spring boot:使用mybatis访问多个mysql数据源/查看Hikari连接池的统计信息(spring boot 2.3.1)

一，为什么要访问多个mysql数据源?

实际的生产环境中，我们的数据并不会总放在一个数据库，

例如：业务数据库：存放了用户/商品/订单

        统计数据库：按年、月、日的针对用户、商品、订单的统计表

       因为统计库中的数据是对业务库中数据的提取和挖掘，

       但与业务的运行没有直接关系，所以我们会分开存放，

      把它们放到两个库中。

但有时我们会有访问两个库中数据的需求，这时就需要访问两个或以上数据源

说明：刘宏缔的架构森林是一个专注架构的博客，地址：https://www.cnblogs.com/architectforest

         对应的源码可以访问这里获取： https://github.com/liuhongdi/

说明：作者:刘宏缔 邮箱: 371125307@qq.com

二，演示项目的相关信息

1,项目地址:

https://github.com/liuhongdi/multimysql

2,项目原理

我们需要访问两个数据库，一个名字：store,

一个名字：tiku

然后在一个方法中获取到两个库中指定数据表的数据

3,项目结构，如图:

三，配置文件说明

1,application.properties

#mysql
spring.datasource.store.url=jdbc:mysql://127.0.0.1:3306/store?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=Asia/Shanghai
spring.datasource.store.username=root
spring.datasource.store.password=lhddemo
spring.datasource.store.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.store.maximum-pool-size=12
spring.datasource.store.minimum-idle=10
spring.datasource.store.idle-timeout=500000
spring.datasource.store.max-lifetime=540000

spring.datasource.tiku.url=jdbc:mysql://localhost:3306/tiku?useUnicode=true&characterEncoding=utf-8&useSSL=FALSE&serverTimezone=Asia/Shanghai
spring.datasource.tiku.username=root
spring.datasource.tiku.password=lhddemo
spring.datasource.tiku.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.tiku.maximum-pool-size=12
spring.datasource.tiku.minimum-idle=10
spring.datasource.tiku.idle-timeout=500000
spring.datasource.tiku.max-lifetime=540000

说明：我们需要访问两个数据库：store,tiku

注意max-lifetime的设置：这个值是连接池中一个连接的生命时间长度，

设置应该低于mysql配置文件中的wait-timeout值的设置，

idle-timeout是指空闲的连接的超时时间，应该不大于max-lifetime的值

maximum-pool-size是池中连接的数据，默认值是10，我们设置为12，保留默认值也没问题

2，两个数据表的结构:

store.goods

CREATE TABLE `goods` (
 `goodsId` int(11) NOT NULL AUTO_INCREMENT COMMENT 'id',
 `goodsName` varchar(500) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL DEFAULT '' COMMENT 'name',
 `subject` varchar(200) NOT NULL DEFAULT '' COMMENT '标题',
 `price` decimal(15,2) NOT NULL DEFAULT '0.00' COMMENT '价格',
 `stock` int(11) NOT NULL DEFAULT '0' COMMENT 'stock',
 PRIMARY KEY (`goodsId`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='商品表'

tiku.category

CREATE TABLE `category` (
 `category_id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'id',
 `category_name` varchar(100) NOT NULL DEFAULT '' COMMENT '分类名称',
 PRIMARY KEY (`category_id`),
 UNIQUE KEY `category_name` (`category_name`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='分类'

四，java代码说明

1,StoreDataSourceConfig.java

@Configuration
//得到mapper
@MapperScan(basePackages = StoreDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "storeSqlSessionFactory")
public class StoreDataSourceConfig {
    // 指定mapper 目录，与其他数据源隔离
    static final String PACKAGE = "com.multimysql.demo.mapper.store";
    static final String MAPPER_LOCATION = "classpath:mapper/store/*.xml";

    @Value("${spring.datasource.store.url}")
    private String url;

    @Value("${spring.datasource.store.username}")
    private String username;

    @Value("${spring.datasource.store.password}")
    private String password;

    @Value("${spring.datasource.store.driver-class-name}")
    private String driverClass;

    @Value("${spring.datasource.store.maximum-pool-size}")
    private int maximumPoolSize;

    @Value("${spring.datasource.store.minimum-idle}")
    private int minimumIdle;

    @Value("${spring.datasource.store.idle-timeout}")
    private long idleTimeout;

    @Value("${spring.datasource.store.max-lifetime}")
    private long maxLifetime;

    //得到datasource
    @Bean(name = "storeDataSource")
    @Primary
    public DataSource storeDataSource()  {
        HikariDataSource dataSource=new HikariDataSource();
        dataSource.setJdbcUrl(url);
        dataSource.setUsername(username);
        dataSource.setPassword(password);
        dataSource.setDriverClassName(driverClass);
        dataSource.setMaximumPoolSize(maximumPoolSize);
        dataSource.setMinimumIdle(minimumIdle);
        dataSource.setIdleTimeout(idleTimeout);
        dataSource.setMaxLifetime(maxLifetime);
        return dataSource;
    }

    //得到TransactionManager
    @Bean(name = "storeTransactionManager")
    @Primary
    public DataSourceTransactionManager storeTransactionManager() {
        return new DataSourceTransactionManager(storeDataSource());
    }

    //得到SqlSessionFactory
    @Bean(name = "storeSqlSessionFactory")
    @Primary
    public SqlSessionFactory storeSqlSessionFactory(@Qualifier("storeDataSource") DataSource storeDataSource)
            throws Exception {
        final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
        sessionFactory.setDataSource(storeDataSource);
        sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources(StoreDataSourceConfig.MAPPER_LOCATION));
        return sessionFactory.getObject();
    }
}

