JDBC建立数据库连接的代码

import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
 
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;
 
public class Test {
  public static void main(String[] args) {
     
    //声明Connection对象
    Connection conn = null;
    PreparedStatement preparedStatement = null;
    ResultSet resultSet = null;
    //驱动程序名
    String driver = "com.mysql.jdbc.Driver";
    //用户名
    String user = "root";
    //密码
    String password = "1234";
    //url
    String url = "jdbc:mysql://localhost:3306/db_person";
     
    try {
      String sql = "SELECT * FROM student";
      //1.加载驱动
      Class.forName(driver);
      //2.获得connect连接
      conn = (Connection) DriverManager.getConnection(url, user, password);
      //3.获得PreparedStatement
      preparedStatement = (PreparedStatement) conn.prepareStatement(sql);
      //4.获得结果集
      resultSet = preparedStatement.executeQuery();
       
      while(resultSet.next()) {
        int id = resultSet.getInt(1);
        String name = resultSet.getString(2);
        String sex = resultSet.getString(3);
        int age = resultSet.getInt(4);
         
        System.out.println(id +" "+ name + " " + sex + " " + age);
      }
       
    } catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally {
      if(resultSet != null) {
        try {
          resultSet.close();
        } catch (SQLException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
      }
       
      if(preparedStatement != null) {
        try {
          preparedStatement.close();
        } catch (SQLException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
      }
       
      if(conn != null) {
        try {
          conn.close();
        } catch (SQLException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
      }
       
    }
  }
}