spring boot 中 Mybatis plus 多数据源的配置方法

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*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
    */
    @Override
    protectedObject 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=false mybatis-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: 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:
    # 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")
    @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;
    }
    }

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
    @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>
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