mysql数据库连接类

首先在maven项目的 pom 文件添加以下依赖

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.20</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.13</version>
</dependency>

java 代码如下

/**
 * @description: 数据库连接工具类
 * @author: xxzuo
 * @email: 1293378490@qq.com
 * @date: 2022/6/17 14:42
 **/
public class DbUtils {
    private static DruidDataSource dataSource;

    public static Connection getConnection() throws Exception {
        dataSource = new DruidDataSource();
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUrl("jdbc:mysql://localhost:3306/xxxxx");
        dataSource.setUsername("root");
        dataSource.setPassword("123456");
        //设置初始化连接数，最大连接数，最小闲置数
        dataSource.setInitialSize(10);
        dataSource.setMaxActive(50);
        dataSource.setMinIdle(5);
        //返回连接
        return  dataSource.getConnection();
    }

    public static Connection getConnection(String jdbc, String userName, String password) throws Exception {
        dataSource = new DruidDataSource();
        dataSource.setDriverClassName("com.mysql.cj.jdbc.Driver");
        dataSource.setUrl(jdbc);
        dataSource.setUsername(userName);
        dataSource.setPassword(password);
        //设置初始化连接数，最大连接数，最小闲置数
        dataSource.setInitialSize(10);
        dataSource.setMaxActive(50);
        dataSource.setMinIdle(5);
        //返回连接
        return  dataSource.getConnection();
    }
}

调用方法

public static void main(String[] args) {
    try (Connection connection = DbUtils.getConnection()) {
        String sql = "SELECT COL_NAME FROM TABLE_NAME";
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        ResultSet rs = preparedStatement.executeQuery();
        while (rs.next()) {
            rs.getString("COL_NAME");
        }
    } catch (Exception e) {

    }
}