Springboot-HikariCP 实现动态数据源切换

作者：网络抖动

原文地址 https://www.jianshu.com/p/05a8a1a2b50c

gitHub 项目地址：https://github.com/shizhenshuang123/hikaricp-demo

开发环境：

• jdk：JDK1.8+

• gradle：Gradle4.6+

• Spring：2.1.3.RELEASE+

当数据库数据达到一定数量的时候，数据库的响应将会有所缓慢，一般都会采取一些措施。例如，读写分离、分表分库、主从服务、缓存技术等等。这里采用的是多库多表。

test 库中 user_info 表：

test2 库中 user_info 表：

导入依赖

    compile group: 'org.springframework.boot', name: 'spring-boot-starter-web', version: '2.1.3.RELEASE'
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-jdbc', version: '2.1.3.RELEASE'
    compileOnly group: 'org.projectlombok', name: 'lombok', version: '1.18.6'
    compile group: 'mysql', name: 'mysql-connector-java', version: '8.0.15'
    compile group: 'org.mybatis.generator', name: 'mybatis-generator-core', version: '1.3.5'
    compile group: 'tk.mybatis', name: 'mapper', version: '4.0.2'
    compile group: 'org.mybatis.spring.boot', name: 'mybatis-spring-boot-starter', version: '2.0.0'

HikariCP 在 spring-boot-starter-jdbc 中已经被引入（Spring 默认数据源）

项目结构

配置文件配置（application.yaml）默认数据源信息

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=CONVERT_TO_NULL&serverTimezone=Asia/Shanghai&allowMultiQueries=true
    username: root
    password: admin
    sql-script-encoding: UTF-8

读取配置信息 DataSourceConfig.java，创建默认的数据源

package utry.hikaricp.config;
import com.zaxxer.hikari.HikariDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.transaction.annotation.EnableTransactionManagement;
import utry.hikaricp.DataSourceProvider;
import utry.hikaricp.info.DataSourceInfo;
import utry.hikaricp.source.MyHikariDataSource;
@Configuration
@EnableTransactionManagement
public class DataSourceConfig {
    @Value("${spring.datasource.url}")
    private String url;
    @Value("${spring.datasource.username}")
    private String userName;
    @Value("${spring.datasource.password}")
    private String password;
    @Bean
    @ConditionalOnMissingBean(MyHikariDataSource.class)
    public MyHikariDataSource dataSource() {
        DataSourceInfo info = new DataSourceInfo();
        info.setUrl(url);
        info.setUsername(userName);
        info.setPassword(password);
        HikariDataSource dataSource = DataSourceProvider.create(info);
        MyHikariDataSource hikariCPDataSource = new MyHikariDataSource();
        hikariCPDataSource.updateDataSourceMap("1", dataSource);
        return hikariCPDataSource;
    }
}

通过 DataSourceProvider 创建 HikariDataSource

package utry.hikaricp;
import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;
import utry.hikaricp.info.DataSourceInfo;
public class DataSourceProvider {
    public static HikariDataSource create(DataSourceInfo sourceInfo) {
        HikariConfig hikariConfig = new HikariConfig();
        hikariConfig.setUsername(sourceInfo.getUsername());
        hikariConfig.setPassword(sourceInfo.getPassword());
        hikariConfig.setJdbcUrl(sourceInfo.getUrl());
        hikariConfig.setDriverClassName("com.mysql.jdbc.Driver");
        return new HikariDataSource(hikariConfig);
    }
}

最核心的数据源的类 MyHikariDataSource.java

package utry.hikaricp.source;
import com.zaxxer.hikari.HikariDataSource;
import org.springframework.jdbc.datasource.AbstractDataSource;
import javax.sql.DataSource;
import java.io.Closeable;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
public class MyHikariDataSource extends AbstractDataSource {
    private static Map dataSourceMap = new HashMap<>(1);
    @Override
    public Connection getConnection() throws SQLException {
        return dataSourceMap.get("1").getConnection();
    }
    @Override
    public Connection getConnection(String username, String password) throws SQLException {
        return dataSourceMap.get("1").getConnection(username, password);
    }
    private void destroy(){
        DataSource dataSource = dataSourceMap.get("1");
        Closeable closeable = (Closeable) dataSource;
        if (closeable != null) {
            try {
                closeable.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    public void updateDataSourceMap(String key, HikariDataSource value) {
        destroy();
        dataSourceMap.put(key, value);
    }
}

只要将上面这个类中的 DataSourceMap 集合中的 HikariDataSource 修改就能实现数据源的切换了，调用 updateDataSourceMap() 方法修改即可（修改之前，先关闭之前的数据源，这里写死的 map 中 key=1，读者可以实现动态设置）

---

实体类 UserInfo.java

package utry.hikaricp.model;
public class UserInfo {
    private Integer id;
    private String remarks;
    public UserInfo() {
    }
    public UserInfo(Integer id, String remarks) {
        this.id = id;
        this.remarks = remarks;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getRemarks() {
        return remarks;
    }
    public void setRemarks(String remarks) {
        this.remarks = remarks;
    }
}

HikariCpController.java 两个接口：

1. 更新数据源

2. 查询用户信息

package utry.hikaricp.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import utry.hikaricp.factory.HikariCPDataSourceFactory;
import utry.hikaricp.mapper.UserInfoMapper;
import utry.hikaricp.model.UserInfo;
@RestController
public class HikariCpController {
    @Autowired
    private UserInfoMapper mapper;
    @Autowired
    private HikariCPDataSourceFactory factory;
    @RequestMapping("update")
    public void info(String username, String password, String url) {
        factory.reload(username, password, url);
    }
    @RequestMapping("get")
    public UserInfo get() {
        try {
            UserInfo userInfo = mapper.selectByPrimaryKey(1);
            return userInfo;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}

启动项目

1、调用 get 接口，返回的数据是 test 库中的

2、调用 update 请求更新数据源

调用成功之后，可以看到，之前的数据源已经被 shutdown，初始化了一个新的数据源

3、再次调用 get 请求，可以看到获取的 test2 数据库中的数据

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