一、用户登录：

采用之前的邮件登录系统的界面和验证

1 //设置数据格式

2 response.setContentType("text/html;charset=utf-8");3 request.setCharacterEncoding("utf-8");4 PrintWriter pw =response.getWriter();5

6 //获取值

7 String userID = request.getParameter("userID");8 String userPWD = request.getParameter("userPWD");9

10 //连接数据库

11 Connection conn;12

13 //数据库连接驱动(mysql8的连接需要加上cj)

14 String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";15

16 //需要使用的数据库路径

17 String url = "jdbc:mysql://localhost:3306/javaee?useSSL=false&serverTimezone=GMT%2B8";18

19 //数据库使用者信息

20 String user = "root";21 String password = "1234567890";22

23 try{24 Class.forName(JDBC_DRIVER);25 conn =DriverManager.getConnection(url, user ,password);26 if (!conn.isClosed()){27 System.out.println("数据库连接成功");28 }29 Statement stmt =conn.createStatement();30 String sql_select = "select * from userinfo where id='"+ userID +"' and password='"+ userPWD +"'";31 ResultSet result =stmt.executeQuery(sql_select);32 if(result.next()) {33 //登录成功的提示

34 System.out.println(userID + " " +userPWD);35 System.out.println("用户名：" + userID + " 密码:" +userPWD);36 System.out.println("登录成功，欢迎你 " +userID);37 pw.println("登录成功" + "
" + "您的用户名：" + userID + "
" + "您的密码：" +userPWD);38

39 //登录成功时设置Cookie

40 Cookie userCookie = new Cookie("userID", userID);41

42 //设置cookie保存的最大时间

43 userCookie.setMaxAge(60*60*24*30);44 response.addCookie(userCookie);45

46 //用户密码也用Cookie记录，方便自动登录

47 Cookie pwdCookie = new Cookie("userPWD", userPWD);48 userCookie.setMaxAge(60*60*24*30);49 response.addCookie(pwdCookie);50

51 //设置session

52 HttpSession session =request.getSession();53 session.setMaxInactiveInterval(10);54 ServletContext sc =getServletContext();55 Object number = sc.getAttribute("onlineNumber");56

57 pw.println("当前网页在线人数:" +number);58

59 }else{60 System.out.println("用户名或者密码错误");61 pw.println("登录失败"+"
"+"用户名或者密码错误");62 }63

64 //关闭数据库的连接

65 result.close();66 conn.close();67

68 }catch(ClassNotFoundException e){69 System.out.println("数据库驱动没有安装");70 e.printStackTrace();71 }catch(SQLException e){72 System.out.println("数据库连接失败");73 e.printStackTrace();74 }

login

二、新闻显示：

1、创建数据表：

1 CREATE DATABASE /*!32312 IF NOT EXISTS*/`NewsDB` /*!40100 DEFAULT CHARACTER SET utf8*/;2

3 USE `NewsDB`;4

5 /*Table structure for table `news`*/

6

7 DROP TABLE IF EXISTS `news`;8

9 CREATE TABLE `news` (10 `id` INT(11) NOT NULL AUTO_INCREMENT,11 `title` VARCHAR(100) DEFAULT NULL,12 `conetnt` VARCHAR(1000) DEFAULT NULL,13 `author` VARCHAR(50) DEFAULT NULL,14 `addtime` DATETIME DEFAULT NULL,15 PRIMARY KEY (`id`)16 ) ENGINE=INNODB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;17

18 /*Data for the table `news`*/

19

20 INSERT INTO `news`(`id`,`title`,`conetnt`,`author`,`addtime`) VALUES (1,'端午节的来源','端午节，又称端阳节、龙舟节、重午节、龙节、正阳节、天中节等，节期在农历五月初五，是中国民间的传统节日。端午节源自天象崇拜，由上古时代祭龙演变而来。仲夏端午，苍龙七宿飞升至正南中天，是龙飞天的日子，即如《易经·乾卦》第五爻的爻辞曰：“飞龙在天”。端午日龙星既“得中”又“得正”，乃大吉大利之象。端午节的起源涵盖了古老星象文化、人文哲学等方面内容，蕴含着深邃丰厚的文化内涵；在传承发展中杂揉了多种民俗为一体，节俗内容丰富。扒龙舟与食粽是端午节的两大礼俗，这两大礼俗在中国自古传承，至今不辍。','test','2020-06-25 10:19:42');21

