<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
	<version>2.4.2</version>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>${mysql-connector.version}</version>
</dependency>
<dependency>
	<groupId>com.baomidou</groupId>
	<artifactId>mybatis-plus-boot-starter</artifactId>
	<version>${mybatis-plus.version}</version>
</dependency>

#數(shù)據(jù)源master
spring.dynamic.datasource.master.url = jdbc:mysql://127.0.0.1:3306/aaa?characterEncoding=utf-8&rewriteBatchedStatements=true&tinyInt1isBit=false&allowMultiQueries=true
spring.dynamic.datasource.master.username = root
spring.dynamic.datasource.master.password = xxxxxxxx
spring.dynamic.datasource.master.driver-class-name = com.mysql.cj.jdbc.Driver
spring.dynamic.datasource.master.type = com.zaxxer.hikari.HikariDataSource
#數(shù)據(jù)源slave
spring.dynamic.datasource.slave.url = jdbc:mysql://127.0.0.1:3306/bbb?characterEncoding=utf-8&rewriteBatchedStatements=true&tinyInt1isBit=false&allowMultiQueries=true
spring.dynamic.datasource.slave.username = root
spring.dynamic.datasource.slave.password = yyyyyyyy
spring.dynamic.datasource.slave.driver-class-name = com.mysql.cj.jdbc.Driver
spring.dynamic.datasource.slave.type = com.zaxxer.hikari.HikariDataSource

import lombok.Data;
import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
import org.springframework.boot.context.properties.ConfigurationProperties;
import java.util.Map;
@Data
@ConfigurationProperties(prefix = "spring.dynamic")
public class DSProperties {
    private Map<String, DataSourceProperties> datasource;
}

 
import com.xxx.gateway.common.Constant;
import lombok.extern.slf4j.Slf4j;
@Slf4j
public class DynamicDataSourceHolder {
    /**
     * 保存動(dòng)態(tài)數(shù)據(jù)源名稱
     */
    private static final ThreadLocal<String> DYNAMIC_DATASOURCE_KEY = new ThreadLocal<>();
    /**
     * 設(shè)置/切換數(shù)據(jù)源，決定當(dāng)前線程使用哪個(gè)數(shù)據(jù)源
     */
    public static void setDynamicDataSourceKey(String key){
        log.info("數(shù)據(jù)源切換為：{}",key);
        DYNAMIC_DATASOURCE_KEY.set(key);
    }
    /**
     * 獲取動(dòng)態(tài)數(shù)據(jù)源名稱，默認(rèn)使用mater數(shù)據(jù)源
     */
    public static String getDynamicDataSourceKey(){
        String key = DYNAMIC_DATASOURCE_KEY.get();
        return key == null ? Constant.MASTER_DATASOURCE : key;
    }
    /**
     * 移除當(dāng)前數(shù)據(jù)源
     */
    public static void removeDynamicDataSourceKey(){
        log.info("移除數(shù)據(jù)源：{}",DYNAMIC_DATASOURCE_KEY.get());
        DYNAMIC_DATASOURCE_KEY.remove();
    }
}

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        String dataBaseType = DynamicDataSourceHolder.getDynamicDataSourceKey();
        return dataBaseType;
    }
}

 
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import java.util.HashMap;
import java.util.Map;
@Configuration
@EnableConfigurationProperties(DSProperties.class)
@MapperScan(basePackages = {"com.xxx.gateway.mapper"},
        sqlSessionFactoryRef = "SqlSessionFactory")
public class DynamicDataSourceConfig {
    @Bean(name = "dynamicDataSource")
    public DynamicDataSource DataSource(DSProperties dsProperties) {
        Map targetDataSource = new HashMap<>(8);
        dsProperties.getDatasource().forEach((k, v) -> {
            targetDataSource.put(k, v.initializeDataSourceBuilder().build());
        });
        DynamicDataSource dataSource = new DynamicDataSource();
        dataSource.setTargetDataSources(targetDataSource);
        return dataSource;
    }
    /**
     * 創(chuàng)建動(dòng)態(tài)數(shù)據(jù)源的SqlSessionFactory，傳入的是動(dòng)態(tài)數(shù)據(jù)源
     * @Primary這個(gè)注解很重要，如果項(xiàng)目中存在多個(gè)SqlSessionFactory，這個(gè)注解一定要加上
     */
    @Primary
    @Bean("SqlSessionFactory")
    public SqlSessionFactory sqlSessionFactoryBean(DynamicDataSource dynamicDataSource) throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dynamicDataSource);
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setMapUnderscoreToCamelCase(true);
        configuration.setDefaultFetchSize(100);
        configuration.setDefaultStatementTimeout(30);
        sqlSessionFactoryBean.setMapperLocations(
                new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*.xml"));
        sqlSessionFactoryBean.setConfiguration(configuration);
        return sqlSessionFactoryBean.getObject();
    }
    /**
     * 重寫事務(wù)管理器，管理動(dòng)態(tài)數(shù)據(jù)源
     */
    @Primary
    @Bean(value = "transactionManager")
    public PlatformTransactionManager annotationDrivenTransactionManager(DynamicDataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

import java.lang.annotation.*;
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DS {
    String value() default Constant.MASTER_DATASOURCE;
}

import com.xxx.gateway.config.DynamicDataSourceHolder;
import lombok.extern.slf4j.Slf4j;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.*;
import org.aspectj.lang.reflect.MethodSignature;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import java.util.Objects;
@Aspect
@Order(1)
@Component
@Slf4j
public class DsAspect {
    @Pointcut("@annotation(com.xgd.gateway.aspect.DS)")
    public void dsPointCut() {
    }
    //環(huán)繞通知
    @Around("dsPointCut()")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable{
        String key = getDefineAnnotation(joinPoint).value();
        DynamicDataSourceHolder.setDynamicDataSourceKey(key);
        try {
            return joinPoint.proceed();
        } finally {
            DynamicDataSourceHolder.removeDynamicDataSourceKey();
        }
    }
    /**
     * 先判斷方法的注解，后判斷類的注解，以方法的注解為準(zhǔn)
     * @param joinPoint
     * @return
     */
    private DS getDefineAnnotation(ProceedingJoinPoint joinPoint){
        MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
        DS dataSourceAnnotation = methodSignature.getMethod().getAnnotation(DS.class);
        if (Objects.nonNull(methodSignature)) {
            return dataSourceAnnotation;
        } else {
            Class<?> dsClass = joinPoint.getTarget().getClass();
            return dsClass.getAnnotation(DS.class);
        }
    }
}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.xxx.gateway.aspect.DS;
import com.xxx.gateway.domain.User;
import org.apache.ibatis.annotations.Param;
import java.util.List;
public interface UserMapper extends BaseMapper<User> {
    public User queryByCode(@Param("code") String code);
    @DS(value="master")
    public User queryByCodeNoPass(@Param("code") String code);
    @DS(value="slave1")
    public List<String> queryBanks();
}