN column_name varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NULL COMMENT '字段备注';
   

4. 同时更改表和改表下所有字段字符集和排序规则

ALTER TABLE table_name CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci;

&，./test &

一般在执行shell命令的时候我们在命令的后面加上一个‘&’，这样就可以使得该程序在后台运行，但是当程序运行起来之后依旧会再次在shell中输出打印信息，shell依旧被占用，关闭shell则程序退出；这个时候我们可以使用ctrl+z命令，使得这个信息消失，可以做别的事情，但是关闭shell的时候程序依旧会退出

./test >> out.txt 2>&1 & 

2>&1是指将标准错误重定向到标准输出，于是标准错误和标准输出都重定向到指定的out.txt文件中，从此终端彻底清静了。

nohup ./test &
nohup ./test > myout.txt 2>&1 &
nohup -c ./test > myout.txt 2>&1 &

nohup打日志不实时，可以加-c让日志实时写到文件

父pom引用

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

子工程eureka中引用

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
</dependency>

这时启动eureka时报错

xception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.cloud.netflix.eureka.server.EurekaServerInitializerConfiguration': Unsatisfied dependency expressed through field 'eurekaServerBootstrap'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'eurekaServerBootstrap' defined in class path resource [org/springframework/cloud/netflix/eureka/server/EurekaServerAutoConfiguration.class]: Unsatisfied dependency expressed through method 'eurekaServerBootstrap' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'eurekaServerContext': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: com/sun/jersey/client/apache4/ApacheHttpClient4

Spring Cloud 2020版本开始 Bootstrap上下文默认不再启动，改为了spring.config.import的方式，如需开启bootstrap启动方式，有两种方式：

设置值spring.cloud.bootstrap.enabled=true或者 spring.config.use-legacy-processing=true。
注意：这些个属性值必须确保其能放进环境里才能生效。比如：环境变量，系统属性，命令行等

引入一个spring-cloud-starter-bootstrap

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-bootstrap</artifactId>
</dependency>

A vuepress plugin for generate static post link based on post file name.

安装

npm install vuepress-plugin-shortlink --save

从config.js配置中删除 permalink，该插件是基于默认永久链接/:regular

例子

version 1.0

source: /books/a-book.md
permalink: /books/261f97f7.html

source: /hello-word.md
permalink: /b1d4025b.html

source: /books/computer/a-book.md
permalink: /books/computer/261f97f7.html

设定参数

该插件基于vuepress-plugin-clean-urls，可以自定义后缀和404，设定方法同vuepress-plugin-clean-urls

plugins: [
    [
      'vuepress-plugin-shortlink',
      {
        normalSuffix: '/',
        indexSuffix: '/',
        notFoundPath: '/404.html'
      },
    ],
  ],

version 1.1

增加配置containDirs
可设定只当文件夹全路径，其余只保留文件路径

plugins: [
    [
      'vuepress-plugin-shortlink',
      {
        normalSuffix: '/',
        indexSuffix: '/',
        notFoundPath: '/404.html',
        containDirs: ['/books']
      },
    ],
  ],

地址展示

source: /books/a-book.md
permalink: /books/261f97f7/

source: /hello-word.md
permalink: /b1d4025b/

source: /say/hello-word.md
permalink: /b1d4025b/

source: /books/computer/a-book.md
permalink: 261f97f7/

ThanksFor

vuepress-plugin-clean-urls sheetjs