ShardingJdbc+Mybatis实现多数据源

Mybatis+多数据源

这个是对shardingjdbc应用的一个升级，如果对于shardingjdbc的整合还没看过之前的文章的，可以先看看文章https://blog.csdn.net/Think_and_work/article/details/137174049?spm=1001.2014.3001.5501

整合步骤

1、依赖

和全新项目的单数据源依赖的一样

2、mybatis使用数据源配置有两种方式

一种是使用注解的方式
一种是指定xml使用某个数据源

我们这里使用注解的方式进行配置

相关的类主要如下：

注解类DataSource

package com.walker.mybatissharding.config.druid;import java.lang.annotation.*;/*** 自定义多数据源切换注解* <p>* 优先级：先方法，后类，如果方法覆盖了类上的数据源类型，以方法的为准，否则以类上的为准** @author*/
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Inherited
public @interface DataSource {/*** 切换数据源名称*/DataSourceType value() default DataSourceType.MASTER;
}

枚举DataSourceType

package com.walker.mybatissharding.config.druid;/*** 数据源** @author*/
public enum DataSourceType {/*** 主库*/MASTER,/***  分表*/SHARDING,}

连接池配置信息

package com.walker.mybatissharding.config.druid;import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;/*** druid 配置属性** @author*/
@Configuration
public class DruidProperties
{@Value("${spring.datasource.initialSize}")private int initialSize;@Value("${spring.datasource.minIdle}")private int minIdle;@Value("${spring.datasource.maxActive}")private int maxActive;@Value("${spring.datasource.maxWait}")private int maxWait;@Value("${spring.datasource.timeBetweenEvictionRunsMillis}")private int timeBetweenEvictionRunsMillis;@Value("${spring.datasource.minEvictableIdleTimeMillis}")private int minEvictableIdleTimeMillis;@Value("${spring.datasource.maxEvictableIdleTimeMillis}")private int maxEvictableIdleTimeMillis;@Value("${spring.datasource.validationQuery}")private String validationQuery;@Value("${spring.datasource.testWhileIdle}")private boolean testWhileIdle;@Value("${spring.datasource.testOnBorrow}")private boolean testOnBorrow;@Value("${spring.datasource.testOnReturn}")private boolean testOnReturn;public DruidDataSource dataSource(DruidDataSource datasource){/** 配置初始化大小、最小、最大 */datasource.setInitialSize(initialSize);datasource.setMaxActive(maxActive);datasource.setMinIdle(minIdle);/** 配置获取连接等待超时的时间 */datasource.setMaxWait(maxWait);/** 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 */datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);/** 配置一个连接在池中最小、最大生存的时间，单位是毫秒 */datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);datasource.setMaxEvictableIdleTimeMillis(maxEvictableIdleTimeMillis);/*** 用来检测连接是否有效的sql，要求是一个查询语句，常用select 'x'。如果validationQuery为null，testOnBorrow、testOnReturn、testWhileIdle都不会起作用。*/datasource.setValidationQuery(validationQuery);/** 建议配置为true，不影响性能，并且保证安全性。申请连接的时候检测，如果空闲时间大于timeBetweenEvictionRunsMillis，执行validationQuery检测连接是否有效。 */datasource.setTestWhileIdle(testWhileIdle);/** 申请连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。 */datasource.setTestOnBorrow(testOnBorrow);/** 归还连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。 */datasource.setTestOnReturn(testOnReturn);return datasource;}
}

使用ThreadLocal存储数据源变量

package com.walker.mybatissharding.config.druid;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;/*** 数据源切换处理* * @author*/
public class DynamicDataSourceContextHolder
{public static final Logger log = LoggerFactory.getLogger(DynamicDataSourceContextHolder.class);/*** 使用ThreadLocal维护变量，ThreadLocal为每个使用该变量的线程提供独立的变量副本，*  所以每一个线程都可以独立地改变自己的副本，而不会影响其它线程所对应的副本。*/private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();/*** 设置数据源的变量*/public static void setDataSourceType(String dsType){log.info("切换到{}数据源", dsType);CONTEXT_HOLDER.set(dsType);}/*** 获得数据源的变量*/public static String getDataSourceType(){return CONTEXT_HOLDER.get();}/*** 清空数据源变量*/public static void clearDataSourceType(){CONTEXT_HOLDER.remove();}
}

继承AbstractRoutingDataSource

package com.walker.mybatissharding.config.druid;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;import javax.sql.DataSource;
import java.util.Map;/*** 动态数据源** @author*/// 继承AbstractRoutingDataSource
public class DynamicDataSource extends AbstractRoutingDataSource
{public DynamicDataSource(DataSource defaultTargetDataSource, Map<Object, Object> targetDataSources){
//        设置默认数据源super.setDefaultTargetDataSource(defaultTargetDataSource);
//        设置目标数据源 Mapsuper.setTargetDataSources(targetDataSources);
//super.afterPropertiesSet();}@Overrideprotected Object determineCurrentLookupKey(){return DynamicDataSourceContextHolder.getDataSourceType();}
}

