每日日报2021.5.17

今天完成内容：

学习web

 连接数据库，完成查询项目

package servlet;

import java.io.IOException;
import java.util.ArrayList;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import bean.User;
import dao.UserDao;

@WebServlet("/Select")
public class Select extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public Select() {
super();
// TODO Auto-generated constructor stub
}

/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("utf-8");
String dp = request.getParameter("dp");
String ap = request.getParameter("ap");
String ndate = request.getParameter("ndate");
ArrayList<User> list=new ArrayList<>();
UserDao dao=new UserDao();
list=dao.search(dp,ap,ndate);
System.out.println("aaa");
request.setAttribute("list", list);
request.getRequestDispatcher("lalala.jsp").forward(request, response);
}

/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}

}

package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DBUtil {

private static final String db_url="jdbc:mysql://localhost:3306/jichang?useUnicode=true&characterEncoding=GB18030&useSSL=false&serverTimezone=GMT&allowPublicKeyRetrieval=true";
public static String db_user = "root";
public static String db_pass = "123456";

public static Connection getConn () {
Connection conn = null;

try {
Class.forName("com.mysql.cj.jdbc.Driver");
conn = DriverManager.getConnection(db_url, db_user, db_pass);
} catch (Exception e) {
e.printStackTrace();
}

return conn;
}

/**
* 锟截憋拷锟斤拷锟斤拷
* @param state
* @param conn
*/
public static void close (Statement state, Connection conn) {
if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}

public static void close (ResultSet rs, Statement state, Connection conn) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

if (state != null) {
try {
state.close();
} catch (SQLException e) {
e.printStackTrace();
}
}

if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}

看视频

遇到问题：

无

明日目标：

学习web端的开发

学习css