java mysql线程池

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class MySQLConnectionPoolExample {
    private static HikariDataSource dataSource;

    static {
        HikariConfig config = new HikariConfig();
        config.setJdbcUrl("jdbc:mysql://localhost:3306/mydatabase");
        config.setUsername("username");
        config.setPassword("password");
        config.setMaximumPoolSize(20);
        config.setConnectionTimeout(30000);
        dataSource = new HikariDataSource(config);
    }

    public static void main(String[] args) {
        try (Connection conn = dataSource.getConnection();
             PreparedStatement ps = conn.prepareStatement("SELECT * FROM users");
             ResultSet rs = ps.executeQuery()) {
            while (rs.next()) {
                System.out.println(rs.getString("username"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            dataSource.close();
        }
    }
}