Mybatis-Plus动态表名的实现示例

<dependency>
	<groupId>com.baomidou</groupId>
	<artifactId>mybatis-plus-boot-starter</artifactId>
	<version>3.5.1</version>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>8.0.28</version>
</dependency>

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/db1?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai&useSSL=false
    username: root
    password: 123456
    driver-class-name: com.mysql.cj.jdbc.Driver

@Data
@TableName("t_user")
public class User {
    @TableId(type = IdType.AUTO)
    private Integer id;
    @TableField("name")
    private String name;
}

@Mapper
public interface UserMapper extends BaseMapper<User> {
	// 方法1
	@Select("Select * from ${tableName}")
	List<User> getUserInfo(@Param("tableName") String tableName);
	// 方法2
	List<User> getUserInfoMP(String tableName);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.xx.xx.mapper.UserMapper">
 <select id="getUserInfoMP" resultType="com.xx.xx.entity.User" >
        select * from ${tableName} order by phone_number ASC
 </select>
</mapper>

@Service
public class UserServiceImpl implements UserService {

	@Autowired
    private UserMapper userMapper;
	
	void query(){
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
        String rDay = LocalDateTime.now().format(formatter);
		String tableName = "t_user_" + rDay;
		
		List<User> list1 = userMapper.getUserInfo(tableName);
		List<User> list2 = userMapper.getUserInfoMP(tableName);
	}

}

@Configuration
@MapperScan(basePackages = {"com.xx.**.mapper"})
public class MybatisPlusConfig {

    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
        //动态表名
        DynamicTableNameInnerInterceptor dynamicTableNameInnerInterceptor = new DynamicTableNameInnerInterceptor();
        //可以传多个表名参数，指定哪些表使用DayTableNameHandler处理表名称
        dynamicTableNameInnerInterceptor.setTableNameHandler(new DayTableNameHandler("t_user"));
		//以拦截器的方式处理表名称
		//可以传递多个拦截器，即：可以传递多个表名处理器TableNameHandler
        mybatisPlusInterceptor.addInnerInterceptor(dynamicTableNameInnerInterceptor);
        return mybatisPlusInterceptor;
    }
}

/**
 * 按天参数，组成动态表名
 */
public class DayTableNameHandler implements TableNameHandler {
    //用于记录哪些表可以使用该动态表名处理器（即哪些表需要分表）
    private List<String> tableNames;
    //构造函数，构造动态表名处理器的时候，传递tableNames参数
    public DayTableNameHandler(String ...tableNames) {
        this.tableNames = Arrays.asList(tableNames);
    }
    //每个请求线程维护一个day数据，避免多线程数据冲突。所以使用ThreadLocal
    private static final ThreadLocal<String> DAY_DATA = new ThreadLocal<>();
    //设置请求线程的day数据
    public static void setData(String day) {
        DAY_DATA.set(day);
    }
    //删除当前请求线程的day数据
    public static void removeData() {
        DAY_DATA.remove();
    }
    //动态表名接口实现方法
    @Override
    public String dynamicTableName(String sql, String tableName) {
        if (this.tableNames.contains(tableName)){
            return tableName + "_" + DAY_DATA.get();  //表名增加后缀
        }else{
            return tableName;   //表名原样返回
        }
    }
}

@Service
public class UserServiceImpl implements UserService {

	@Autowired
    private UserService userService;
	
	void query(){
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
        String rDay = LocalDateTime.now().format(formatter);
        DayTableNameHandler.setData(rDay);
        List<User> list = userService.list();
        // 用完即销毁
        DayTableNameHandler.removeData();
	}
}

@Configuration
@MapperScan(basePackages = {"com.xx.**.mapper"})
public class MybatisPlusConfig {

	public static ThreadLocal<String> myTableName = new ThreadLocal<>();

    public MybatisPlusInterceptor mybatisPlusInterceptor(){
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
        //动态表名
        DynamicTableNameInnerInterceptor dynamicTableNameInnerInterceptor = new DynamicTableNameInnerInterceptor();
        HashMap<String, TableNameHandler> map = new HashMap<String, TableNameHandler>(2) {{
            put("t_user", (sql, tableName) -> {
                return myTableName.get();
            });
        }};
        dynamicTableNameInnerInterceptor.setTableNameHandlerMap(map);
        mybatisPlusInterceptor.addInnerInterceptor(dynamicTableNameInnerInterceptor);
		myTableName.remove();

        return mybatisPlusInterceptor;
    }
}

@Service
public class UserServiceImpl implements UserService {

	@Autowired
    private UserService userService;
	
	void query(){
		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
        String rDay = LocalDateTime.now().format(formatter);
        DayTableNameHandler.setData(rDay);
        String tableName = "t_user" + rDay;
        MybatisPlusConfig.myTableName.set(tableName);
        List<User> list = userService.list();        
	}
}