记录一下java开发中多数据源的配置过程,
参考博客:https://blog.****.net/weinichendian/article/details/72903757,我在这里进行了整理,使用yml;排除了里边在springboot2.0报错的内容,以及里边没有说太清楚的内容,进行了详细的说明
1.配置文件application.yml
personnel:#数据源1
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://localhost:3307/person?useSSL=false&useUnicode=true&characterEncoding=utf8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC&allowMultiQueries=true&allowPublicKeyRetrieval=true
username: root
password: *******
userauth:#数据源2
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://localhost:3307/user?useSSL=false&useUnicode=true&characterEncoding=utf8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC&allowMultiQueries=true&allowPublicKeyRetrieval=true
username: root
password: ******
2.不同数据源枚举:
public enum DataSourceEnum {master,slaver;}
3.枚举类工具 set
public class DataSourceContextHolder {
private static final ThreadLocal<DataSourceEnum> CONTEXT_HOLDER = new ThreadLocal<DataSourceEnum>() { @Override
protected DataSourceEnum initialValue() {
return DataSourceEnum.master;
}
};
public static void setDataSourceType(DataSourceEnum type) {
CONTEXT_HOLDER.set(type);
}
public static DataSourceEnum getDataSourceType() {
return CONTEXT_HOLDER.get();
}
public static void resetDataSourceType() {
CONTEXT_HOLDER.set(DataSourceEnum.master);
}
}
4.自定义注解
@Retention(RetentionPolicy.RUNTIME) // 在运行时可见
@Target(ElementType.METHOD) // 注解可以用在方法上
public @interface DataSourceTypeAnno { //使用方式在service层方法上添加@DataSourceTypeAnno(DataSourceEnum.数据源枚举类型)用于指定所使用的数据源
DataSourceEnum value() default DataSourceEnum.master; }
5.aop拦截:这里使用asp的
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.springframework.core.annotation.Order;
import org.springframework.stereotype.Component; import java.lang.reflect.Method; @Component
@Aspect
@Order(-100)//为了保证可以拦截到
public class DataSourceAspect {
@Pointcut("execution(* com.yzy.*.*..*(..)) " + //这里扫描的切点包是主要是service层,根据service层方法的上边所说的的自定义注解,去判断所使用的数据源类型,并动态切换数据源
"&& @annotation(com.yzy.config.DataSourceTypeAnno)")
public void dataSourcePointcut() {
} @Around("dataSourcePointcut()")
public Object doAround(ProceedingJoinPoint pjp) {
MethodSignature methodSignature = (MethodSignature) pjp.getSignature();
Method method = methodSignature.getMethod();
DataSourceTypeAnno typeAnno = method.getAnnotation(DataSourceTypeAnno.class);
DataSourceEnum sourceEnum = typeAnno.value(); if (sourceEnum == DataSourceEnum.master) {
DataSourceContextHolder.setDataSourceType(DataSourceEnum.master);
} else if (sourceEnum == DataSourceEnum.slaver) {
DataSourceContextHolder.setDataSourceType(DataSourceEnum.slaver);
} Object result = null;
try {
result = pjp.proceed();
} catch (Throwable throwable) {
throwable.printStackTrace();
} finally {
DataSourceContextHolder.resetDataSourceType();
} return result;
}
}
6.继承 AbstractRoutingDataSource 类,实现对应数据源key的切换
package com.yzy.config; import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
public class DynamicDataSource extends AbstractRoutingDataSource {
protected Object determineCurrentLookupKey() {
return DataSourceContextHolder.getDataSourceType();
}
}
7.配置mybatisConfig=》数据源信息
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.jdbc.DataSourceBuilder;//org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;该包在springboot2.0被取代,目前网上的都是这个springboot1.5的包,所以会一直报错
import org.springframework.boot.context.properties.ConfigurationProperties;
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 javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map; @Configuration
@MapperScan(basePackages = "com.yzy.*.mapper")//扫描dao层mapper接口
public class MyBatisConfig { /**
* @return
* @throws Exception
* @Primary 必需指定一个且只能有一个主数据源,否则报错
*/
@Primary
@Bean("masterDataSource")
@ConfigurationProperties(prefix = "spring.datasource.userauth")//根据数据源前缀到application.yml读取数据源信息//此处改变前缀可以改变默认数据源//
public DataSource masterDataSource() throws Exception {
return DataSourceBuilder.create().build();
} @Bean("slaverDataSource")
@ConfigurationProperties(prefix = "spring.datasource.personnel")//根据数据源前缀到application.yml读取数据源信息//可以配置更多数据源,到前提是application.yml中存在,而且也需要在枚举类中添加枚举类型
public DataSource slaverDataSource() throws Exception {
return DataSourceBuilder.create().build();
} /**
* @Qualifier 根据名称进行注入,通常是在具有相同的多个类型的实例的一个注入(例如有多个DataSource类型的实例)
* @DataSourceTypeAnno(DataSourceEnum.master)事务方法需要指定数据源
*/
@Bean("dynamicDataSource")
public DynamicDataSource dynamicDataSource(@Qualifier("masterDataSource") DataSource masterDataSource,
@Qualifier("slaverDataSource") DataSource slaverDataSource) {
Map<Object, Object> targetDataSources = new HashMap<Object, Object>();
targetDataSources.put(DataSourceEnum.master, masterDataSource);
targetDataSources.put(DataSourceEnum.slaver, slaverDataSource); DynamicDataSource dataSource = new DynamicDataSource();
dataSource.setTargetDataSources(targetDataSources);// 该方法是AbstractRoutingDataSource的方法
dataSource.setDefaultTargetDataSource(masterDataSource);// 默认的datasource设置为myTestDbDataSource return dataSource;
} /**
* 根据数据源创建SqlSessionFactory
*/
@Bean
public SqlSessionFactory sqlSessionFactory(@Qualifier("dynamicDataSource") DynamicDataSource dynamicDataSource,
@Value("mybatis.type-aliases-package") String typeAliasesPackage) throws Exception {
SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
factoryBean.setDataSource(dynamicDataSource);// 指定数据源(这个必须有,否则报错)
// 下边两句仅仅用于*.xml文件,如果整个持久层操作不需要使用到xml文件的话(只用注解就可以搞定),则不加
factoryBean.setTypeAliasesPackage(typeAliasesPackage);// 指定实体类所在的包 factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapping/**/*Mapper.xml"));//扫描mapper.xml文件包
return factoryBean.getObject();
} /**
* 配置事务管理器
*/
@Bean
public DataSourceTransactionManager transactionManager(DynamicDataSource dataSource) throws Exception {
return new DataSourceTransactionManager(dataSource);
}
}