JavaWeb_(Struts2框架)使用Struts框架实现用户的登陆 传送门
JavaWeb_(Struts2框架)Servlet与Struts区别 传送门
MySQL数据库中存在Gary用户，密码为123；第一次登陆时输入错误的密码1234后页面重定向，并输出错误的提示信息，第二次登陆时输入正确的密码，页面跳转到index.jsp中
c3p0-config.xml链接本地数据库
<?xml version="1.0" encoding="UTF-8"?>
<c3p0-config> <default-config>
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql:///strutstest</property>
<property name="user">root</property>
<property name="password">123456</property>
<property name="initialPoolSize">5</property>
<property name="maxPoolSize">20</property>
</default-config> <named-config name="oracel">
<property name="driverClass">oracle.jdbc.driver.OracleDriver</property>
<property name="jdbcUrl">jdbc:oracle:thin:@//192.168.40.128/orcl</property>
<property name="user">scott</property>
<property name="password">scott</property>
</named-config></c3p0-config>
c3p0-config.xml
package com.Gary.web;import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.sql.SQLException;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 org.apache.commons.beanutils.BeanUtils;import com.Gary.domain.User;
import com.Gary.service.UserService;@WebServlet("/login")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L; public LoginServlet() {
super();
// TODO Auto-generated constructor stub
} protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
User user = new User();
//封装user对象
try {
BeanUtils.populate(user, request.getParameterMap());
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
UserService userService = new UserService();
//传递数据，判断数据库是否有user
boolean success = false;
try {
success = userService.findUser(user);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} if(success) {
//存在用户，登陆成功重定向到index.html
response.sendRedirect(request.getContextPath()+"/index.html");
}else {
request.setAttribute("error", "用户名或密码错误！！");
//不存在,转发到login.jsp
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
} protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response);
}}
LoginServlet.java
package com.Gary.web;import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.sql.SQLException;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 org.apache.commons.beanutils.BeanUtils;import com.Gary.domain.User;
import com.Gary.service.UserService;@WebServlet("/login")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L; public LoginServlet() {
super();
// TODO Auto-generated constructor stub
} protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
User user = new User();
//封装user对象
try {
BeanUtils.populate(user, request.getParameterMap());
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
UserService userService = new UserService();
//传递数据，判断数据库是否有user
boolean success = false;
try {
success = userService.findUser(user);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} if(success) {
//存在用户，登陆成功重定向到index.html
response.sendRedirect(request.getContextPath()+"/index.html");
}else {
request.setAttribute("error", "用户名或密码错误！！");
//不存在,转发到login.jsp
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
} protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response);
}}
UserService.java
package com.Gary.domain;public class User { private String username;
private String password; public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}}
User.java
package com.Gary.dao;import java.sql.SQLException;import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;import com.Gary.domain.User;
import com.yl.lain.utils.C3p0DataSourceUtils;public class UserDao { public User findUser(User user) throws SQLException { QueryRunner runner = new QueryRunner(C3p0DataSourceUtils.getDataSource());
String sql = "select * from user where username = ? and password = ?";
return runner.query(sql, new BeanHandler<User>(User.class),user.getUsername(),user.getPassword()); }}
UserDao.java
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html><head>
<meta charset="UTF-8"><link rel="stylesheet" href="css/head.css" rel="external nofollow" />
<link rel="stylesheet" type="text/css" href="css/login.css" rel="external nofollow" />
</head><body>
<div class="dvhead">
<div class="dvlogo">
<a href="index.html" rel="external nofollow" >你问我答</a>
</div>
<div class="dvsearch">10秒钟注册账号，找到你的同学</div>
<div class="dvreg">
已有账号，立即 <a href="login.html" rel="external nofollow" >登录</a>
</div>
</div>
<section class="sec">
<form action="${pageContext.request.contextPath }/login" method="post">
<div class="register-box">
<label for="username" class="username_label"> 用 户 名 <input maxlength="20" name="username" type="text" placeholder="您的用户名和登录名" />
</label>
<div class="tips"></div>
</div>
<div class="register-box">
<label for="username" class="other_label"> 设 置 密 码 <input maxlength="20" type="password" name="password" placeholder="建议至少使用两种字符组合" />
</label>
<div class="tips"></div>
</div>
<div class="arguement">
<input type="checkbox" id="xieyi" /> 阅读并同意 <a href="javascript:void(0)" rel="external nofollow" rel="external nofollow" >《你问我答用户注册协议》</a> <a href="register.html" rel="external nofollow" rel="external nofollow" >没有账号,立即注册</a>
<div class="tips" style="color: red">${error }</div>
</div>
<div class="submit_btn">
<button type="submit" id="submit_btn">立 即 登录</button>
</div>
</form>
</section>
<script src="js/index.js" type="text/javascript" charset="utf-8"></script>
</body>
login.jsp
项目结构
数据库中用户数据
实现过程
通过c3p0-config.xml链接本地数据库
<property name="driverClass">com.mysql.jdbc.Driver</property>
<property name="jdbcUrl">jdbc:mysql:///strutstest</property>
<property name="user">root</property>
<property name="password">123456</property>
web层接受由login.jsp页面的表单/login请求
<form action="${pageContext.request.contextPath }/login" method="post">
<div class="register-box">
<label for="username" class="username_label"> 用 户 名 <input maxlength="20" name="username" type="text" placeholder="您的用户名和登录名" />
</label>
<div class="tips"></div>
</div>
<div class="register-box">
<label for="username" class="other_label"> 设 置 密 码 <input maxlength="20" type="password" name="password" placeholder="建议至少使用两种字符组合" />
</label>
<div class="tips"></div>
</div>
<div class="arguement">
<input type="checkbox" id="xieyi" /> 阅读并同意 <a href="javascript:void(0)" rel="external nofollow" rel="external nofollow" >《你问我答用户注册协议》</a> <a href="register.html" rel="external nofollow" rel="external nofollow" >没有账号,立即注册</a>
<div class="tips" style="color: red">${error }</div>
</div>
<div class="submit_btn">
<button type="submit" id="submit_btn">立 即 登录</button>
</div>
</form>
在domain层中创建用户User实体
private String username;
private String password;
package com.Gary.domain;public class User { private String username;
private String password; public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}}
User.java
web层LoginServlet.java处理用户登陆逻辑,由servlet层去调用dao层返回数据库中查询用户信息
public User findUser(User user) throws SQLException { QueryRunner runner = new QueryRunner(C3p0DataSourceUtils.getDataSource());
String sql = "select * from user where username = ? and password = ?";
return runner.query(sql, new BeanHandler<User>(User.class),user.getUsername(),user.getPassword()); }
dao层得到用户信息后传递给servlet层，servlet层获得user对象后传递给web层
web层中判断是否有用户信息，如果有，那么用户登陆成功后将页面重定向到index.html，否则跳转到login.jsp并显示错误的提示信息(将error封装到request域中在login.jsp中使用${error}标签将信息提示出来)
web层接受到login的dopost请求后调用doGet请求的逻辑处理
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
User user = new User();
//封装user对象
try {
BeanUtils.populate(user, request.getParameterMap());
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
UserService userService = new UserService();
//传递数据，判断数据库是否有user
boolean success = false;
try {
success = userService.findUser(user);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} if(success) {
//存在用户，登陆成功重定向到index.html
response.sendRedirect(request.getContextPath()+"/index.html");
}else {
request.setAttribute("error", "用户名或密码错误！！");
//不存在,转发到login.jsp
request.getRequestDispatcher("/login.jsp").forward(request, response);
}
}
