package demo;

import java.io.IOException;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.ArrayList;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

/**

 * Servlet implementation class Queryalldata

 */

@WebServlet("/queryalldata.jsp")

public class Queryalldata extends HttpServlet {

	private static final long serialVersionUID = 1L;

    /**

     * @see HttpServlet#HttpServlet()

     */

    public Queryalldata() {

        super();

        // TODO Auto-generated constructor stub

    }

	/**

	 * @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)

	 */

	protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

		//查询所有数据

		//设置数据库连接参数

		String url="jdbc:mysql://localhost:3306/库名?serverTimezone=UTC";

		String user="用户名";

		String password="密码";

		//加载数据库驱动

		try {

			Class.forName("com.mysql.jdbc.Driver");//加载数据库的JDBC驱动程序

		} catch (ClassNotFoundException e) {

			e.printStackTrace();

		}

		List<Customer> list = new ArrayList<Customer>();//初始化一个Customer线性列表

		try(Connection connection=DriverManager.getConnection(url, user, password)){//连接数据库

			Statement statement = connection.createStatement();

			String sql="SELECT*FROM customers";//查询所有数据的sql语句,customers为表名

			ResultSet rs=statement.executeQuery(sql);

			//遍历数据库所有数据,并添加到列表list中

			while(rs.next()) {

				Customer customer = new Customer();

				customer.setCustomerID(rs.getInt("CustomerID"));

				customer.setCustomerName(rs.getString("CustomerName"));

				customer.setContactName(rs.getString("ContactName"));

				customer.setAddress(rs.getString("Address"));

				customer.setCity(rs.getString("City"));

				customer.setPostalCode(rs.getString("PostalCode"));

				customer.setCountry(rs.getString("Country"));

				list.add(customer);

			}

			rs.close();

			statement.close();

		}catch(SQLException e) {

			e.printStackTrace();

		}

		String msg =(String) request.getAttribute("msg");

		if(msg!=null || msg !=" ")

			request.setAttribute("msg", msg);

		//将有数据的列表传递到显示记录所有界面

		request.setAttribute("customers", list);

		request.getRequestDispatcher("all.jsp").forward(request, response);

	}

}