前言
同一个项目有时会涉及到多个数据库，也就是多数据源。多数据源又可以分为两种情况：
1）两个或多个数据库没有相关性，各自独立，其实这种可以作为两个项目来开发。比如在游戏开发中一个数据库是平台数据库，其它还有平台下的游戏对应的数据库；
2）两个或多个数据库是master-slave的关系，比如有mysql搭建一个 master-master，其后又带有多个slave；或者采用mha搭建的master-slave复制；
mybatis多数据源的配置主要有两种方式:
- 通过@mapperscan注解，对不同包下的mapper使用不同的sqlsessionfactory
- 通过@mapperscan注解加自定义注解，对使用不同注解的mapper使用不同的sqlsessionfactory
第二种配置相对灵活，示例如下:
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package bj;import ch.qos.logback.classic.level;import ch.qos.logback.classic.logger;import com.zaxxer.hikari.hikaridatasource;import io.shardingsphere.shardingjdbc.spring.boot.springbootconfiguration;import org.apache.ibatis.annotations.mapper;import org.apache.ibatis.annotations.select;import org.apache.ibatis.session.sqlsessionfactory;import org.mybatis.spring.sqlsessionfactorybean;import org.mybatis.spring.annotation.mapperscan;import org.slf4j.loggerfactory;import org.springframework.boot.springapplication;import org.springframework.boot.webapplicationtype;import org.springframework.boot.autoconfigure.springbootapplication;import org.springframework.boot.context.event.applicationreadyevent;import org.springframework.context.applicationlistener;import org.springframework.context.annotation.bean;import org.springframework.context.annotation.configuration;import org.springframework.context.annotation.primary;import org.springframework.jdbc.core.jdbctemplate;import javax.annotation.resource;import javax.sql.datasource;import java.lang.annotation.elementtype;import java.lang.annotation.retention;import java.lang.annotation.retentionpolicy;import java.lang.annotation.target;import java.util.list;import java.util.map;/** * created by baijifeilong@gmail.com at 2018/12/6 下午9:29 * <p> * mybatis多数据源演示 */@springbootapplication(exclude = {springbootconfiguration.class})@configuration@mapperscan(annotationclass = mapper.class, basepackageclasses = mybatisapp.class, sqlsessionfactoryref = "sqlsessionfactory")public class mybatisapp implements applicationlistener<applicationreadyevent> { /** * secondarymapper配置 * \@mapperscan 注解一次只能添加一个，所以需要单独再加一个配置类 * 自定义@mapperscan会替换mybatis自动添加的默认@mapperscan。所以主@mapperscan也必须显式添加 */ @configuration @mapperscan(annotationclass = secondarymapper.class, basepackageclasses = mybatisapp.class, sqlsessionfactoryref = "sqlsessionfactorysecond") static class secondarymapperconfiguration { } public static void main(string[] args) { new springapplication(mybatisapp.class) {{ setwebapplicationtype(webapplicationtype.none); }}.run(args); } @resource private datasource datasource; @resource private datasource datasourcesecond; @resource private jdbctemplate jdbctemplate; @resource private usermapper usermapper; @resource private secondaryusermapper secondaryusermapper; private void initlogger() { ((logger) loggerfactory.getlogger(mybatisapp.class)).setlevel(level.debug); ((logger) loggerfactory.getlogger(jdbctemplate.class)).setlevel(level.debug); } private void initdatabase() { string olddatabase = jdbctemplate.queryforobject("select database()", string.class); jdbctemplate.execute("drop schema if exists one"); jdbctemplate.execute("create schema one"); jdbctemplate.execute("use one"); jdbctemplate.execute("create table user(id int auto_increment primary key, name varchar(32) charset 'utf8')"); jdbctemplate.execute("insert into user(name) values ('人民的儿子')"); jdbctemplate.execute("insert into user(name) values ('人民的孙子')"); jdbctemplate.execute("insert into user(name) values ('人民的曾孙子')"); jdbctemplate.execute("drop schema if exists two"); jdbctemplate.execute("create schema two"); jdbctemplate.execute("use two"); jdbctemplate.execute("create table user(id int auto_increment primary key, name varchar(32) charset 'utf8')"); jdbctemplate.execute("insert into user(name) values ('人民的爹')"); jdbctemplate.execute("insert