web第三节课作业

2019-11-06 08:00:22

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来源：转载

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这节课是实现什么？

User.java 用户对象UserDao.java 数据流UserServlet.java 调用servletweb.xml 配置文件index.jsp 网页编辑

项目文件

这里写图片描述

1.User.java—>建立User对象并配上set get hashcode

在User内编写PRivate数据 username、passWord

并且设置set get hashcode equals 方法

代码如下：

package com.zking.bean;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; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((password == null) ? 0 : password.hashCode()); result = prime * result + ((username == null) ? 0 : username.hashCode()); return result; } @Override //equals判断username and password 是否相同相同的话就不能登录 public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; User other = (User) obj; if (password == null) { if (other.password != null) return false; } else if (!password.equals(other.password)) return false; if (username == null) { if (other.username != null) return false; } else if (!username.equals(other.username)) return false; return true; }}

2.UserDao.java

package com.zking.dao;import com.zking.bean.User;public class UserDao { public boolean login(User user){ User u = new User(); u.setUsername("123"); u.setPassword("xiekun"); //只有正确的输入用户名：123，密码:xiekun 才能登陆成功 return u.equals(user); }}

3.UserServlet.java–>调用servlet

package com.zking.action;import com.zking.bean.User;import com.zking.dao.UserDao;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@SuppressWarnings("serial")public class UserServlet extends HttpServlet{ public void service (HttpServletRequest request, HttpServletResponse response) throws IOException,ServletException{ response.setCharacterEncoding("UTF-8"); response.setContentType("text/html"); PrintWriter out = response.getWriter(); //获得URL地址 StringBuffer str = request.getRequestURL(); //out.println(str+" "); //out print ----> http://localhost:8899/testweb/login.action //截取路径 path = login String path = str.substring(str.lastIndexOf("/")+1, str.lastIndexOf(".")); //点击登录即可输出path System.out.println(path); if("login".equals(path)){ //username and password was writtern in username and pwd String username = request.getParameter("username"); String pwd = request.getParameter("password"); User u = new User(); u.setUsername(username); u.setPassword(pwd); UserDao ud = new UserDao(); boolean flag = ud.login(u); if(flag){ out.println("登陆成功！"); }else{ out.println("用户名或者密码错误！"); } } else if("register".equals(path)){ }else{ out.println("bilibili"); } }}

4.web.xml—>配置servlet部分

<servlet> <servlet-name>login</servlet-name> <servlet-class>com.zking.action.UserServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>login</servlet-name> <url-pattern>/login.action</url-pattern> </servlet-mapping>

5. index.jsp–>网页显示部分

<html> <head> <title>login in</title> </head> <body> <form action="/testweb/login.action"> <table> <tr align="center"> <td colspan ="4" style = "color:red;"><h1>login  in</h1></td> </tr> <tr> <td ><label for="uname">user:</label></td> <td colspan ="3"><input typle ="text" id="uname" name="username" value="QQ/email/phone"></td> </tr> <tr> <td ><label for="upassword">password:</label></td> <td colspan ="3"><input typle ="text" id="upassword" name="password" ></td> </tr> <tr align="center"> <td colspan ="4"><input type="submit" value="login o"></td> </tr> </table> </form> </body></html>

这里写图片描述

新手学习中，如有错误，烦请斧正！

http://localhost:8899/testweb 可以跳到登录界面 http://localhost:8899/testweb/login.action 可以跳入点击后的界面，不过登录失败http://localhost:8899/testweb/login.action?username=123&password=xiekun 可以登陆成功

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