案例：用户登录(html--servlet--mysql)
案例：用户登录(html–servlet–mysql)
需要用到的内容：HTML+CSS，Tomcat，Servlet，DBUtils，c3p0，MySQL
1、创建web项目student_management
1）导入jar包，放入WEB-INF下的lib文件夹中—c3p0,dbutils,mysql，
2）在src 下创建包
com.offcn.dao----放操作数据库的文件，即增删查改
com.offcn.javabean—对应数据库的实体类
com.offcn.servlet
3）c3p0的配置文件放在src下，注意其中的一些内容要根据具体数据库来修改
2、设计登录页面，WebContent下创建login.html文件
<html>
<head>
<meta charset="UTF-8">
<title>学生管理系统登录title>
<style type="text/css">
form {
width: 300px;
heigth:200px;
border:1px,solid,black;
margin:auto;
}
style>
head>
<body>
<form action="admin" method="post">
<h2>学生管理系统h2>
账号:<input type="text" name="username" /><br/>
密码：<input type="password" name="password"/><br/>
<input type="submit" value="登录">
<a href="">去注册a>
form>
body>
html>
3、创建数据库及数据表
CREATE DATABASE school;
CREATE TABLE admin (
aid INT(10) PRIMARY KEY AUTO_INCREMENT,
aname VARCHAR(20) NOT NULL,
apwd VARCHAR(20) NOT NULL
);
INSERT INTO admin VALUES(1,'JiXiang','123456');
4、在javabean包中创建Admin.java文件
package com.offcn.javabean;
public class Admin {
private int aid;
private String aname;
private String apwd;
public Admin() {
}
public Admin(int aid, String aname, String apwd) {
super();
this.aid = aid;
this.aname = aname;
this.apwd = apwd;
}
public int getAid() {
return aid;
}
public void setAid(int aid) {
this.aid = aid;
}
public String getAname() {
return aname;
}
public void setAname(String aname) {
this.aname = aname;
}
public String getApwd() {
return apwd;
}
public void setApwd(String apwd) {
this.apwd = apwd;
}
}
5、在dao包中创建AdminDao.java文件
package com.offcn.dao;
import java.sql.SQLException;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.offcn.javabean.Admin;
public class AdminDao {
public Admin getAdminByNameAndPwd(String aname,String apwd) {
Admin admin = null;
ComboPooledDataSource ds = new ComboPooledDataSource();
QueryRunner qr = new QueryRunner(ds);
String sql = "select * from admin where aname = ? and apwd = ?";
try {
admin = qr.query(sql,new BeanHandler<>(Admin.class),aname,apwd);
} catch (SQLException e) {
e.printStackTrace();
}
return admin;
}
}
6、在servlet包中创建AdminServlet.java文件
package com.offcn.servlet;
import java.io.IOException;
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 com.offcn.dao.AdminDao;
import com.offcn.javabean.Admin;
public class AdminServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public AdminServlet() {
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String aname = request.getParameter("username");
String apwd = request.getParameter("password");
AdminDao ad = new AdminDao();
Admin admin = ad.getAdminByNameAndPwd(aname, apwd);
if(admin==null) {
response.sendRedirect("login.html");
}else {
response.sendRedirect("index.html");
}
}
}
7、WebContent下创建index.html文件(此为非必要，为了第6步增设的，实际项目中另说)
<html>
<head>
<meta charset="UTF-8">
<title>Insert title heretitle>
head>
<body>
恭喜你，登录成功！
body>
html>
8、在web.xml文件中对AdminServlet.java进行配置
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
<display-name>student_managementdisplay-name>
<welcome-file-list>
<welcome-file>index.htmlwelcome-file>
<welcome-file>index.htmwelcome-file>
<welcome-file>index.jspwelcome-file>
<welcome-file>default.htmlwelcome-file>
<welcome-file>default.htmwelcome-file>
<welcome-file>default.jspwelcome-file>
welcome-file-list>
<servlet>
<servlet-name>AdminServletservlet-name>
<servlet-class>com.offcn.servlet.AdminServletservlet-class>
servlet>
<servlet-mapping>
<servlet-name>AdminServletservlet-name>
<url-pattern>/adminurl-pattern>
servlet-mapping>
web-app>