springboot + mybatis + druid + 多数据源

一. 简介

           俩个数据库db1,db2， db1数据库的mapper.xml和db2数据库的mapper.xml分别放到不同的目录下, 通过给不同的目录配置不同的数据源，并分别监控各自的事务。

二. sql脚本

           db1数据库的user表：

CREATE TABLE `user` (
  `id` int(11) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

           db2数据库的role表：

CREATE TABLE `role` (
  `id` int(11) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

三. 工程搭建

3.1 目录结构图

3.2 pom.xml文件

    4.0.0

    com.example
    datasources
    0.0.1-SNAPSHOT
    jar

    datasources
    Demo project for Spring Boot

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.4.RELEASE
        
    

    
        UTF-8
        UTF-8
        1.8
    

    

        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            1.3.2
        

        
            mysql
            mysql-connector-java
            runtime
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
            org.apache.commons
            commons-lang3
            3.4
        

        
            com.fasterxml.jackson.core
            jackson-core
        
        
            com.fasterxml.jackson.core
            jackson-databind
        
        
            com.fasterxml.jackson.datatype
            jackson-datatype-joda
        
        
            com.fasterxml.jackson.module
            jackson-module-parameter-names
        
        
            org.springframework.boot
            spring-boot-starter-aop
        

        
        
            com.github.pagehelper
            pagehelper-spring-boot-starter
            1.2.5
        

        
        
            com.alibaba
            druid-spring-boot-starter
            1.1.9
        

        
            org.springframework.boot
            spring-boot-starter-thymeleaf
        

        
            org.springframework.boot
            spring-boot-starter-jdbc
        

        
        
            org.springframework.boot
            spring-boot-starter-jta-atomikos
        

        
        
            io.springfox
            springfox-swagger2
            2.6.1
        
        
            io.springfox
            springfox-swagger-ui
            2.6.1
        
        


    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

3.3 application.yml

server:
  port: 8080


spring:
  datasource:
    db1:
      driverClassName: com.mysql.jdbc.Driver
      username: 用户名
      password: 密码
      # spring2.0此处为jdbc-url
      jdbc-url: jdbc:mysql://IP:3306/db1?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
      type: com.alibaba.druid.pool.DruidDataSource
    db2:
      driverClassName: com.mysql.jdbc.Driver
      username: 用户名
      password: 密码
      # spring2.0此处为jdbc-url
      jdbc-url: jdbc:mysql://IP:3306/db2?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true
      type: com.alibaba.druid.pool.DruidDataSource

 3.4 数据源配置类

3.4.1 db1数据库的数据源 （主数据源@Primary）

package com.example.datasources.datasource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.example.datasources.mapper.db1", sqlSessionTemplateRef = "db1SqlSessionTemplate")
public class DataSource1Config {

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    @Primary
    public DataSource db1DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public SqlSessionFactory db1SqlSessionFactory(@Qualifier("db1DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:com/example/datasources/mapper/db1/*.xml"));
        return bean.getObject();
    }

    @Bean
    @Primary
    public DataSourceTransactionManager db1TransactionManager(@Qualifier("db1DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    @Primary
    public SqlSessionTemplate db1SqlSessionTemplate(@Qualifier("db1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

}

3.4.2 db2数据库的数据源

package com.example.datasources.datasource;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.SqlSessionTemplate;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.jdbc.DataSourceBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.example.datasources.mapper.db2", sqlSessionTemplateRef = "db2SqlSessionTemplate")
public class DataSource2Config {

    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource db2DataSource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public SqlSessionFactory db2SqlSessionFactory(@Qualifier("db2DataSource") DataSource dataSource) throws Exception {
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();
        bean.setDataSource(dataSource);
        bean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:com/example/datasources/mapper/db2/*.xml"));
        return bean.getObject();
    }

    @Bean
    public DataSourceTransactionManager db2TransactionManager(@Qualifier("db2DataSource") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }

    @Bean
    public SqlSessionTemplate db2SqlSessionTemplate(@Qualifier("db2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception {
        return new SqlSessionTemplate(sqlSessionFactory);
    }


