Spring Boot 整合多数据源

超、凢脫俗 2022-03-21 11:46 221阅读 0赞

Spring Boot 整合多数据源  
我们先创建一个maven项目：

创建两个数据库test01和test02，并且都创建一个user表

配置pom.xml  
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  
  <modelVersion>4.0.0</modelVersion>  
  <groupId>com.cc.springboot</groupId>  
  <artifactId>springboot-many-mybatis</artifactId>  
  <version>0.0.1-SNAPSHOT</version>

<parent>  
        <groupId>org.springframework.boot</groupId>  
        <artifactId>spring-boot-starter-parent</artifactId>  
        <version>1.3.2.RELEASE</version>  
        <relativePath />   
    </parent>

<dependencies>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter</artifactId>  
        </dependency>  
        <dependency>  
            <groupId>org.mybatis.spring.boot</groupId>  
            <artifactId>mybatis-spring-boot-starter</artifactId>  
            <version>1.1.1</version>  
        </dependency>  
        <dependency>  
            <groupId>mysql</groupId>  
            <artifactId>mysql-connector-java</artifactId>  
        </dependency>  
        <dependency>  
            <groupId>org.springframework.boot</groupId>  
            <artifactId>spring-boot-starter-web</artifactId>  
        </dependency>  
    </dependencies>  
</project>  
  
配置文件中新增两个数据源  
application.properties

spring.datasource.test1.driverClassName = com.mysql.jdbc.Driver  
spring.datasource.test1.url = jdbc:mysql://localhost:3306/test01?useUnicode=true&characterEncoding=utf-8  
spring.datasource.test1.username = root  
spring.datasource.test1.password = root

spring.datasource.test2.driverClassName = com.mysql.jdbc.Driver  
spring.datasource.test2.url = jdbc:mysql://localhost:3306/test02?useUnicode=true&characterEncoding=utf-8  
spring.datasource.test2.username = root  
spring.datasource.test2.password = root  
  
创建分包Mapper  
分包创建User1Mapper和User2Mapper

package com.cc.springboot.test01;

import org.apache.ibatis.annotations.Insert;  
import org.apache.ibatis.annotations.Param;

public interface User1Mapper \{

@Insert("insert into users values(\#\{id\},\#\{username\});")  
    public int addUser(@Param("id") Integer id, @Param("username") String username);

\}  
  
package com.cc.springboot.test02;

import org.apache.ibatis.annotations.Insert;  
import org.apache.ibatis.annotations.Param;

public interface User2Mapper \{

@Insert("insert into users values(\#\{id\},\#\{username\});")  
    public int addUser(@Param("id") Integer id, @Param("username") String username);  
\}  
  
配置文件中新增两个数据源

package com.cc.springboot.datasource;

import javax.sql.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.autoconfigure.jdbc.DataSourceBuilder;  
import org.springframework.boot.context.properties.ConfigurationProperties;  
import org.springframework.context.annotation.Bean;  
import org.springframework.context.annotation.Configuration;  
import org.springframework.context.annotation.Primary;  
import org.springframework.jdbc.datasource.DataSourceTransactionManager;

@Configuration // 注册到springboot容器中  
@MapperScan(basePackages = "com.cc.springboot.test01", sqlSessionFactoryRef = "test1SqlSessionFactory")  
public class DataSource1Config \{

/\*\*   
     \*配置test1数据库  
     \*/  
    @Bean(name = "test1DataSource")  
    @Primary  
    @ConfigurationProperties(prefix = "spring.datasource.test1")  
    public DataSource testDataSource() \{  
        return DataSourceBuilder.create().build();  
    \}

/\*   
     \* test1 sql会话工厂  
     \*/  
    @Bean(name = "test1SqlSessionFactory")  
    @Primary  
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("test1DataSource") DataSource dataSource)  
            throws Exception \{  
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();  
        bean.setDataSource(dataSource);  
//      bean.setMapperLocations(  
//              new PathMatchingResourcePatternResolver().getResources("classpath:mybatis/mapper/test1/\*.xml"));  
        return bean.getObject();  
    \}

/\*\*  
     \*test1 事物管理  
     \*/  
    @Bean(name = "test1TransactionManager")  
    @Primary  
    public DataSourceTransactionManager testTransactionManager(@Qualifier("test1DataSource") DataSource dataSource) \{  
        return new DataSourceTransactionManager(dataSource);  
    \}

@Bean(name = "test1SqlSessionTemplate")  
    public SqlSessionTemplate testSqlSessionTemplate(  
            @Qualifier("test1SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception \{  
        return new SqlSessionTemplate(sqlSessionFactory);  
    \}

\}  
  
package com.cc.springboot.datasource;

import javax.sql.DataSource;