切面类 DataSourceAspect

package com.walker.mybatissharding.config.druid;import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.MethodSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;import java.util.Objects;/*** 多数据源处理** @author*/
@Aspect
@Order(1)
@Component
public class DataSourceAspect {protected Logger logger = LoggerFactory.getLogger(getClass());@Pointcut("@annotation(com.walker.mybatissharding.config.druid.DataSource)"+ "|| @within(com.walker.mybatissharding.config.druid.DataSource)")public void dsPointCut() {}@Around("dsPointCut()")public Object around(ProceedingJoinPoint point) throws Throwable {DataSource dataSource = getDataSource(point);if (dataSource != null) {DynamicDataSourceContextHolder.setDataSourceType(dataSource.value().name());}try {return point.proceed();} finally {// 销毁数据源 在执行方法之后DynamicDataSourceContextHolder.clearDataSourceType();}}/*** 获取需要切换的数据源*/public DataSource getDataSource(ProceedingJoinPoint point) {MethodSignature signature = (MethodSignature) point.getSignature();DataSource dataSource = AnnotationUtils.findAnnotation(signature.getMethod(), DataSource.class);if (Objects.nonNull(dataSource)) {return dataSource;}return AnnotationUtils.findAnnotation(signature.getDeclaringType(), DataSource.class);}
}

DruidConfig 配置类

package com.walker.mybatissharding.config.druid;import cn.hutool.extra.spring.SpringUtil;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
import com.alibaba.druid.spring.boot.autoconfigure.properties.DruidStatProperties;
import com.alibaba.druid.util.Utils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;import javax.servlet.*;
import javax.sql.DataSource;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;/*** druid 配置多数据源** @author*/
@Slf4j
@Configuration
public class DruidConfig
{// 主库数据源@Bean@ConfigurationProperties("spring.datasource.master")public DataSource masterDataSource(DruidProperties druidProperties){DruidDataSource dataSource = DruidDataSourceBuilder.create().build();return druidProperties.dataSource(dataSource);}// 动态数据源@Bean(name = "dynamicDataSource")@Primarypublic DynamicDataSource dataSource(DataSource masterDataSource){Map<Object, Object> targetDataSources = new HashMap<>();// 将master加入targetDataSources.put(DataSourceType.MASTER.name(), masterDataSource);// 将sharding数据源加入setDataSource(targetDataSources, DataSourceType.SHARDING.name(), "shardingSphereDataSource");
//        默认走masterreturn new DynamicDataSource(masterDataSource, targetDataSources);}/*** 设置数据源** @param targetDataSources 备选数据源集合* @param sourceName 数据源名称* @param beanName bean名称*/public void setDataSource(Map<Object, Object> targetDataSources, String sourceName, String beanName){try{DataSource dataSource = SpringUtil.getBean(beanName);targetDataSources.put(sourceName, dataSource);}catch (Exception e){log.error("设置数据源失败",e);}}/*** 去除监控页面底部的广告*/@SuppressWarnings({ "rawtypes", "unchecked" })@Bean@ConditionalOnProperty(name = "spring.datasource.druid.statViewServlet.enabled", havingValue = "true")public FilterRegistrationBean removeDruidFilterRegistrationBean(DruidStatProperties properties){// 获取web监控页面的参数DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();// 提取common.js的配置路径String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*";String commonJsPattern = pattern.replaceAll("\\*", "js/common.js");final String filePath = "support/http/resources/js/common.js";// 创建filter进行过滤Filter filter = new Filter(){@Overridepublic void init(javax.servlet.FilterConfig filterConfig) throws ServletException{}@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)throws IOException, ServletException{chain.doFilter(request, response);// 重置缓冲区，响应头不会被重置response.resetBuffer();// 获取common.jsString text = Utils.readFromResource(filePath);
//                // 正则替换banner, 除去底部的广告信息
//                text = text.replaceAll("<a.*?banner\"></a><br/>", "");
//                text = text.replaceAll("powered.*?shrek.wang</a>", "");response.getWriter().write(text);}@Overridepublic void destroy(){}};FilterRegistrationBean registrationBean = new FilterRegistrationBean();registrationBean.setFilter(filter);registrationBean.addUrlPatterns(commonJsPattern);return registrationBean;}
}

