spring boot+gradle+mybatis多数据源配置

目录

  • 场景
  • 多数据源存在问题
  • demo演示流程
  • 代码结构
  • 引入jar包
  • 配置application.properties
  • 数据源初始化配置
  • mybatis生成对应的entity、mapper、和xml文件
  • 完成对应的service
  • 测试多数据源事务问题

1. 场景:

经常会碰到这种应用场景,比如说下订单的操作,有需要修改订单库中信息,又需要修改产品库中库存,这一个操作就是需要一次性操作两个数据源的情况。

2. 多数据源存在问题

事务问题

3. demo演示流程

  1. 引入jar包
  2. 配置application.properties
  3. 数据源初始化配置
  4. mybatis生成对应的entity、mapper、和xml文件
  5. 完成对应的service
  6. 测试多数据源事务问题

4. 代码结构

spring boot+gradle+mybatis多数据源配置_第1张图片

5. 引入jar包(build.gradle)

spring boot版本使用2.0.6.RELEASE

implementation('org.mybatis.spring.boot:mybatis-spring-boot-starter:1.3.2')
runtimeOnly('mysql:mysql-connector-java')
testImplementation('org.springframework.boot:spring-boot-starter-test')
compile 'tk.mybatis:mapper-spring-boot-starter:1.1.5'

6. 配置application.properties

first.datasource.jdbc-url=jdbc:mysql://ip:3306/test1?useSSL=false&useUnicode=true&characterEncoding=utf-8
first.datasource.username=root
first.datasource.password=**
first.datasource.driver-class-name=com.mysql.jdbc.Driver

second.datasource.jdbc-url=jdbc:mysql://ip:3306/test2?useSSL=false&useUnicode=true&characterEncoding=utf-8
second.datasource.username=root
second.datasource.password=***
second.datasource.driver-class-name=com.mysql.jdbc.Driver

7. 数据源初始化配置

  1. application取消默认数据源的初始化
  2. 数据源初始化
  3. 不同数据源对应不同的mapper

7.1 application取消默认数据源的初始化

SpringBootApplication 注解中后面添加exclude = {DataSourceAutoConfiguration.class})

@SpringBootApplication(exclude = {
		DataSourceAutoConfiguration.class
})
public class TwodatasourceApplication {

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

7.2 数据源初始化

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 javax.sql.DataSource;

/**
 * @program: twodatasource
 * @description: 数据源
 * @author: chengqj
 * @create: 2018-10-24 11:39
 **/
@Configuration
public class DataSourceConfig {

    @Bean(name = "ds1")
     // application.properteis中对应属性的前缀
    @ConfigurationProperties(prefix = "first.datasource")
    public DataSource dataSource1() {
        return DataSourceBuilder.create().build();
    }

    @Bean(name = "ds2")
    // application.properteis中对应属性的前缀
    @ConfigurationProperties(prefix = "second.datasource") 
    public DataSource dataSource2() {
        return DataSourceBuilder.create().build();
    }
}

7.3 数据源初始化配置

数据源first

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.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

/**
 * @program: twodatasource
 * @description: 数据库A配置
 * @author: chengqj
 * @create: 2018-10-24 11:40
 **/
@Configuration
//配置对应扫描的mapper路径
@MapperScan(basePackages = {"com.chengqj.twodatasource.dao.mapper"}, sqlSessionFactoryRef = "sqlSessionFactory1")
public class MybatisDbAConfig {

    @Autowired
    @Qualifier("ds1")
    private DataSource ds1;

    @Bean
    public SqlSessionFactory sqlSessionFactory1() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        // 使用first数据源, 连接first库
        factoryBean.setDataSource(ds1); 
        return factoryBean.getObject();
    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplate1() throws Exception {
         // 使用上面配置的Factory
        SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory1()); 
        return template;
    }
}

数据源second

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.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

/**
 * @program: twodatasource
 * @description: 数据源B
 * @author: chengqj
 * @create: 2018-10-24 11:42
 **/
@Configuration
@MapperScan(basePackages = {"com.chengqj.twodatasource.dao.mapper2"}, sqlSessionFactoryRef = "sqlSessionFactory2")
public class MybatisDbBConfig {
    @Autowired
    @Qualifier("ds2")
    private DataSource ds2;
    
    @Bean
    public SqlSessionFactory sqlSessionFactory2() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(ds2);
        return factoryBean.getObject();
    }
    
    @Bean
    public SqlSessionTemplate sqlSessionTemplate2() throws Exception {
        SqlSessionTemplate template = new SqlSessionTemplate(sqlSessionFactory2());
        return template;
    }
}

8. mybatis生成对应的entity、mapper、和xml文件

entity TClass和Teacher
Teacher

import javax.persistence.*;

@Table(name = "t_teacher")
public class Teacher {
    /**
     * 班主任id
     */
    @Id
    private String id;