生成到store数据库的数据源,

注意指定了mapper文件的路径，

两个不同数据源的mapper分别放到了不同的目录下，避免有冲突

2,TikuDataSourceConfig.java,

   为节省篇幅，不再贴出代码，大家可以在github上自取

3,HomeController.java

@Controller
@RequestMapping("/home")
public class HomeController {

    @Resource
    private GoodsMapper goodsMapper;

    @Resource
    private CategoryMapper categoryMapper;

    @Resource
    private HikariDataSource storeDataSource;

    @Resource
    private HikariDataSource tikuDataSource;

    //商品详情 参数:商品id
    @GetMapping("/goodsone")
    @ResponseBody
    public String goodsOne(@RequestParam(value="goodsid",required = true,defaultValue = "0") Long goodsId) throws SQLException {
        System.out.println("------goodsInfo begin");
        Goods goods = goodsMapper.selectOneGoods(goodsId);
        Category category=categoryMapper.selectOneCategory("4");
        return "goods:"+goods.toString()+";category:"+category.toString();
    }

    //显示统计信息
    @GetMapping("/stats")
    @ResponseBody
    public Object stats() throws SQLException {

        Connection connection = storeDataSource.getConnection();
        connection.close();
        HikariPoolMXBean storePool = storeDataSource.getHikariPoolMXBean();
        int active = storePool.getActiveConnections();
        int total = storePool.getTotalConnections();
        int idle = storePool.getIdleConnections();
        int theadsAwaitting = storePool.getThreadsAwaitingConnection();
        int maximumPoolsize = storeDataSource.getMaximumPoolSize();
        int minimumIdle = storeDataSource.getMinimumIdle();
        String poolName = storeDataSource.getPoolName();
        long connTimeout = storeDataSource.getConnectionTimeout();
        long idleTimeout = storeDataSource.getIdleTimeout();
        long maxLifetime = storeDataSource.getMaxLifetime();

        String status = "store pool:<br/>";
        status += "poolName:" + poolName+"<br/>";
        status += "active:" + active+"<br/>";
        status += "total:" + total+"<br/>";
        status += "idle:" + idle+"<br/>";
        status += "theadsAwaitting:" + theadsAwaitting+"<br/>";
        status += "maximumPoolsize:" + maximumPoolsize+"<br/>";
        status += "minimumIdle:" + minimumIdle+"<br/>";
        status += "connTimeout:" + connTimeout+"<br/>";
        status += "idleTimeout:" + idleTimeout+"<br/>";
        status += "maxLifetime:" + maxLifetime+"<br/>";

        Connection tikuConnection = tikuDataSource.getConnection();
        tikuConnection.close();
        HikariPoolMXBean tikuPool = tikuDataSource.getHikariPoolMXBean();
        int active2 = tikuPool.getActiveConnections();
        int total2 = tikuPool.getTotalConnections();
        int idle2 = tikuPool.getIdleConnections();
        int theadsAwaitting2 = tikuPool.getThreadsAwaitingConnection();
        int maximumPoolsize2 = tikuDataSource.getMaximumPoolSize();
        int minimumIdle2 = tikuDataSource.getMinimumIdle();
        String poolName2 = tikuDataSource.getPoolName();
        long connTimeout2 = tikuDataSource.getConnectionTimeout();
        long idleTimeout2 = tikuDataSource.getIdleTimeout();
        long maxLifetime2 = tikuDataSource.getMaxLifetime();

        status += "tiku pool:<br/>";
        status += "poolName:" + poolName2+"<br/>";
        status += "active:" + active2+"<br/>";
        status += "total:" + total2+"<br/>";
        status += "idle:" + idle2+"<br/>";
        status += "theadsAwaitting:" + theadsAwaitting2+"<br/>";
        status += "maximumPoolsize:" + maximumPoolsize2+"<br/>";
        status += "minimumIdle:" + minimumIdle2+"<br/>";
        status += "connTimeout:" + connTimeout2+"<br/>";
        status += "idleTimeout:" + idleTimeout2+"<br/>";
        status += "maxLifetime:" + maxLifetime2+"<br/>";

         return status;
    }

说明：goodsOne方法：返回store.goods表中的商品信息和tiku.category表中的分类信息

         stats方法：打印两个Hikari连接池的信息

4,其他的 类文件和mapper文件，请访问github获取

五，效果测试

1,访问商品信息地址:

http://127.0.0.1:8080/home/goodsone?goodsid=3

返回:

goods: Goods:goodsId=3 goodsName=100分电动牙刷 subject=好用到让你爱上刷牙 price=59.00 stock=15
category: Goods:category_id=4 category_name=bash

2,访问统计地址:

http://127.0.0.1:8080/home/stats

返回:

store pool:
poolName:HikariPool-1
active:0
total:10
idle:10
theadsAwaitting:0
maximumPoolsize:12
minimumIdle:10
connTimeout:30000
idleTimeout:500000
maxLifetime:540000

tiku pool:
poolName:HikariPool-2
active:0
total:10
idle:10
theadsAwaitting:0
maximumPoolsize:12
minimumIdle:10
connTimeout:30000
idleTimeout:500000
maxLifetime:540000

六，查看spring boot的版本

  .   ____          _            __ _ _
 /\ / ___'_ __ _ _(_)_ __  __ _    
( ( )\___ | '_ | '_| | '_ / _` |    
 \/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v2.3.1.RELEASE)