- 操作系统:Windows 10
- 软件环境:jdk1.8 、Tomcat9
- 开发工具:IntelliJ IDEA 2020
<%--
Created by IntelliJ IDEA.
User: Timber
Date: 2020/12/11
Time: 9:22
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录页面</title>
</head>
<body>
<form action="/JAVAWEB/loginServlet" method="post">
<label>
<input type="text" placeholder="请输入用户名" name="username">
</label><br>
<label>
<input type="password" placeholder="请输入密码" name="password">
</label><br>
<input type="submit" value="登录">
<br>
</form>
</body>
</html>
需求中提到密码框不能显示明文,故应使用 type="password"
action="/JAVAWEB/loginServlet" 是登录程序Servlet路径
method="post" 请求方法为 POST
package cn.timber.servlet;
import cn.timber.mysql.HkMysql;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
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 javax.servlet.http.HttpSession;
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//获取用户名和密码
String username = request.getParameter("username");
String password = request.getParameter("password");
//后端控制台输出
System.out.println(username+" "+password);
//密码匹配接口
String myPwd = "123456";
HttpSession session=request.getSession();
session.setAttribute("username", username);
//信息加入数据库
String sqlINFO = new HkMysql().mysqlHK(request.getParameter("username"), request.getRemoteAddr(), new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
System.out.println(sqlINFO);
//密码判断
if(password.equals(myPwd)) {
//重定向到登录成功页面
response.sendRedirect(request.getContextPath()+"/loginSuccess.jsp?username="+ username);
}else {
//重定向到登录失败页面
response.sendRedirect(request.getContextPath()+"/loginFail.jsp?username="+ username);
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request , response);
}
}
package cn.timber.mysql;
import java.sql.*;
public class HkMysql {
static final String JDBC_DRIVER = "com.mysql.cj.jdbc.Driver";
static final String DB_URL = "jdbc:mysql://0.0.0.0:3306/javaweb?useSSL=false&allowPublicKeyRetrieval=true&serverTimezone=UTC";
// 数据库的用户名与密码
static final String USER = "root";
static final String PASS = "123456";
public String mysqlHK (String username , String ipaddr , String loginTime) {
Connection conn = null;
Statement stmt = null;
Statement statement = null;
try {
// 注册 JDBC 驱动
Class.forName(JDBC_DRIVER);
// 打开链接
System.out.println("连接数据库...");
conn = DriverManager.getConnection(DB_URL, USER, PASS);
// 执行查询
System.out.println(" 实例化Statement对象...");
stmt = conn.createStatement();
String sql;
//添加数据
String sql1 = "insert into javaweb.javaweblogin values ('"+username+"','"+ipaddr+"','"+loginTime+"');";
statement = conn.createStatement();
statement.executeUpdate(sql1);
sql = "SELECT * FROM javaweblogin";
ResultSet rs = stmt.executeQuery(sql);
//ResultSet rs1 = stmt.executeQuery(sql);//创建数据对象
while (rs.next()) {
// 通过字段检索
String id = rs.getString("IP地址");
String name = rs.getString("用户名");
String time = rs.getString("提交时间");
// 输出数据
System.out.print("ip: " + id);
System.out.print(", 用户名: " + name);
System.out.print(", 提交时间: " + time);
System.out.print("\n");
}
// 完成后关闭
rs.close();
stmt.close();
conn.close();
} catch (SQLException se) {
// 处理 JDBC 错误
se.printStackTrace();
} catch (Exception e) {
// 处理 Class.forName 错误
e.printStackTrace();
} finally {
// 关闭资源
try {
if (stmt != null) stmt.close();
} catch (SQLException se2) {
}// 什么都不做
try {
if (conn != null) conn.close();
} catch (SQLException se) {
se.printStackTrace();
}
}
return "已加入数据库";
}
}
++注:需要JDBC环境依赖++
下载地址:https://downloads.mysql.com/archives/c-j/
在web目录中WEB-INF包中创建lib目录导入jar包即可
<%--
Created by IntelliJ IDEA.
User: Timber
Date: 2020/12/11
Time: 9:43
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title><%
out.print(request.getParameter("username"));
%>登录成功</title>
<script src="jquery-3.5.1.js"></script>
<script>
$(function() {
//toRight
$("#toRight").click(function() {
//获取右边的下拉列表对象,append(左边下拉列表选中的option)
$("#rightName").append($("#leftName > option:selected"));
});
});
</script>
<style>
#leftName, #btn, #rightName {
width: 100px;
height: 300px;
}
#toRight {
margin-top: 100px;
margin-left: 30px;
width: 50px;
}
.border {
height: 500px;
padding: 100px;
}
</style>
</head>
<body>
登陆成功<br>
欢迎您:<br>
<font color="red" size="22" >
<%
out.print(request.getParameter("username")+"<br>");
%>
</font>
<a href="<%=request.getContextPath()%>/index.jsp">重新登录</a>
<form action="/JAVAWEB/heroServlet" method="post" >
<div class="border">
英雄:
<select id="leftName" multiple="multiple">
<option value="葫芦娃">葫芦娃</option>
<option value="一只耳">一只耳</option>
<option value="美国队长">美国队长</option>
<option value="黑猫警长">黑猫警长</option>
<option value="唐老鸭的情妇">唐老鸭的情妇</option>
</select>
</select> <input type="button" id="toRight" value="-->"> 败类:
<select id="rightName" name="bailei" multiple="multiple">
</select>
<br/>
<input type="submit" value="提交">
</div>
</form>
</div>
</body>
</html>
<%--
Created by IntelliJ IDEA.
User: Timber
Date: 2020/12/11
Time: 9:51
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登陆失败</title>
</head>
<body>
<h1>用户名<%out.print(request.getParameter("username"));%>与密码不匹配,请重新登录</h1>
<a href="<%=request.getContextPath()%>/index.jsp"><h2>重新登录</h2></a>
</body>
</html>
package cn.timber.servlet;
import cn.timber.mysql.HkMysql;
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 javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet("/heroServlet")
public class HeroServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//获取选择败类的String数组
String[] bailei = request.getParameterValues("bailei");
HttpSession session=request.getSession();
String username = (String)session.getAttribute("username");
System.out.println(username);
//转发到jsp
// request.getAttribute("name", username);
request.setAttribute("loginname" , username);
request.setAttribute("s" , bailei);
request.getRequestDispatcher("hero.jsp").forward(request , response);
}
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request , response);
}
}
++这里的“bailei”由于是多选项,所以一定要用getParameterValues方法来获取并用String[] 来接收,否则会出错++
关于用户名的获取由于loginServlet生命周期已结束,这里我用的session.getAttribute("username")方法来获取的,若有更好的实现方法,欢迎您的指教
<%--
Created by IntelliJ IDEA.
User: Timber
Date: 2020/12/11
Time: 9:48
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>选择结果页面</title>
</head>
<body>
欢迎您:<br>
<font color="red" size="22">
<%
String loginname = (String)request.getAttribute("loginname");
out.print(loginname);
%>
</font>
发现了混入革命队伍的败类:<br>
<%
String [] s1 = (String [])request.getAttribute("s");
for (String s : s1) {
out.print(s + "<br>");
}
%>
</body>
</html>