    /**
     * 姓名
     */
    private String name;

    /**
     * 获取班主任id
     *
     * @return id - 班主任id
     */
    public String getId() {
        return id;
    }

    /**
     * 设置班主任id
     *
     * @param id 班主任id
     */
    public void setId(String id) {
        this.id = id == null ? null : id.trim();
    }

    /**
     * 获取姓名
     *
     * @return name - 姓名
     */
    public String getName() {
        return name;
    }

    /**
     * 设置姓名
     *
     * @param name 姓名
     */
    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }
}

TClass

import javax.persistence.*;

@Table(name = "t_class")
public class TClass {
    /**
     * 班级表主键
     */
    @Id
    private String id;

    /**
     * 班级名称
     */
    private String name;

    /**
     * 获取班级表主键
     *
     * @return id - 班级表主键
     */
    public String getId() {
        return id;
    }

    /**
     * 设置班级表主键
     *
     * @param id 班级表主键
     */
    public void setId(String id) {
        this.id = id == null ? null : id.trim();
    }

    /**
     * 获取班级名称
     *
     * @return name - 班级名称
     */
    public String getName() {
        return name;
    }

    /**
     * 设置班级名称
     *
     * @param name 班级名称
     */
    public void setName(String name) {
        this.name = name == null ? null : name.trim();
    }
}

mapper
TClassMapper

import com.chengqj.twodatasource.dao.entity.TClass;
import tk.mybatis.mapper.common.Mapper;

public interface TClassMapper extends Mapper<TClass> {
}

TeacherMapper

import com.chengqj.twodatasource.dao.entity.Teacher;
import tk.mybatis.mapper.common.Mapper;

public interface TeacherMapper extends Mapper<Teacher> {
}

xml文件
TClassMapper.xml



<mapper namespace="com.chengqj.twodatasource.dao.mapper.TClassMapper">
  <resultMap id="BaseResultMap" type="com.chengqj.twodatasource.dao.entity.TClass">
    
    <id column="id" jdbcType="VARCHAR" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
  resultMap>
mapper>

TeacherMapper.xml



<mapper namespace="com.chengqj.twodatasource.dao.mapper2.TeacherMapper">
  <resultMap id="BaseResultMap" type="com.chengqj.twodatasource.dao.entity.Teacher">
    
    <id column="id" jdbcType="VARCHAR" property="id" />
    <result column="name" jdbcType="VARCHAR" property="name" />
  resultMap>
mapper>

9. 完成对应的service

TClassServiceImpl

import com.chengqj.twodatasource.dao.entity.TClass;
import com.chengqj.twodatasource.dao.mapper.TClassMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @program: twodatasource
 * @description: class服务类
 * @author: chengqj
 * @create: 2018-10-25 10:06
 **/
@Service
public class TClassServiceImpl {
    @Autowired
    private TClassMapper tclassMapper;

    public void save(TClass tclass){
        tclassMapper.insert(tclass);
    }
}

TeacherServiceImpl

import com.chengqj.twodatasource.dao.entity.Teacher;
import com.chengqj.twodatasource.dao.mapper2.TeacherMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @program: twodatasource
 * @description: teacher服务类
 * @author: chengqj
 * @create: 2018-10-25 10:08
 **/
@Service
public class TeacherServiceImpl {
    @Autowired
    private TeacherMapper teacherMapper;

    public void save(Teacher teacher) {
        teacherMapper.insert(teacher);
    }
}

10. 多数据源事务问题

JtaTestServiceImpl

import com.chengqj.twodatasource.dao.entity.TClass;
import com.chengqj.twodatasource.dao.entity.Teacher;
import com.chengqj.twodatasource.service.TClassServiceImpl;
import com.chengqj.twodatasource.service2.TeacherServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

import java.util.LinkedHashMap;
import java.util.Map;

@Service
public class JtaTestServiceImpl{

    @Autowired
    private TeacherServiceImpl teacherService;
    @Autowired
    private TClassServiceImpl tclassService;

    @Transactional( propagation = Propagation.REQUIRED, rollbackFor = { RuntimeException.class })
    public Map<String, Object> test01() {
        LinkedHashMap<String,Object> resultMap=new LinkedHashMap<String,Object>();
        TClass tClass=new TClass();
        tClass.setId("21");
        tClass.setName("8888");
        tclassService.save(tClass);

        Teacher teacher=new Teacher();
        teacher.setId("21");
        teacher.setName("8888");
        teacherService.save(teacher);
        //执行出错
        System.out.println(1/0);
        resultMap.put("state","success");
        resultMap.put("message","分布式事务问题");
        return resultMap;
    }
}

虽然service配置了异常回滚,但是因为是多数据库的情况,事务问题无法回滚,该问题可以使用atomikos框架进行解决。


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