22 /*Table structure for table `user`*/

23

24 DROP TABLE IF EXISTS `user`;25

26 CREATE TABLE `user` (27 `uid` INT(11) NOT NULL AUTO_INCREMENT,28 `userName` VARCHAR(30) DEFAULT NULL,29 `pw` VARCHAR(15) DEFAULT NULL,30 PRIMARY KEY (`uid`)31 ) ENGINE=INNODB AUTO_INCREMENT=6 DEFAULT CHARSET=gb2312;32

33 /*Data for the table `user`*/

34

35 INSERT INTO `user`(`uid`,`userName`,`pw`) VALUES (1,'admin','admin');

createdatabase

2、新增Servlet : NewsController.java 并配置在WEB.XML中

NewsController

servlet.NewsController

NewsController

/NewsController

在NewsController.java 中doGet中重写doPost方法并在doPost方法中获取action参数，根据参数不同分别进行不同请求

3、创建service类   NewsService.java，在类中调用DAO中并返回新闻信息

public classNewsService {public Listquery_all_news() {

NewsDao newsDao= newNewsDao();returnnewsDao.query_all_news();

}publicNewsBean getNews(String id) {

NewsDao newsDao= newNewsDao();returnnewsDao.getNews(id);

}

}

4、新增DBUtils.java 及 NewsDao.java类

在DBUtils.java中添加连接数据库及关闭数据库代码

public staticConnection getConnection(){

String dbUserName= "root";

String dbUserPasswd= "123456";

String dbURL= "jdbc:mysql://localhost:3406/NewsDB?serverTimezone=Asia/Shanghai";

Connection conn= null;try{

Class.forName("com.mysql.jdbc.Driver");

conn=(Connection) DriverManager.getConnection(dbURL,dbUserName,dbUserPasswd);

}catch (ClassNotFoundException |SQLException e) {

e.printStackTrace();

}returnconn;

}public static voidcloseConnection(Connection conn) {if(conn != null){try{

conn.close();

}catch(SQLException e) {//TODO: handle exception

e.printStackTrace();

}

}

}

public Listquery_all_news() {

Connection conn=DBUtils.getConnection();

String sql= "select * from news";

ArrayList results = new ArrayList();try{

PreparedStatement ps=(PreparedStatement) conn.prepareStatement(sql);

ResultSet rs=ps.executeQuery();while(rs.next()){

NewsBean temp= newNewsBean();

temp.setId(rs.getString("id"));

temp.setTitle(rs.getString("title"));

temp.setConetnt(rs.getString("conetnt"));

temp.setAuthor(rs.getString("author"));

temp.setAddtime(rs.getDate("addtime"));

results.add(temp);

}

rs.close();

ps.close();

}catch(SQLException e) {

e.printStackTrace();

}finally{

DBUtils.closeConnection(conn);

}returnresults;

}publicNewsBean getNews(String id) {

Connection conn=DBUtils.getConnection();

String sql= "select * from news where id='"+id+"' ";

NewsBean result= newNewsBean();try{

PreparedStatement ps=(PreparedStatement) conn.prepareStatement(sql);

ResultSet rs=ps.executeQuery();while(rs.next()){

result.setId(rs.getString("id"));

result.setTitle(rs.getString("title"));

result.setConetnt(rs.getString("conetnt"));

result.setAuthor(rs.getString("author"));

result.setAddtime(rs.getDate("addtime"));

}

rs.close();

ps.close();

}catch(SQLException e) {

e.printStackTrace();

}finally{

DBUtils.closeConnection(conn);

}returnresult;

}

5、前端显示页面：

${ctxt.title } ${ctxt.author } ${ctxt.addtime } 查看详情