spring boot 中 Mybatis plus 多數據源的配置方法

最近在學習spring boot，發如今jar包依賴方面作不多的工做量就能夠了，對於數據庫操做，我用的比較多的是mybatis plus，在中央倉庫已經有mybatis-plus的插件了，對於單數據源來講直接使用就是了，但我本身的項目常常會有多數據源的狀況，本身去試着寫數據源的代碼，核心的方法參考mp說明文檔中多數據源的處理，使用動態數據源，根據需求去切換數據源

新建spring-boot項目

這一步你們去參考其它教程，很簡單

定義數據源相關Model

動態數據源

繼承了抽像的數據源，並實現了DataSource,歸根結底仍是數據就是了，在這裏面進行擴展，實現determiniCurrentlookupKey,也就是獲取當前須要使用數據源的key值，在父類方法中有一個map,用來保存key值與數據源的對應關係，而key值是與當前線程相關的，DbcontextHolder代碼見下

1. package com.zhangshuo.common.dataSource;
   import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;
   /**
   * Created by Administrator on 2017/5/31 0031.
   */
   publicclassDynamicDataSourceextendsAbstractRoutingDataSource{
   /**
   * 取得當前使用哪一個數據源
   *
   * @return
   */
   @Override
   protectedObject determineCurrentLookupKey(){
   returnDbContextHolder.getDbType();
   }
   }

    

定義DbContextHolder

裏面包含靜態方法，用來設置或獲取線程相關的數據源別名

1. publicclassDbContextHolder{
   privatestaticfinalThreadLocal<String> contextHolder =newThreadLocal<>();
   /**
   * 設置數據源
   *
   * @param dbTypeEnum
   */
   publicstaticvoid setDbType(DBTypeEnum dbTypeEnum){
   contextHolder.set(dbTypeEnum.getValue());
   }
   /**
   * 取得當前數據源
   *
   * @return
   */
   publicstaticString getDbType(){
   return contextHolder.get();
   }
   /**
   * 清除上下文數據
   */
   publicstaticvoid clearDbType(){
   contextHolder.remove();
   }
   }

    

定義數據源枚舉類

簡化設置線程相關數據源名稱的記憶壓力；直接從全部的數據源的枚舉中去選就能夠了~

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

    

生成 dataource 對象及 mp須要的對象

resources/application.properties的配置

在這裏定義的屬性名要與DruidDataSource和 SqlSessionFactory中須要的屬性相同，使用ConfigurationProperties註解來減小代碼

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=false
   
   
   
   mybatis-plus1:
   # 數據源名稱
     datasource: datasource1
     # mapper配置路徑
     mapperLocations:
       classpath:/mapper/test1/*.xml
     # mybatis配置路徑
     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 用戶輸入
       idType: 0
       # 靈據數類型
       dbType: mysql
       # 字段是否爲下劃線格式
       dbColumnUnderline: false
   
   datasource2:
     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-8
   
   mybatis-plus2:
   # 數據源名稱
     datasource: datasource2
     # mapper配置路徑
     mapperLocations:
       classpath:/mapper/test2/*.xml
     # mybatis配置路徑
     configLocation:
     # entity的包
     typeAliasesPackage: com.zhangshuo/test2/entity
     # 全局配置
     globalConfiguration:
       # id生成策略 0 自增 1 用戶輸入
       idType: 0
       # 靈據數類型
       dbType: mysql
       # 字段是否爲下劃線格式
       dbColumnUnderline: false

    

生成相應對象

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
   /**
   * 在方法上註解configurationProperties時，將會把屬性注入到返回結果的bean中
   */
   publicDruidDataSource dataSource1()throwsSQLException{
   returnnewDruidDataSource();
   }
   @ConfigurationProperties(prefix ="datasource2")
   @Bean(name ="datasource2")
   /**
   * 在方法上註解configurationProperties時，將會把屬性注入到返回結果的bean中
   */
   publicDruidDataSource dataSource2()throwsSQLException{
   returnnewDruidDataSource();
   }
   @Bean(name ="datasource")
   @Primary
   publicDynamicDataSource 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()
   @Primary
   publicMybatisSqlSessionFactoryBean 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;
   }
   }

    

設置AOP用來自動切換數據源

在這裏說明下個人目錄結構：
com.zhangshuo.test1.controller/service/mapper
com.zhangshuo.test2.controller/service/mapper

設置AOP

在dao層進行切換

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層進行切換
   */
   @Component
   @Aspect
   publicclassDataSourceInterceptor{
   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(){};
   /**
   * 切換數據源1
   */
   @Before("datasource1ServicePointcut()")
   publicvoid dataSource1Interceptor(){
   logger.debug("切換到數據源{}..............................","datasource1");
   DbContextHolder.setDbType(DBTypeEnum.datasource1);
   }
   /**
   * 切換數據源2
   */
   @Before("datasource2ServicePointcut()")
   publicvoid dataSource2Interceptor(){
   logger.debug("切換到數據源{}.......................","datasource2");
   DbContextHolder.setDbType(DBTypeEnum.datasource2);
   }
   }

    

到這裏就能夠進行測試了；
順帶貼下mybatis-plus的分頁插件，我是定義到了mybatis-config.xml中，也能夠手動在sqlSessionfacotry中的setPlugins中()定義；

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>