into user(name) values ('人民的爷')"); jdbctemplate.execute("insert into user(name) values ('人民的太爷')"); jdbctemplate.execute("insert into user(name) values ('人民的老太爷')"); jdbctemplate.execute("use " + olddatabase); } @override public void onapplicationevent(applicationreadyevent applicationreadyevent) { initlogger(); initdatabase(); system.out.println("users:"); usermapper.selectall().foreach(system.out::println); system.out.println("secondary users:"); secondaryusermapper.selectall().foreach(system.out::println); } /** * 主数据源 * <p> * 如果不添加@primary注解, mybatis可以工作，但是jdbctemplate无法注入 * * @return . */ @primary @bean public datasource datasource() { return new hikaridatasource() {{ setjdbcurl("jdbc:mysql://localhost/one?useunicode=true&characterencoding=utf8"); setusername("root"); setpassword("root"); }}; } /** * 副数据源 * * @return . */ @bean public datasource datasourcesecond() { return new hikaridatasource() {{ setjdbcurl("jdbc:mysql://localhost/two?useunicode=true&characterencoding=utf8"); setusername("root"); setpassword("root"); }}; } /** * 主sqlsessionfactory。使用主数据源。自定义sqlsessionfactory后，mybatis就不自动添加sqlsessionfactory了，所以必须有 * * @return . * @throws exception . */ @bean public sqlsessionfactory sqlsessionfactory() throws exception { return new sqlsessionfactorybean() {{ setdatasource(datasource); }}.getobject(); } /** * 副sqlsessionfactory。使用副数据源 * * @return . * @throws exception . */ @bean public sqlsessionfactory sqlsessionfactorysecond() throws exception { return new sqlsessionfactorybean() {{ setdatasource(datasourcesecond); }}.getobject(); } @mapper interface usermapper { @select("select * from user") list<map<string, object>> selectall(); } @secondarymapper interface secondaryusermapper { @select("select * from user") list<map<string, object>> selectall(); } /** * 自定义mapper注解，用于标识使用的数据源 */ @target(elementtype.type) @retention(retentionpolicy.runtime) @interface secondarymapper { }} |
控制台输出:
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: spring boot :: (v2.1.0.release)2018-12-07 11:49:02.596 info 5154 --- [ main] bj.mybatisapp : starting mybatisapp on macbook-air-2.local with pid 5154 (/users/yuchao/temp/java/hellomaven/target/classes started by yuchao in /users/yuchao/temp/java/hellomaven)
2018-12-07 11:49:02.633 info 5154 --- [ main] bj.mybatisapp : no active profile set, falling back to default profiles: default
2018-12-07 11:49:05.341 info 5154 --- [ main] com.zaxxer.hikari.hikaridatasource : hikaripool-1 - starting...
2018-12-07 11:49:05.499 info 5154 --- [ main] com.zaxxer.hikari.hikaridatasource : hikaripool-1 - start completed.
2018-12-07 11:49:05.547 info 5154 --- [ main] org.quartz.impl.stdschedulerfactory : using default implementation for threadexecutor
2018-12-07 11:49:05.569 info 5154 --- [ main] org.quartz.core.schedulersignalerimpl : initialized scheduler signaller of type: class org.quartz.core.schedulersignalerimpl
2018-12-07 11:49:05.569 info 5154 --- [ main] org.quartz.core.quartzscheduler : quartz scheduler v.2.3.0 created.
2018-12-07 11:49:05.570 info 5154 --- [ main] org.quartz.simpl.ramjobstore : ramjobstore initialized.
2018-12-07 11:49:05.571 info 5154 --- [ main] org.quartz.core.quartzscheduler : scheduler meta-data: quartz scheduler (v2.3.0) 'quartzscheduler' with instanceid 'non_clustered'
scheduler class: 'org.quartz.core.quartzscheduler' - running locally.
not started.
currently in standby mode.
number of jobs executed: 0
using thread pool 'org.quartz.simpl.simplethreadpool' - with 10 threads.
using job-store 'org.quartz.simpl.ramjobstore' - which does not support persistence. and is not clustered.2018-12-07 11:49:05.571 info 5154 --- [ main] org.quartz.impl.stdschedulerfactory : quartz scheduler 'quartzscheduler' initialized from an externally provided properties instance.
