背景

这几天搞了个saas项目，里面用到了多数据和execl模板导出功能，
其实我是经常用到的，但没在博客中写过，最近有点时间，正好稍微写一下。 方便大家使用
这次我先写多数据，execl模板导出下次有空在写。

使用

pom引入

     <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>4.3.0</version>
        </dependency>
        

这里因为需要用的多个数据库 所以我又引入了mysql和postgresql，大家居然自己的情况来。
mysql版本我使用的是8.0.16
druid版本我使用的是1.1.20

 <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>${druid.version}</version>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
        </dependency>

配置文件

spring.datasource.druid.initial-size=5
spring.datasource.druid.max-active=20
spring.datasource.druid.min-idle=5
spring.datasource.druid.stat-view-servlet.reset-enable=true
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.dynamic.primary=master
spring.datasource.dynamic.strict=false
spring.datasource.dynamic.datasource.master.url=jdbc:mysql://127.0.0.1:3306/test?autoReconnect=true&useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=false&serverTimezone=Asia/Shanghai&allowMultiQueries=true
spring.datasource.dynamic.datasource.master.username=root
spring.datasource.dynamic.datasource.master.password=123456
spring.datasource.dynamic.datasource.master.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.dynamic.datasource.slave_1.url=jdbc:postgresql://127.0.0.1:45565/postgres
spring.datasource.dynamic.datasource.slave_1.username=root
spring.datasource.dynamic.datasource.slave_1.password=123456
spring.datasource.dynamic.datasource.slave_1.driver-class-name=org.postgresql.Driver

如果还有多个数据源的话，继续添加slave_xx就可以了
这里有个注意点spring.datasource.dynamic.primary=master 这里是指的默认的数据源，大家根据自身的情况调整。

代码实现

这里的话，我只是写的例子，所以比较简单。

model

@Setter
@Getter
public class TestMysql {
    private Integer id;
    private String name;
}

@Setter
@Getter
public class TestPg {
    private Integer id;
    private String name;
}

mapper

@Mapper
public interface TestMysqlMapper  extends BaseMapper<TestMysql> {

    TestMysql select();
}

@Mapper
public interface TestPgMapper extends BaseMapper<TestPg> {

    TestPg select();
}

xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.secusoft.demo.mapper.TestPgMapper">

    <select id="select" resultType="com.secusoft.demo.model.TestPg">
        select * from test.test_pg
    </select>
</mapper>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.secusoft.demo.mapper.TestMysqlMapper">

    <select id="select" resultType="com.secusoft.demo.model.TestMysql">
        select * from test_mysql
    </select>
</mapper>

service

public interface TestPgService  extends IService<TestPg> {
    TestPg select();
}

public interface TestMysqlService extends IService<TestMysql> {
    TestMysql select();
}

实现

@Service
@DS("slave_1")
public class TestPgServiceImpl  extends ServiceImpl<TestPgMapper, TestPg> implements TestPgService {

    @Override
    public TestPg select() {
        return this.baseMapper.select();
    }
}

@Service
public class TestMysqlServiceImpl extends ServiceImpl<TestMysqlMapper, TestMysql> implements TestMysqlService {


    @Override
    public TestMysql select() {
        return this.baseMapper.select();
    }
}

这里有个注意点:@DS(“slave_1”)注解 对应的就是上面写的slave_1，master可默认不写

controller

@RestController
@RequestMapping("/test")
public class TestController {

    @Resource
    private TestMysqlService testMysqlService;
    @Resource
    private TestPgService testPgService;



    @GetMapping("/sql")
    public Object sql() {
        TestMysql testMysql = testMysqlService.select();
        TestPg testPg = testPgService.select();
        List<Object> list=new ArrayList<>();
        list.add(testMysql);
        list.add(testPg);
        return list;
    }
    }

调用测试

完成。