mybatis-plus的 mapper.xml 路径配置的坑

spring boot整合mybatis-plus使用mysql和Oracle多数据源的时候，遇到如下问题:

mybatis-plus今天遇到一个问题，就是mybatis 没有读取到mapper.xml 文件。

特此记录一下，问题如下：

org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.husy.mapper.SystemUserMapper.findUserByName

    at com.baomidou.mybatisplus.core.override.MybatisMapperMethod$SqlCommand.<init>(MybatisMapperMethod.java:242)
    at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.<init>(MybatisMapperMethod.java:54)
    at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.lambda$cachedMapperMethod$0(MybatisMapperProxy.java:65)
    at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660)
    at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.cachedMapperMethod(MybatisMapperProxy.java:65)
    at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:60)
    at com.sun.proxy.$Proxy72.findUserByName(Unknown Source)
    at com.husy.service.impl.SystemUserServiceImpl.findUserByName(SystemUserServiceImpl.java:23)

首先我放xml的包的是没问题的，而是引入的架包和配置问题，问题配置如下:

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.msl.moniter.entity

解决方法：请将mybatis-plus改成mybatis,mybatis,mybtis,重要的说三遍，

必要的架包如下

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.1.2</version>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-core</artifactId>
    <version>3.1.2</version>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-autoconfigure</artifactId>
    <version>2.1.0</version>
</dependency>

注意第一个是mybatis-spring-boot-start ,不是mybatisplus-spring-boot-start

还要在mybatis配置文件里声明MybatisSqlSessionFactoryBean，至此问题解决

@Configuration
public class MybatisPlusConfig {
    @Autowired
    private DataSource dataSource;

    @Autowired
    private MybatisProperties properties;

    @Autowired
    private ResourceLoader resourceLoader = new DefaultResourceLoader();

    @Autowired(required = false)
    private Interceptor[] interceptors;

    @Autowired(required = false)
    private DatabaseIdProvider databaseIdProvider;

    /**
     *   mybatis-plus分页插件
     */
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        PaginationInterceptor page = new PaginationInterceptor();
        page.setDialectType("mysql");
        return page;
    }
    /**
     * 这里全部使用mybatis-autoconfigure 已经自动加载的资源。不手动指定
     * 配置文件和mybatis-boot的配置文件同步
     * @return
     */
    @Bean
    public MybatisSqlSessionFactoryBean mybatisSqlSessionFactoryBean() {
        MybatisSqlSessionFactoryBean mybatisPlus = new MybatisSqlSessionFactoryBean();
        mybatisPlus.setDataSource(dataSource);
        mybatisPlus.setVfs(SpringBootVFS.class);
        if (StringUtils.hasText(this.properties.getConfigLocation())) {
            mybatisPlus.setConfigLocation(this.resourceLoader.getResource(this.properties.getConfigLocation()));
        }
        mybatisPlus.setConfiguration(properties.getConfiguration());
        if (!ObjectUtils.isEmpty(this.interceptors)) {
            mybatisPlus.setPlugins(this.interceptors);
        }
        MybatisConfiguration mc = new MybatisConfiguration();
        mc.setDefaultScriptingLanguage(MybatisXMLLanguageDriver.class);
        mybatisPlus.setConfiguration(mc);
        if (this.databaseIdProvider != null) {
            mybatisPlus.setDatabaseIdProvider(this.databaseIdProvider);
        }
        if (StringUtils.hasLength(this.properties.getTypeAliasesPackage())) {
            mybatisPlus.setTypeAliasesPackage(this.properties.getTypeAliasesPackage());
        }
        if (StringUtils.hasLength(this.properties.getTypeHandlersPackage())) {
            mybatisPlus.setTypeHandlersPackage(this.properties.getTypeHandlersPackage());
        }
        if (!ObjectUtils.isEmpty(this.properties.resolveMapperLocations())) {
            mybatisPlus.setMapperLocations(this.properties.resolveMapperLocations());
        }
        return mybatisPlus;
    }
}

不知道是造作不正确还是jar问题，如下验证没有通过

经过查阅：

• 如果引用mybatis-plus-boot-starter 依赖，需要配置 mybatis-plus.mapper-locations
• 如果引用mybatis-plus 依赖，需要配置 mybatis.mapper-locations

参考：

https://blog.csdn.net/u013234928/article/details/94060733

https://blog.csdn.net/qq_21747795/article/details/81217264