MyBatis多数据源的两种配置方式
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:
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
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