@Configuration // 注册到springboot容器中  
@MapperScan(basePackages = "com.cc.springboot.test02", sqlSessionFactoryRef = "test2SqlSessionFactory")  
public class DataSource2Config \{

/\*\*   
     \*配置test2数据库  
     \*/  
    @Bean(name = "test2DataSource")  
    @ConfigurationProperties(prefix = "spring.datasource.test2")  
    public DataSource testDataSource() \{  
        return DataSourceBuilder.create().build();  
    \}

/\*   
     \* test2 sql会话工厂  
     \*/  
    @Bean(name = "test2SqlSessionFactory")  
    public SqlSessionFactory testSqlSessionFactory(@Qualifier("test2DataSource") DataSource dataSource)  
            throws Exception \{  
        SqlSessionFactoryBean bean = new SqlSessionFactoryBean();  
        bean.setDataSource(dataSource);  
//      bean.setMapperLocations(  
//              new PathMatchingResourcePatternResolver().getResources("classpath:mybatis/mapper/test2/\*.xml"));  
        return bean.getObject();  
    \}

/\*\*  
     \*test2 事物管理  
     \*/  
    @Bean(name = "test2TransactionManager")  
    public DataSourceTransactionManager testTransactionManager(@Qualifier("test2DataSource") DataSource dataSource) \{  
        return new DataSourceTransactionManager(dataSource);  
    \}

@Bean(name = "test2SqlSessionTemplate")  
    public SqlSessionTemplate testSqlSessionTemplate(  
            @Qualifier("test2SqlSessionFactory") SqlSessionFactory sqlSessionFactory) throws Exception \{  
        return new SqlSessionTemplate(sqlSessionFactory);  
    \}

分包创建service

package com.cc.springboot.service.test01;

import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.stereotype.Service;

import com.cc.springboot.test01.User1Mapper;

@Service  
public class User1Service \{  
    @Autowired  
    private User1Mapper user1Mapper;

public int addUser(Integer id, String name) \{  
        return user1Mapper.addUser(id, name);  
    \}

\}  
  
package com.cc.springboot.service.test02;

import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.stereotype.Service;  
import org.springframework.transaction.annotation.Transactional;

import com.cc.springboot.test02.User2Mapper;

@Service  
public class User2Service \{  
    @Autowired  
    private User2Mapper user2Mapper;

public int addUser(Integer id, String name) \{  
        return user2Mapper.addUser(id, name);  
    \}

\}  
  
创建Controller  
package com.cc.springboot.controller;

import org.springframework.beans.factory.annotation.Autowired;  
import org.springframework.web.bind.annotation.RequestMapping;  
import org.springframework.web.bind.annotation.RestController;

import com.cc.springboot.service.test01.User1Service;  
import com.cc.springboot.service.test02.User2Service;

@RestController  
public class IndexController \{  
    @Autowired  
    private User1Service user1Service;  
    @Autowired  
    private User2Service user2Service;

@RequestMapping("/add")  
    public String index() \{  
        user1Service.addUser(1,"db user001");  
        user2Service.addUser(2,"db user002");  
        return "success";  
    \}

\}  
  
创建启动类  
package com.cc.springboot.app;

import org.springframework.boot.SpringApplication;  
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;  
import org.springframework.context.annotation.ComponentScan;

@ComponentScan(basePackages = \{"com.cc.springboot.controller","com.cc.springboot.test01","com.cc.springboot.test02","com.cc.springboot.service","com.cc.springboot.datasource"\})  
@EnableAutoConfiguration  
public class App \{  
    public static void main(String\[\] args) \{  
        SpringApplication.run(App.class, args);  
    \}  
\}  
  
测试  
启动：

注意事项  
如果去掉DataSource1Config配置中的@Primary会发生什么？?

发现报错了：

错误原因：No qualifying bean of type \[javax.sql.DataSource\] is defined: expected single matching bean but found 2: test1DataSource,test2DataSource   
给其中一个数据源加上@Primary。因为在Spring Boot Jdbc的自动配置过程中，会对于开发者透明地使用dataSource进行一些相关配置，所以当有两个Datasource实现类时，Spring Boot将无法确定使用哪一个。

DataSource1Config配置中的注解的具体解释：

@Primary：指定在同一个接口有多个实现类可以注入的时候，默认选择哪一个，而不是让@Autowire注解报错（一般用于多数据源的情况下）  
@Qualifier：指定名称的注入，当一个接口有多个实现类的时候使用（在本例中，有两个DataSource类型的实例，需要指定名称注入）  
@Bean：生成的bean实例的名称是方法名（例如上边的@Qualifier注解中使用的名称是前边两个数据源的方法名，而这两个数据源也是使用@Bean注解进行注入的）  
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原文：https://blog.csdn.net/cckevincyh/article/details/79187959