JDBC——建立数据库连接

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();
				}
			}
			
		}
	}
}