mybatis-generator:generate 生成代碼配置踩坑詳解

mybatis-generator:generate 生成代碼配置踩坑不少，在此留下筆記以便后續填坑

一、mysql返回時間問題

• 錯誤信息：

[ERROR] Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate (default-cli) on project coisini-mango-server: 
The server time zone value '???ú±ê×??±??' is unrecognized or represents more than one time zone.
You must configure either the server or JDBC driver (via the serverTimezone configuration property) 
to use a more specifc time zone value if you want to utilize time zone support. -> [Help 1]

JDBC需要配置服務器時區值， 在jdbc連接的url后面加上serverTimezone=GMT即可解決問題，如果使用GMT+8時區，需要寫成GMT%2B8，如下：

• application.properties的寫法：

url: jdbc:mysql://localhost:3306/coisini?useUnicode=true&zeroDateTimeBehavior=convertToNull&autoReconnect=true&characterEncoding=utf-8&serverTimezone=GMT%2B8

• generator.xml的寫法，注：在xml中寫&,會因為未轉義而報錯要將&寫成&

<jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1:3306/coisini?serverTimezone=GMT%2B8&amp;useUnicode=true&amp;characterEncoding=utf-8&amp;useSSL=false" userId="root" password="sunday"></jdbcConnection>

二、找不到數據庫連接驅動包

• 錯誤信息：

[ERROR] Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.2:generate (default-cli)
on project coisini-mango-server: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-
plugin:1.3.2:generate failed: Exception getting JDBC Driver: com.mysql.cj.jdbc.Driver -> [Help 1]

關於這個異常，網上大多數說在generatorConfig.xml中加入數據庫驅動包的絕對路徑，
方法一：

<classPathEntry  location="G:\Program Files\java\apache-maven-3.6.1\repository\mysql\mysql-connector-java\8.0.13\mysql-connector-java-8.0.13.jar"/>

采用絕對路徑后，編譯會報一個棄用警告

• 警告信息：

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. 
The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.

這里就引出了我們解決找不到數據庫連接驅動包的辦法，
方法二：

• 更改mysql驅動類為com.mysql.cj.jdbc.Driver，application.properties和generator.xml都要改
• 在pom.xml中plugin節點下添加mysql-connector-java的dependency

<plugin>
    <groupId>org.mybatis.generator</groupId>
     <artifactId>mybatis-generator-maven-plugin</artifactId>
     <version>1.3.2</version>
     <configuration>
         <configurationFile>src/main/resources/generator/generator.xml</configurationFile>
         <overwrite>true</overwrite>
         <verbose>true</verbose>
     </configuration>
 </plugin>

spring boot本就是通過maven自動配置，這里建議采用方法二，不建議使用配置絕對路徑。

詳細代碼移步：mybatis 生成代碼配置 mybatis-generator:generate 的使用詳解