java代码实现数据源切换(连接池简单粗暴)

--最佳实践配置（.yml）

gs.oracle:
  #driverClassName: oracle.jdbc.driver.OracleDriver
  driverClassName: oracle.jdbc.OracleDriver
  username: myuser
  password: root
  url: jdbc:oracle:thin:@127.0.0.1:1521:orcl

--最佳实践（注意在springboot的.yml中配置gs.oracle,若使用gs_oracle,@@ConfigurationProperties会提示使用规范配置）

package com.dhht.config;

import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

/**
 * @Author: sh
 * @Description: oracleDataCfg 前置数据库配置类
 * @Date: 9:26 2019/7/23
 */
@Component
@ConfigurationProperties(prefix = "gs.oracle")
@Data
public class OrcaleDataCfg {

    private String driverClassName;
    private String username;
    private String password;
    private String url;
}

--最佳实践DbConnect

package com.dhht.wechat.util;

import com.alibaba.druid.pool.DruidDataSource;
import com.dhht.config.OrcaleDataCfg;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Date;
import java.util.List;
import java.util.Map;

/**
 * @Author: sh
 * @Description: DbConnect
 * @Date: 23:01 2019/7/22
 */
@Component
public class DbConnect {

    @Resource
    OrcaleDataCfg orcaleDataCfg;

    private static DruidDataSource dataSource = null;
    private static JdbcTemplate jdbcTemplate = null;

    /**
     * 构造函数完成数据库的连接和连接对象的生成
     *
     * @throws Exception
     */
    private DbConnect() {

    }

    public synchronized DruidDataSource GetDbConnect() throws Exception {
        try {
            if (dataSource == null) {
                dataSource = new DruidDataSource();
                //设置连接参数
                dataSource.setUrl(orcaleDataCfg.getUrl());
                dataSource.setDriverClassName(orcaleDataCfg.getDriverClassName());
                dataSource.setUsername(orcaleDataCfg.getUsername());
                dataSource.setPassword(orcaleDataCfg.getPassword());
                //配置初始化大小、最小、最大
                dataSource.setInitialSize(5);
                dataSource.setMinIdle(5);
                dataSource.setMaxActive(5);
                //连接泄漏监测
                dataSource.setRemoveAbandoned(true);
                dataSource.setRemoveAbandonedTimeout(30);
                //配置获取连接等待超时的时间
                dataSource.setMaxWait(20000);
                //配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
                dataSource.setTimeBetweenEvictionRunsMillis(20000);
                //防止过期，Oracle必须添加 FROM DUAL!
                dataSource.setValidationQuery("SELECT 'x' FROM DUAL");
                dataSource.setTestWhileIdle(true);
                dataSource.setTestOnBorrow(true);
                return dataSource;
            }
        } catch (Exception e) {
            return null;
        }
        return null;
    }

    /**
     * 取得已经构造生成的数据库连接
     *
     * @return 返回数据库连接对象
     * @throws Exception
     */
    public Connection getConnect() throws Exception {
        Connection con = null;
        try {
            GetDbConnect();
            con = dataSource.getConnection();
        } catch (Exception e) {
            throw e;
        }
        return con;
    }

    public synchronized JdbcTemplate getJdbcTemplate() throws  Exception{
        DruidDataSource druidDataSource = GetDbConnect();
        if(jdbcTemplate==null){
            jdbcTemplate = new JdbcTemplate();
            jdbcTemplate.setDataSource(druidDataSource);
        }
        return jdbcTemplate;
    }

    public static void main(String[] args) throws Exception {
        DbConnect dbConnect = new DbConnect();
        Connection connection = dbConnect.getConnect();
        String sql = "SELECT * from DZHY_GAYZ_KZLOG";
        PreparedStatement ps = connection.prepareStatement(sql);
        ResultSet resultSet = ps.executeQuery();
        if (resultSet.next()) {
            System.out.println(resultSet.getInt(1));
        }
        JdbcTemplate jdbcTemplate = new JdbcTemplate();
        jdbcTemplate.setDataSource(dataSource);
        List<Map<String,Object>> list = jdbcTemplate.queryForList(sql);
        String SQL = "insert into DZHY_GAYZ_KZLOG (id,uniscid,entname,startdate,enddate,kz_uniscid,kz_entname) values (?,?,?,?,?,?,?)";
        jdbcTemplate.update(SQL,DateUtil.get32UUIDMilli(),"333","需要刻章33",new Date(),new Date(),"33-33","刻章店33");
    }
}