Jsp+Servlet实现简单登录注册查询
本文实例为大家分享了jsp+servlet实现简单登录注册查询的具体代码,供大家参考,具体内容如下
1、注册功能:
制作一个注册页面
用户输入:
用户名
密码
年龄
注册成功:——>跳转至登录页面进行登录
注册失败:——>文字或其他形式的提示皆可
2、简易查询:
制作一个查询页面
输入用户名
显示该用户的用户名、密码、年龄
演示
1.启动进入登陆页面
2.点击注册,进入注册页面,成功跳转到登录页面
失败则提示
回到登录页面,登录成功进入查询页面
登录失败显示提示信息
输入用户名->显示该用户的用户名、密码、年龄
代码
dao
public class userdao { private connection conn = null; private preparedstatement ps=null; private int result=0; private resultset rs=null; //用户注册 public int register(user user){ string sql="insert into users(name,password,age) value (?,?,?)"; try { //获取数据库连接对象 conn= jdbcutil.getconnection(); //获取数据库操作对象 ps=conn.preparestatement(sql); ps.setstring(1,user.getname()); ps.setstring(2,user.getpassword()); ps.setint(3,user.getage()); //执行sql result=ps.executeupdate(); } catch (exception e) { e.printstacktrace(); }finally { jdbcutil.close(null,ps,conn); } return result; } //登录验证用户信息 public int login(string username,string password){ string sql ="select count(*) from users where name=? and password=?"; try { conn=jdbcutil.getconnection(); ps=conn.preparestatement(sql); ps.setstring(1,username); ps.setstring(2,password); rs=ps.executequery(); while (rs.next()){ result=rs.getint("count(*)"); } } catch (exception e) { e.printstacktrace(); } finally { jdbcutil.close(rs,ps,conn); } return result; } //根据用户名 显示用户名、密码、年龄 public user findbyname(string username){ string sql="select name,password,age from users where name=?"; user user = null; try { conn=jdbcutil.getconnection(); ps=conn.preparestatement(sql); ps.setstring(1,username); rs=ps.executequery(); while (rs.next()){ string name = rs.getstring("name"); string password = rs.getstring("password"); int age = rs.getint("age"); user = new user(name,password,age); } } catch (exception e) { e.printstacktrace(); }finally { jdbcutil.close(null,ps,conn); } return user; } }
entity 实体类
public class user { private int id; private string name; private string password; private int age; //set... //get... //constructor... }
service
public class userserviceimpl implements userservice { userdao userdao = new userdao(); // 注册 @override public int register(user user) { return userdao.register(user); } // 登陆 @override public int login(string username, string password) { return userdao.login(username,password); } // 根据用户名查找信息 @override public user findbyname(string username) { return userdao.findbyname(username); } }
servlet
// findbynameservlet public class findbynameservlet extends httpservlet { protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { string name = request.getparameter("name"); userservice userservice = new userserviceimpl(); user user = userservice.findbyname(name); //将查询结果放入request作用域 request.setattribute("userinfo",user); request.getrequestdispatcher("/jsp/index.jsp").forward(request,response); } } // loginservlet public class loginservlet extends httpservlet { protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { //1 获取 string username = request.getparameter("username"); string password = request.getparameter("password"); //2 service调用dao对数据库操作 userservice userservice = new userserviceimpl(); int result = userservice.login(username, password); //3 成功跳转到查询页面,失败跳转到失败页面 if (result>0){ response.sendredirect("/jsp/index.jsp"); }else{ response.sendredirect("/login_error.html"); } } } // registerservlet public class registerservlet extends httpservlet { protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception { userservice userservice = new userserviceimpl(); user user = null; int result = 0; //1【调用请求对象】读取【请求头】参数信息,得到用户注册信息 string username, password, age; username = request.getparameter("username"); password = request.getparameter("password"); age = request.getparameter("age"); user = new user(username, password, integer.valueof(age)); //2 调用userservice——>userdao // 先查询用户是否存在 user byname = userservice.findbyname(username); if (byname!=null){ request.setattribute("info","用户已存在!"); request.getrequestdispatcher("/jsp/register.jsp").forward(request,response); } // 注册 result = userservice.register(user); //3 设置编码格式,防止乱码 response.setcontenttype("text/html;charset=utf-8"); printwriter out = response.getwriter(); //注册成功:——>跳转至登录页面进行登录 //注册失败:——>注册页面提示:注册失败 if (result == 1) { response.sendredirect("/login.html"); } else { request.setattribute("info","注册失败!"); request.getrequestdispatcher("/jsp/register.jsp").forward(request,response); } } }
jdbcutil
public class jdbcutil { private jdbcutil(){} //静态代码块在类加载时执行,并且执行一次。 static{ try { class.forname("com.mysql.cj.jdbc.driver"); } catch (classnotfoundexception e) { e.printstacktrace(); } } //获取数据库连接对象 public static connection getconnection() throws exception{ string url="jdbc:mysql://127.0.0.1:3306/zy?&usessl=false&servertimezone=utc&rewritebatchedstatements=true"; string user="root"; string password="rootroot"; return drivermanager.getconnection(url,user,password); } /** *关闭资源 * @param conn 连接对象 * @param ps 数据库操作对象 * @param rs 结果集 */ public static void close(resultset rs, statement ps, connection conn){ if (rs != null) { try { rs.close(); } catch (sqlexception e) { e.printstacktrace(); } } if (ps != null) { try { ps.close(); } catch (sqlexception e) { e.printstacktrace(); } } if (conn != null) { try { conn.close(); } catch (sqlexception e) { e.printstacktrace(); } } } }
index.jsp
<%@ page import="entity.user" %> <%@ page contenttype="text/html;charset=utf-8" language="java" %> 查询页面输入用户名,查询信息 <% user userinfo = (user) request.getattribute("userinfo"); %> <% if (userinfo != null) { %>
<% } %>
用户名 密码 年龄 <%=userinfo.getname()%> <%=userinfo.getpassword()%> <%=userinfo.getage()%>
register.jsp
<%@ page import="com.mysql.cj.util.stringutils" %> <%@ page contenttype="text/html;charset=utf-8" language="java" %> title <% string info =(string) request.getattribute("info"); %> <% if (!stringutils.isnullorempty(info)){ %><%=info%>
<% } %>
用户名 密码 年龄
web.xml
loginservlet servlet.loginservlet registerservlet servlet.registerservlet findbynameservlet servlet.findbynameservlet loginservlet /login registerservlet /register findbynameservlet /findbyname login.html