3、application配置

server:port: 11001
spring:autoconfigure: # 排除druid 否则报错exclude: com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure
#  mybatis配置datasource:master:url: jdbc:mysql://localhost:3306/table_sharding?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=Asia/Shanghaiusername: rootpassword: 123456driver-class-name: com.mysql.cj.jdbc.Driver# 初始连接数initialSize: 5# 最小连接池数量minIdle: 10# 最大连接池数量maxActive: 20# 配置获取连接等待超时的时间maxWait: 60000# 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒timeBetweenEvictionRunsMillis: 60000# 配置一个连接在池中最小生存的时间，单位是毫秒minEvictableIdleTimeMillis: 300000# 配置一个连接在池中最大生存的时间，单位是毫秒maxEvictableIdleTimeMillis: 900000# 配置检测连接是否有效validationQuery: SELECT 1 FROM DUALtestWhileIdle: truetestOnBorrow: falsetestOnReturn: false# shardingsphere:# 开启sql打印enabled: trueprops:#　是否显示sqlsql-show: truedatasource:
#      数据源名称names: sharding
#      数据源实例：sharding:type: com.alibaba.druid.pool.DruidDataSourcedriver-class: com.mysql.cj.jdbc.Driver#        使用Druid，不能使用jdbc-url 得使用urlurl: jdbc:mysql://localhost:3306/table_sharding?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=Asia/Shanghaiusername: rootpassword: 123456
# 分片规则rules:sharding:
#        对表进行分片tables:
#          逻辑表名，代表的是需要分表的名称order_info:
#            实际节点：这里代表的是 会使用sharding数据源中 order_info表 细分为0~3 4个表actual-data-nodes: sharding.order_info_$->{0..3}
#            表策略table-strategy:
#              标准表策略standard:
#                分表的列sharding-column: id
#                分片算法名称： 来源于下面的sharding-algorithmssharding-algorithm-name: alg_hash_modkey-generate-strategy: # 主键生成策略column: id  # 主键列key-generator-name: snowflake  # 策略算法名称(推荐使用雪花算法)
#              主键生成规则，SNOWFLAKE 雪花算法key-generators:snowflake:type: SNOWFLAKE
#            分片算法sharding-algorithms:alg_hash_mod:
#            类型：hash取余  类似于获取一个列的数，假如是3  3%4=0 数据就会进入第0个表type: HASH_MOD
#            分片的数量，因为是4个表，所以是4props:sharding-count: 4mybatis:# 映射文件 配置之后，mybatis会去扫描该路径下的xml文件，才会与Mapper对应起来mapper-locations: classpath:mapper/*.xml
#  别名类(实体类)所在包type-aliases-package: com.walker.mybatissharding.entityconfiguration:# 打印日志log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
#    驼峰转换map-underscore-to-camel-case: true

4、测试类

entity类

package com.walker.mybatissharding.entity;import lombok.Data;import java.util.Date;/*** @Author: WalkerShen* @DATE: 2022/3/29* @Description:**/
@Data
public class OrderInfo {private Long id;private String name;private Integer num;private Date createTime;
}

Mapper

package com.walker.mybatissharding.mapper;import com.walker.mybatissharding.config.druid.DataSource;
import com.walker.mybatissharding.config.druid.DataSourceType;
import com.walker.mybatissharding.entity.OrderInfo;
import org.apache.ibatis.annotations.Mapper;import java.util.List;/*** @Author: WalkerShen* @DATE: 2022/3/29* @Description: 创建mapper接口，**///使用@Mapper，注入容器
@Mapper
public interface OrderInfoMapper {List<OrderInfo> list();//    使用指定的数据源，则使用注解标注，否则就走主数据源@DataSource(value = DataSourceType.SHARDING)List<OrderInfo> listSharding();}

mapper.xml

<?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">
<!--namespace：命名空间，用来映射对应的mapper
相当于将mapper和mapper.xml连接起来，这一步很重要-->
<mapper namespace="com.walker.mybatissharding.mapper.OrderInfoMapper"><select id="list" resultType="com.walker.mybatissharding.entity.OrderInfo">select * from order_info</select><select id="listSharding" resultType="com.walker.mybatissharding.entity.OrderInfo">select * from order_info</select></mapper>

测试类

package com.walker.mybatissharding;import com.walker.mybatissharding.entity.OrderInfo;
import com.walker.mybatissharding.mapper.OrderInfoMapper;
import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;import java.util.List;@Slf4j
@SpringBootTest
class MybatisShardingApplicationTests {@Autowiredprivate OrderInfoMapper orderInfoMapper;//    查 列表@Testvoid list() {List<OrderInfo> list = orderInfoMapper.list();System.out.println("返回结果："+list);}@Testvoid listSharding() {List<OrderInfo> list = orderInfoMapper.listSharding();System.out.println("返回结果："+list);}}