spring boot 中 Mybatis plus 多数据源的配置

最近在学习spring boot，发现在jar包依赖方面做很少的工作量就可以了，对于数据库操作，我用的比较多的是mybatis plus，在中央仓库已经有mybatis-plus的插件了，对于单数据源来说直接使用就是了，但我自己的项目经常会有多数据源的情况，自己去试着写数据源的代码，核心的方法参考mp说明文档中多数据源的处理，使用动态数据源，根据需求去切换数据源

新建spring-boot项目

这一步大家去参考其它教程，很简单

定义数据源相关Model

动态数据源

继承了抽像的数据源，并实现了DataSource,归根结底还是数据就是了，在这里面进行扩展，实现determiniCurrentlookupKey,也就是获取当前需要使用数据源的key值，在父类方法中有一个map,用来保存key值与数据源的对应关系，而key值是与当前线程相关的，DbcontextHolder代码见下

1. package com.zhangshuo.common.dataSource;import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;/*** Created by Administrator on 2017/5/31 0031.*/publicclassDynamicDataSourceextendsAbstractRoutingDataSource{/*** 取得当前使用哪个数据源** @return*/@OverrideprotectedObject determineCurrentLookupKey(){returnDbContextHolder.getDbType();}}

    

定义DbContextHolder

里面包含静态方法，用来设置或获取线程相关的数据源别名

1. publicclassDbContextHolder{privatestaticfinalThreadLocal<String> contextHolder =newThreadLocal<>();/*** 设置数据源** @param dbTypeEnum*/publicstaticvoid setDbType(DBTypeEnum dbTypeEnum){contextHolder.set(dbTypeEnum.getValue());}/*** 取得当前数据源** @return*/publicstaticString getDbType(){return contextHolder.get();}/*** 清除上下文数据*/publicstaticvoid clearDbType(){contextHolder.remove();}}

    

定义数据源枚举类

简化设置线程相关数据源名称的记忆压力；直接从所有的数据源的枚举中去选就可以了~

1. publicenumDBTypeEnum{datasource1("datasource1"), datasource2("datasource2");privateString value;DBTypeEnum(String value){this.value = value;}publicString getValue(){return value;}}

    

生成 dataource 对象及 mp需要的对象

resources/application.properties的配置

在这里定义的属性名要与DruidDataSource和 SqlSessionFactory中需要的属性相同，使用ConfigurationProperties注解来减少代码

1. datasource1:  username: root  password: 123456  filters: mergeStat,wall,logback  initialSize: 5  maxActive: 50  minIdle: 5  maxWait: 6000  validationQuery: SELECT 'x'  testOnBorrow: true  testOnReturn: true  testWhileIdle: true  timeBetweenEvictionRunsMillis: 60000  minEvictableIdleTimeMillis: 300000  removeAbandoned: true  removeAbandonedTimeout: 1800  logAbandoned: true  url: jdbc:mysql://192.168.168.118:3306/test?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull&transformedBitIsBoolean=true&useSSL=falsemybatis-plus1:# 数据源名称  datasource: datasource1  # mapper配置路径  mapperLocations:    classpath:/mapper/test1/*.xml  # mybatis配置路径  configLocation: classpath:/mybatis-config.xml  # entity的包  typeAliasesPackage: com.zhangshuo/test1/entity  # 全局配置  globalConfiguration:    # id生成策略 0 自增 1 用户输入    idType: 0    # 灵据数类型    dbType: mysql    # 字段是否为下划线格式    dbColumnUnderline: falsedatasource2:  username: root  password: 123456  filters: mergeStat,wall,logback  initialSize: 5  maxActive: 50  minIdle: 5  maxWait: 6000  validationQuery: SELECT 'x'  testOnBorrow: true  testOnReturn: true  testWhileIdle: true  timeBetweenEvictionRunsMillis: 60000  minEvictableIdleTimeMillis: 300000  removeAbandoned: true  removeAbandonedTimeout: 1800  logAbandoned: true  url: jdbc:mysql://192.168.168.118:3306/sms?useUnicode=true&characterEncoding=utf-8mybatis-plus2:# 数据源名称  datasource: datasource2  # mapper配置路径  mapperLocations:    classpath:/mapper/test2/*.xml  # mybatis配置路径  configLocation:  # entity的包  typeAliasesPackage: com.zhangshuo/test2/entity  # 全局配置  globalConfiguration:    # id生成策略 0 自增 1 用户输入    idType: 0    # 灵据数类型    dbType: mysql    # 字段是否为下划线格式    dbColumnUnderline: false

    

