springboot整合 mybatis.generator

一、先记录正确配置

1、pom.xml添加依赖

　　　　　<dependency>
            <groupId>org.mybatis.spring.bootgroupId>
            <artifactId>mybatis-spring-boot-starterartifactId>
            <version>1.3.2version>
        dependency>
        <dependency>
            <groupId>mysqlgroupId>
            <artifactId>mysql-connector-javaartifactId>
            <version>8.0.23version>
        dependency>
        <dependency>
            <groupId>tk.mybatisgroupId>
            <artifactId>mapperartifactId>
            <version>4.1.5version>
        dependency>

　　　　　　　<plugin>
                <groupId>org.mybatis.generatorgroupId>
                <artifactId>mybatis-generator-maven-pluginartifactId>
                <version>1.3.7version>
                <configuration>
                    <configurationFile>${basedir}/src/main/resources/generator/generatorConfig.xmlconfigurationFile>
                    <overwrite>trueoverwrite>
                    <verbose>trueverbose>
                configuration>
                <dependencies>
                    <dependency>
                        <groupId>mysqlgroupId>
                        <artifactId>mysql-connector-javaartifactId>
                        <version>8.0.23version>
                    dependency>
                    <dependency>
                        <groupId>tk.mybatisgroupId>
                        <artifactId>mapperartifactId>
                        <version>4.1.5version>
                    dependency>
                dependencies>
            plugin>

2、维护generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <classPathEntry
            location="E:\mysql-connector-java-8.0.23.jar" />

    <context id="Mysql" targetRuntime="MyBatis3Simple" defaultModelType="flat">
        <property name="javaFileEncoding" value="UTF-8"/>
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>
        <plugin type="tk.mybatis.mapper.generator.MapperPlugin">
            <property name="mappers" value="tk.mybatis.mapper.common.Mapper"/>
            <property name="caseSensitive" value="true"/>
        plugin>
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/aaaa"
                        userId="root"
                        password="root">
            <property name="nullCatalogMeansCurrent" value="true" />
        jdbcConnection>

        <javaModelGenerator targetPackage="com.xiufengd.domain"
                            targetProject="src/main/java"/>
        <sqlMapGenerator targetPackage="mapper"
                         targetProject="src/main/resources"/>
        <javaClientGenerator targetPackage="com.xiufengd.mapper"
                             targetProject="src/main/java"
                             type="XMLMAPPER"/>
        <table tableName="sys_user">
            <generatedKey column="id_" sqlStatement="JDBC"/>
        table>
    context>
generatorConfiguration>

3、运行

 得到正确结果，目录结构如下

 二、记录问题点

　　1、mybatis-generator-maven-plugin用版本1.3.7,用最新的1.4.0会出错，错误如下：

Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.4.0:generate (default-cli) on project itoken-service-admin: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.4.0:generate failed: A required class was missing while executing org.mybatis.generator:mybatis-generator-maven-plugin:1.4.0:generate: org/mybatis/generator/api/dom/xml/Element

　　2、application中扫描mapper应该用 import tk.mybatis.spring.annotation.MapperScan 而不是 org.mybatis.spring.annotation.MapperScan,否则会报错，错误如下：

java.lang.NoSuchMethodException: tk.mybatis.mapper.provider.base.BaseSelectProvider

　　3、当连接中存在好多个数据库时，加载的表是第一个数据库的同名表，而不是指定数据库的，即 generator 链接数据库不对，此时应该在中添加配置

<property name="nullCatalogMeansCurrent" value="true" />

原因官方文档给出了解释 http://mybatis.org/generator/usage/mysql.html

谷歌翻译为：

 三、总结

　　1、有些框架真不是越新了越好，如果追求稳定还是用相对稳定的版本。

　　2、多看官方文档、官方文档很多时候给了解决方案了。