踩坑——纪实

1 npm安装

npm报错：request to https://registry.npm.taobao.org failed, reason certificate has expired

其实，早在2021年，淘宝就发文称，npm淘宝镜像已经从registry.npm.taobao.org切换到了registry.npmmirror.com。旧域名也将于2022年5月31日停止服务（不过，直到今天HTTPS证书到期才真正不能用了）

解决方案

1.1 查看当前的npm镜像设置

npm config list

1.2 清空缓存

npm cache clean --force

1.3 修改镜像

npm config set registry https://registry.npmmirror.com

1.4 查看修改结果

1.5 重新安装vue

npm install -g @vue/cli   #需要管理权限

vue3官网推荐在项目目录下执行：

npm create vue@latest

2 VScode——NPM脚本窗口找不到

设置→User→Extensions→Npm→勾选Enable Run From Folder

点击项目右上角的...，勾选NPM Scripts

3 springboot项目中updateById()失效

实体类继承自公共实体类BaseEntity，并将主键id放进去了，service方法调用getById正常，但是调用updateById时，传入一个json实体却获取不到id，这时，在id上添加注解：@JsonProperty("id")

@JsonProperty(“id”) //入参转换，为解决前端传入的json包无法接收
@JsonFiels(name = “id”) //出参转换

4 前端跨域

http://127.0.0.1:8001/admin/edu/teacher/list/1/5’ from origin ‘http://localhost:9528’ has been blocked by CORS policy: Response to preflight request doesn’t pass access control check: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

4.1 后端加个配置类

@Configuration
public class CorsConfig implements WebMvcConfigurer {@Overridepublic void addCorsMappings(CorsRegistry registry) {registry.addMapping("/**").allowedOriginPatterns("*") // 允许跨域的域名，*代表任何域名.allowedMethods("GET", "POST") // 允许的方法.allowedHeaders("*") // 允许任何请求头.allowCredentials(true) // 允许cookies/*.exposedHeaders(HttpHeaders.of("SET_COOKIE",fie))*/.maxAge(3600L);}
}

4.2 @CrossOrigin注解

也可以在Controller上添加该注解

5 路由出口

如果路由指向的页面组件是同一个，那么路由出口显示的页面组件不会重新渲染

为使重新渲染，需要为路由出口定义一个唯一key值

6 springdoc openapi3 swagger3文件上传

OpenAPI Specification - Version 3.1.0 | Swagger

#Considerations for File Uploads

In contrast with the 2.0 specification, input/output content in OpenAPI is described with the same semantics as any other schema type.file

In contrast with the 3.0 specification, the keyword has no effect on the content-encoding of the schema. JSON Schema offers a keyword, which may be used to specify the for the schema. The keyword supports all encodings defined in RFC4648, including “base64” and “base64url”, as well as “quoted-printable” from RFC2045. The encoding specified by the keyword is independent of an encoding specified by the header in the request or response or metadata of a multipart body – when both are present, the encoding specified in the is applied first and then the encoding specified in the header.format contentEncoding Content-Encoding contentEncoding contentEncoding Content-Type contentEncoding Content-Type

JSON Schema also offers a keyword. However, when the media type is already specified by the Media Type Object’s key, or by the field of an Encoding Object, the keyword SHALL be ignored if present.contentMediaType contentType contentMediaType

原来的写法：

public void upload(@RequestParam("file") MultipartFile file){}

3.0版本的写法：

public void upload(@RequestBody(content = @Content(mediaType = "multipart/form-data",schema = @Schema(type = "object"),schemaProperties = {@SchemaProperty(name = "file",schema = @Schema(type = "string",format = "binary"))})) MultipartFile file){}

7 连接mysql时出现[HY000][1130] null, message from server: “Host ‘‘ is not allowed报错

出现这个问题先考虑端口3306是否开通，如果开通还出现报错则开始下一步

解决这个问题有个很简单的方法就是先进入mysql然后命令

use mysql
update user set host='%' where user='root';

然后通过命令

GRANT ALL ON *.* TO 'root'@'%';
FLUSH PRIVILEGES;

8 Nacos2.2.3 启动成功但访问空白

修改conf/application.properties文件

### If turn on auth system:
nacos.core.auth.enabled=true### Since 1.4.1, worked when nacos.core.auth.enabled=true and nacos.core.auth.enable.userAgentAuthWhite=false.
### The two properties is the white list for auth and used by identity the request from other server.
#用户名
nacos.core.auth.server.identity.key=nacos
#密码
nacos.core.auth.server.identity.value=nacos### The default token (Base64 String):
nacos.core.auth.plugin.nacos.token.secret.key=SecretKey012345678901234567890123456789012345678901234567890123456789

9 ERROR StatusLogger Log4j2 could not find a logging imple mentation. Please add log4j-core to the classpath. Using SimpleLogger to log to the console…

添加依赖

<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>2.0.13</version>
</dependency><!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
<dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.23.1</version>
</dependency>

问题源自于easyexcel

<dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.3.4</version>
</dependency>

10 mapper.xml在pom文件中打包后找不到数据源配置了

mapper.xml文件在src/main/java/mapper/xml中，
在pom文件中添加了打包

<build><!-- 项目打包时会将java目录中的*.xml文件也进行打包 --><resources><resource><directory>src/main/java</directory><includes><include>**/*.*</include></includes><filtering>false</filtering></resource></resources>
</build>

但是添加后，application.yml就变红了，运行报错

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

尝试把resoources下的application.yml也打包到maven里，成功了。

<build><!-- 项目打包时会将java目录中的*.xml文件也进行打包 --><resources><resource><directory>src/main/java</directory><includes><include>**/*.xml</include></includes><filtering>false</filtering></resource><resource><directory>src/main/resources</directory><includes><include>**/*.yml</include></includes><filtering>false</filtering></resource></resources>
</build>

看来maven默认是都打包，但是如果我自定义的话就要全都定义了。

11 Refused to execute script from because its MIME type (‘text/html’) is not executable, and strict MIME type checking is enabled

每次打开前端，控制台都会报错，虽然不影响运行……

Refused to execute script from 'http://localhost:8080/something/index_bundle.js' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.

某度某应都试过了，无果。在StackOverflow搜索了下，方案：

Your webpack config is malformed. So your devServer is returning the fallback html file instead of the bundle.

Hence why the script is served with the (‘text/html’) MIME type.

devServer: {historyApiFallback:{index:'/dist/index.html'},}

You probably meant something like this:

devServer: {historyApiFallback: true
}

前端的工程只找到了webpack.dev.conf.js，果然有这一行，修改后，成功解决。

12 Nacos Whitelabel Error Page 503

Whitelabel Error Page

This application has no configured error view, so you are seeing this as a fallback.

Tue May 21 04:01:08 CST 2024

[9b38c884-1] There was an unexpected error (type=Service Unavailable, status=503).

用了负载均衡，控制台一路绿灯过去的，页面就是刷不出来，恼火。

查得，Nacos在2021版本起就删除了Ribbon的包，需要引入springcloud-loadbalancer

所以，依赖应该这么引：

<!-- nacos -->
<dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency><!-- loadbalancer -->
<dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-loadbalancer</artifactId>
</dependency>

13 Mybatis-Plus代码生成器

Spring Boot (v3.2.5)
mybatis-plus-generator (v3.5.6)

Mybatis-Plus代码生成器配置

14 @RequestBody

如果是来自springframework的注解，则会根据定义自动封装为Entity，

但如果是swagger的注解，没有传的参数就会自动填充为空。

比如User类的主键id设置了自增，前端传入的json中没有id值，如果是第一种，会自动封装；如果是第二种，数据库语句报错。