}

3.5 Controller

3.5.1 db1的UserController

package com.example.datasources.controller;

import com.example.datasources.entity.db1.User;
import com.example.datasources.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/select/list")
    public List selectUserList() {
        return this.userService.selectUserList();
    }

    @GetMapping("/save")
    public void saveUser(User user) {
        this.userService.saveUser(user);
    }


}

3.5.2 db2的RoleController

package com.example.datasources.controller;

import com.example.datasources.entity.db2.Role;
import com.example.datasources.service.RoleService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/role")
public class RoleController {

    @Autowired
    private RoleService roleService;

    @GetMapping("/select/list")
    public List selectRoleList() {
        return this.roleService.selectRoleList();
    }

    @GetMapping("/save")
    public void saveRole(Role role) {
        this.roleService.saveRole(role);
    }


}

3.6 Service

3.6.1 db1的UserService

package com.example.datasources.service;

import com.example.datasources.entity.db1.User;

import java.util.List;

public interface UserService {

    List selectUserList();

    void saveUser(User user);

}

3.6.2 db2的RoleService

package com.example.datasources.service;

import com.example.datasources.entity.db2.Role;

import java.util.List;

public interface RoleService {

    List selectRoleList();

    void saveRole(Role role);

}

3.7 serviceImpl

3.7.1 db1的UserServiceImpl

package com.example.datasources.service.impl;

import com.example.datasources.entity.db1.User;
import com.example.datasources.mapper.db1.UserMapper;
import com.example.datasources.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public List selectUserList() {
        return this.userMapper.selectUserList();
    }

    @Transactional
    @Override
    public void saveUser(User user) {
        this.userMapper.saveUser(user);
//        throw new RuntimeException();
    }
}

3.7.2 db2的RoleServiceImpl

package com.example.datasources.service.impl;

import com.example.datasources.entity.db2.Role;
import com.example.datasources.mapper.db2.RoleMapper;
import com.example.datasources.service.RoleService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
public class RoleServiceImpl implements RoleService {

    @Autowired
    private RoleMapper roleMapper;

    @Override
    public List selectRoleList() {
        return this.roleMapper.selectRoleList();
    }

    // 注：不是主数据源必须要声明其数据源，否则事务不起作用
    @Transactional(value = "db2TransactionManager")
    @Override
    public void saveRole(Role role) {
        this.roleMapper.saveRole(role);
//        throw new RuntimeException();
    }
}

3.8 mapper

3.8.1 db1的UserMapper

package com.example.datasources.mapper.db1;

import com.example.datasources.entity.db1.User;

import java.util.List;

public interface UserMapper {

    List selectUserList();

    void saveUser(User user);

}

3.8.2 db2的RoleMapper

package com.example.datasources.mapper.db2;

import com.example.datasources.entity.db2.Role;

import java.util.List;

public interface RoleMapper {

    List selectRoleList();

    void saveRole(Role role);
}

3.9 mapper.xml

3.9.1 db1的UserMapper.xml

    
        
        
    


    
        id, `name`
    


    
        SELECT
          
        FROM `user`
    


    
        INSERT INTO `user`
           (id, `name`)
        VALUES
           ( #{id}, #{name} )
    

3.9.2 db2的RoleMapper.xml

    
        
        
    

    
        id, name
    

    
        SELECT
          
        FROM
          role
    


    
        INSERT INTO `role`
           (id, `name`)
        VALUES
           ( #{id}, #{name} )
    

3.10 entity

3.10.1 db1的User

package com.example.datasources.entity.db1;

public class User {

    private Integer id;
    private String name;

    public User() {
    }

    public User(Integer id, String name) {
        this.id = id;
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

3.10.2 db2的Role 

package com.example.datasources.entity.db2;

public class Role {

    private Integer id;
    private String name;

    public Role() {
    }

    public Role(Integer id, String name) {
        this.id = id;
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

}

3.11  启动类

package com.example.datasources;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DatasourcesApplication {

    public static void main(String[] args) {
        SpringApplication.run(DatasourcesApplication.class, args);
    }
}

四. 测试

            可以直接在浏览器测试，测试事务的时候可以将异常打开。

            需要注意的是： 非主数据源必须要在@Transactional注解中指定数据源，否则事务不起作用。主数据库不需要。