1.定义一个TenantLineHandler的实现类：

import com.baomidou.mybatisplus.extension.plugins.handler.TenantLineHandler; import com.google.common.collect.Lists; import net.sf.jsqlparser.expression.Expression; import net.sf.jsqlparser.expression.LongValue;  import java.util.List;  /**  * 多租户处理插件  *  * @author 向振华  * @date 2021/04/26 13:37  */ public class CustomTenantLineHandler implements TenantLineHandler {      /**      * 忽略添加租户ID的表      */     private final static List<String> IGNORE_TABLE_NAMES = Lists.newArrayList(             "t_country",             "t_language"     );      /**      * 获取租户ID值表达式(可从cookie、token、缓存中取)      *      * @return      */     @Override     public Expression getTenantId() {         return new LongValue(1L);     }      /**      * 获取租户字段名(数据库的租户ID字段名)      *      * @return      */     @Override     public String getTenantIdColumn() {         return "tenant_id";     }      /**      * 根据表名判断是否忽略拼接多租户条件      *      * @param tableName      * @return      */     @Override     public boolean ignoreTable(String tableName) {         return IGNORE_TABLE_NAMES.contains(tableName);     } }

2.定义MybatisPlusConfig配置类将多租户插件生效：

import com.baomidou.mybatisplus.annotation.DbType; import com.baomidou.mybatisplus.autoconfigure.ConfigurationCustomizer; import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor; import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor; import com.baomidou.mybatisplus.extension.plugins.inner.TenantLineInnerInterceptor; import com.bzcst.bop.component.mybatis.config.handler.CustomTenantLineHandler; import org.mybatis.spring.annotation.MapperScan; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;  /**  * @author 向振华  * @date 2021/04/26 14:45  */ @Configuration @MapperScan("scan.your.mapper.package") public class MybatisPlusConfig {      @Bean     public MybatisPlusInterceptor mybatisPlusInterceptor() {         MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();         // 多租户插件（注意：这个一定要放在最上面）         interceptor.addInnerInterceptor(new TenantLineInnerInterceptor(new CustomTenantLineHandler()));         // 分页插件         interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));         return interceptor;     }      @Bean     public ConfigurationCustomizer configurationCustomizer() {         return configuration -> configuration.setUseDeprecatedExecutor(false);     } }

测试

    @Test     public void select() {         Role role = roleService.getById(40L);         System.out.println(role);     }

Creating a new SqlSession SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@2fedfff1] was not registered for synchronization because synchronization is not active Original SQL: SELECT id,tenant_id,frame_id,name,type,description,meta_created,meta_updated,meta_logic_flag FROM t_sec_role WHERE id=?  parser sql: SELECT id, tenant_id, frame_id, name, type, description, meta_created, meta_updated, meta_logic_flag FROM t_sec_role WHERE id = ? AND tenant_id = 1 2021-04-26 14:58:55.534  INFO 24980 --- [           main] com.zaxxer.hikari.HikariDataSource       : DatebookHikariCP - Starting... 2021-04-26 14:58:55.903  INFO 24980 --- [           main] com.zaxxer.hikari.HikariDataSource       : DatebookHikariCP - Start completed. JDBC Connection [HikariProxyConnection@1100660981 wrapping com.mysql.cj.jdbc.ConnectionImpl@628fa8ea] will not be managed by Spring ==>  Preparing: SELECT id, tenant_id, frame_id, name, type, description, meta_created, meta_updated, meta_logic_flag FROM t_sec_role WHERE id = ? AND tenant_id = 1 ==> Parameters: 40(Long) <==    Columns: id, tenant_id, frame_id, name, type, description, meta_created, meta_updated, meta_logic_flag <==        Row: 40, 1, 123, 一个角色啊, 2, haha, 2021-04-26 14:07:42, 2021-04-26 14:07:42, 1 <==      Total: 1 Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@2fedfff1] Role(id=40, sasTenantId=1, orgFrameId=123, name=一个角色啊, type=2, description=haha, metaCreated=Mon Apr 26 14:07:42 CST 2021, metaUpdated=Mon Apr 26 14:07:42 CST 2021, metaLogicFlag=1)

可以看到查询语句后面拼接了tenant_id = 1

==>  Preparing: SELECT id, tenant_id, frame_id, name, type, description, meta_created, meta_updated, meta_logic_flag FROM t_sec_role WHERE id = ? AND tenant_id = 1

注意：如果表中没有定义tenant_id会报错，不需要添加多租户的表配置到CustomTenantLineHandler 中的IGNORE_TABLE_NAMES集合中