生成相应对象

1. import com.alibaba.druid.pool.DruidDataSource;import com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean;import com.zhangshuo.common.dataSource.DynamicDataSource;import org.mybatis.spring.annotation.MapperScan;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.boot.context.properties.ConfigurationProperties;import org.springframework.boot.context.properties.ConfigurationPropertiesBinding;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import org.springframework.context.annotation.Primary;import javax.sql.DataSource;import java.util.Map;import java.sql.SQLException;import java.util.HashMap;/*** Created by Administrator on 2017/5/31 0031.*/@Configuration@MapperScan(value ={"com.zhangshuo.test1.mapper","com.zhangshuo.test2.mapper"})publicclassDataSourceConfig{@ConfigurationProperties(prefix ="datasource1")@Bean(name ="datasource1")// @Primary/*** 在方法上注解configurationProperties时，将会把属性注入到返回结果的bean中*/publicDruidDataSource dataSource1()throwsSQLException{returnnewDruidDataSource();}@ConfigurationProperties(prefix ="datasource2")@Bean(name ="datasource2")/*** 在方法上注解configurationProperties时，将会把属性注入到返回结果的bean中*/publicDruidDataSource dataSource2()throwsSQLException{returnnewDruidDataSource();}@Bean(name ="datasource")@PrimarypublicDynamicDataSource dynamicDataSource(@Qualifier(value ="datasource1")DataSource dataSource1,@Qualifier(value ="datasource2")DataSource dataSource2){DynamicDataSource bean =newDynamicDataSource();Map<Object,Object> targetDataSources =newHashMap<>();targetDataSources.put("datasource1",dataSource1);targetDataSources.put("datasource2", dataSource2);bean.setTargetDataSources(targetDataSources);bean.setDefaultTargetDataSource(dataSource1);return bean;}@Bean(name ="sessionFactory1")@ConfigurationProperties(prefix ="mybatis-plus1")@ConfigurationPropertiesBinding()@PrimarypublicMybatisSqlSessionFactoryBean sqlSessionFactory1(@Qualifier(value ="datasource")DataSource dataSource){MybatisSqlSessionFactoryBean bean =newMybatisSqlSessionFactoryBean();bean.setDataSource(dataSource);return bean;}@Bean(name ="sessionFactory2")@ConfigurationProperties(prefix ="mybatis-plus2")@ConfigurationPropertiesBinding()publicMybatisSqlSessionFactoryBean sqlSessionFactory2(@Qualifier(value ="datasource")DataSource dataSource){MybatisSqlSessionFactoryBean bean =newMybatisSqlSessionFactoryBean();bean.setDataSource(dataSource);return bean;}}

    

设置AOP用来自动切换数据源

在这里说明下我的目录结构： 
com.zhangshuo.test1.controller/service/mapper 
com.zhangshuo.test2.controller/service/mapper

设置AOP

在dao层进行切换

1. import com.zhangshuo.common.dataSource.DBTypeEnum;import com.zhangshuo.common.dataSource.DbContextHolder;import org.aspectj.lang.annotation.Aspect;import org.aspectj.lang.annotation.Before;import org.aspectj.lang.annotation.Pointcut;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.stereotype.Component;/*** Created by Administrator on 2017/5/31 0031.* 以dao层进行切换*/@Component@AspectpublicclassDataSourceInterceptor{Logger logger =LoggerFactory.getLogger(DataSourceInterceptor.class);@Pointcut(value ="execution(public * com.zhangshuo.test1.mapper.**.*(..))")privatevoid datasource1ServicePointcut(){};@Pointcut(value ="execution(public * com.zhangshuo.test2.mapper.**.*(..))")privatevoid datasource2ServicePointcut(){};/*** 切换数据源1*/@Before("datasource1ServicePointcut()")publicvoid dataSource1Interceptor(){logger.debug("切换到数据源{}..............................","datasource1");DbContextHolder.setDbType(DBTypeEnum.datasource1);}/*** 切换数据源2*/@Before("datasource2ServicePointcut()")publicvoid dataSource2Interceptor(){logger.debug("切换到数据源{}.......................","datasource2");DbContextHolder.setDbType(DBTypeEnum.datasource2);}}

    

到这里就可以进行测试了； 
顺带贴下mybatis-plus的分页插件，我是定义到了mybatis-config.xml中，也可以手动在sqlSessionfacotry中的setPlugins中()定义；

1. <?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configuration        PUBLIC "-//ibatis.apache.org//DTD Config 3.0//EN"        "http://ibatis.apache.org/dtd/ibatis-3-config.dtd"><configuration>    <settings>        <setting name="cacheEnabled" value="false"/>        <setting name="lazyLoadingEnabled" value="false"/>        <setting name="aggressiveLazyLoading" value="true"/>        <setting name="logImpl" value="slf4j"/>    </settings>    <plugins>        <plugin interceptor="com.baomidou.mybatisplus.plugins.PaginationInterceptor">            <property name="dialectType" value="mysql" />            <property name="optimizeType" value="aliDruid" />        </plugin>    </plugins></configuration>