java-多数据源切换-非切面

非切面方式：

配置文件：自己的数据库连接

 datasource:
    primary:
      jdbc-url: 你的数据库1连接地址
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: user
      password: password
    secondary:
      jdbc-url: 你的数据库2连接地址
      driver-class-name: com.mysql.cj.jdbc.Driver
      username: user
      password: password

数据源的配置文件：

package com.qf.config;

import com.zaxxer.hikari.HikariDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.beans.factory.annotation.Qualifier;
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.core.annotation.Order;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;


import javax.sql.DataSource;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;


@Configuration
public class DataSourceConfig {
    @Bean(name = "primaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.primary")
    public DataSource db1DataSource() {
        return new HikariDataSource();
    }


    @Bean(name = "secondaryDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.secondary")
    public DataSource db2DataSource() {
        return new HikariDataSource();
    }
}

@ConfigurationProperties注解里面的参数，对应的是配置文件中的路径，这里会直接创建为DataSource类。这里有两个数据源，所以通过@Bean的name参数来区分数据源。这个类只是加载数据源就行。

以下是将多数据源进行分开配置，一个数据源一个配置文件：

主数据源：

package com.qf.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
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 org.springframework.context.annotation.Primary;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import tk.mybatis.spring.annotation.MapperScan;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.qf.mapper.db1", sqlSessionFactoryRef = "primarySqlSessionFactory")
public class PrimaryDataSourceConfig {

    // 之前加载好的数据源，进行引入
    @Autowired
    @Qualifier("primaryDataSource")
    private DataSource primaryDataSource;


    @Bean(name = "primarySqlSessionFactory")
    @Primary
    public SqlSessionFactory primarySqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(primaryDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/db1/*.xml"));
        return sessionFactory.getObject();
    }

    @Bean
    @Primary
    public PlatformTransactionManager primaryTransactionManager() {
        return new DataSourceTransactionManager(primaryDataSource);
    }
}

这里需要注意的事情是@MapperScan注解需要是tk.mybatis.spring.annotation.MapperScan;包下面的。否则会切换失败， basePackages  这个的参数就是主数据库的实体类对应的mapper的位置。sqlSessionFactoryRef 这个参数是给这个数据源配置一个工厂。就是primarySqlSessionFactory() 方法返回的工厂。

classpath*:mapper/db1/*.xml ： 换为自己这个数据源对应的xml地址就行

@Primary 注解是声明这个数据源为主数据源，在没确认数据源的情况下，会自动使用这个数据源

次级数据源：

package com.qf.config;

import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
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 org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import tk.mybatis.spring.annotation.MapperScan;

import javax.sql.DataSource;

@Configuration
@MapperScan(basePackages = "com.qf.mapper.db2", sqlSessionFactoryRef = "secondarySqlSessionFactory")
public class SecondaryDataSourceConfig {

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

    @Bean(name = "secondarySqlSessionFactory")
    public SqlSessionFactory secondarySqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(secondaryDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/db2/*.xml"));
        return sessionFactory.getObject();
    }

    @Bean
    public PlatformTransactionManager secondaryTransactionManager() {
        return new DataSourceTransactionManager(secondaryDataSource);
    }
}

注意： 这里就不要加@Primary注解，其他都是一样的。

示例：

启动类：

controller:

package com.qf.controller;

import com.qf.config.QFDataSource;
import com.qf.service.IOrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.annotation.Resource;

@RestController
@RequestMapping("order")
public class OrderController {

    @Autowired
    private IOrderService iOrderService;

    /**
     * 添加上数据
     * @return
     */
    @PostMapping("/createOrder")
    public Object createOrder() {
        return iOrderService.createOrder();
    }
}

service:

package com.qf.service.impl;

import com.qf.demo.entity.QfOrder;
import com.qf.mapper.db2.QfOrderMapper;
import com.qf.service.IOrderService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


@Service
public class IOrderServiceImpl implements IOrderService {

    @Autowired
    private QfOrderMapper qfOrderMapper;

    @Override
    public Object createOrder() {
        QfOrder order = new QfOrder();
        order.setOrderNumber("515151561");
        order.setName(555.223);
        order.setAmount(123.23);
        qfOrderMapper.insert(order);
        return order;
    }
}

mapper:

package com.qf.mapper.db2;

import com.qf.demo.entity.QfOrder;
import tk.mybatis.mapper.common.Mapper;

/**
* @author Administrator
* @description 针对表【qf_order】的数据库操作Mapper
* @createDate 2024-12-02 14:12:31
* @Entity com.qf.demo.entity.QfOrder
*/
public interface QfOrderMapper extends Mapper<QfOrder> {


}

我的包路径：

数据库：