2018-12-07 11:49:05.571 info 5154 --- [ main] org.quartz.impl.stdschedulerfactory : quartz scheduler version: 2.3.0
2018-12-07 11:49:05.571 info 5154 --- [ main] org.quartz.core.quartzscheduler : jobfactory set to: org.springframework.scheduling.quartz.springbeanjobfactory@769a58e5
2018-12-07 11:49:05.780 warn 5154 --- [ main] reactor.netty.tcp.tcpresources : [http] resources will use the default loopresources: defaultloopresources {prefix=reactor-http, daemon=true, selectcount=4, workercount=4}
2018-12-07 11:49:05.780 warn 5154 --- [ main] reactor.netty.tcp.tcpresources : [http] resources will use the default connectionprovider: pooledconnectionprovider {name=http, poolfactory=reactor.netty.resources.connectionprovider$$lambda$284/1788545647@10667848}
2018-12-07 11:49:06.061 info 5154 --- [ main] o.s.s.quartz.schedulerfactorybean : starting quartz scheduler now
2018-12-07 11:49:06.062 info 5154 --- [ main] org.quartz.core.quartzscheduler : scheduler quartzscheduler_$_non_clustered started.
2018-12-07 11:49:06.079 info 5154 --- [ main] bj.mybatisapp : started mybatisapp in 4.645 seconds (jvm running for 6.354)
2018-12-07 11:49:06.084 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql query [select database()]
2018-12-07 11:49:06.105 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [drop schema if exists one]
2018-12-07 11:49:06.115 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [create schema one]
2018-12-07 11:49:06.117 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [use one]
2018-12-07 11:49:06.119 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [create table user(id int auto_increment primary key, name varchar(32) charset 'utf8')]
2018-12-07 11:49:06.153 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的儿子')]
2018-12-07 11:49:06.157 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的孙子')]
2018-12-07 11:49:06.161 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的曾孙子')]
2018-12-07 11:49:06.164 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [drop schema if exists two]
2018-12-07 11:49:06.174 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [create schema two]
2018-12-07 11:49:06.176 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [use two]
2018-12-07 11:49:06.178 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [create table user(id int auto_increment primary key, name varchar(32) charset 'utf8')]
2018-12-07 11:49:06.226 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的爹')]
2018-12-07 11:49:06.231 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的爷')]
2018-12-07 11:49:06.235 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的太爷')]
2018-12-07 11:49:06.243 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [insert into user(name) values ('人民的老太爷')]
2018-12-07 11:49:06.246 debug 5154 --- [ main] o.s.jdbc.core.jdbctemplate : executing sql statement [use one]
users:
2018-12-07 11:49:06.271 debug 5154 --- [ main] bj.mybatisapp$usermapper.selectall : ==> preparing: select * from user
2018-12-07 11:49:06.297 debug 5154 --- [ main] bj.mybatisapp$usermapper.selectall : ==> parameters:
2018-12-07 11:49:06.314 debug 5154 --- [ main] bj.mybatisapp$usermapper.selectall : <== total: 3
{name=人民的儿子, id=1}
{name=人民的孙子, id=2}
{name=人民的曾孙子, id=3}
secondary users:
2018-12-07 11:49:06.318 info 5154 --- [ main] com.zaxxer.hikari.hikaridatasource : hikaripool-2 - starting...
2018-12-07 11:49:06.324 info 5154 --- [ main] com.zaxxer.hikari.hikaridatasource : hikaripool-2 - start completed.
2018-12-07 11:49:06.325 debug 5154 --- [ main] b.m.selectall : ==> preparing: select * from user
2018-12-07 11:49:06.325 debug 5154 --- [ main] b.m.selectall : ==> parameters:
2018-12-07 11:49:06.328 debug 5154 --- [ main] b.m.selectall : <== total: 4
{name=人民的爹, id=1}
{name=人民的爷, id=2}
{name=人民的太爷, id=3}
{name=人民的老太爷, id=4}
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对服务器之家的支持。
原文链接：https://baijifeilong.github.io/2018/12/07/mybatis-multiple-datasource/
