1.创建一个动态的web工程2.导入springMvc所需要的jar包(这里可以去网上找,资源有很多)前两部就不详细描述了,后面才是正经代码~首先有一个web. <servlet> <servlet-name>springmvc</servlet ...
1.创建一个动态的web工程
2.导入springMvc所需要的jar包(这里可以去网上找,资源有很多)
前两部就不详细描述了,后面才是正经代码~
首先有一个web.
<servlet> <servlet-name>springmvc</servlet-name> <servlet-class> org.springframework.web.servlet.DispatcherServlet </servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping>
加入的这个叫Dispatcher Servlet,可以根据servlet-name找到对应的小配置文件,也就是配置spring MVC的文件
在web.
<? ="http://www.w3.org/2001/ ="http://www.springframework.org/schema/p" ="http://www.springframework.org/schema/context" ="http://www.springframework.org/schema/mvc" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd"> <!--默认的注解映射的支持 --> <mvc:annotation-driven/> <!--启用自动扫描 --> <context:component-scan base-package="controller"/> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <property name="suffix" value=".jsp"/> </bean></beans>
注意说明的是,启动自动扫描,spring会在指定的包下(例如我这里是controller包),自动扫描标注@Controller的类
prefix指的是返回的值给自动加一个前缀,同理suffix指的就是后缀
看到这里也是够辛苦了,上面是给出的完整目录,下面开始写逻辑代码,先从loginController开始
@Controllerpublic class LoginController { @RequestMapping(value="/",method=RequestMethod.GET) public String sayHello(){ //model.addAttribute("msg", "Hello,World!"); return "login"; }
解释上面代码,@Controller,标注这个类是Controller类,spring会自动进行扫描,@Request Mapping中的value指的是url中的地址后缀,设置成/的目的当然是为了方便啊,
比如启动工程时,url只需要输入什么localhost:8080/项目名,它就会自动跳转到login页面;method指的是来的url是post请求还是get请求
return的是login字符串,大家还记得上面说的prefix了吧,它就会把你的url自动拼接上,完整路径就是下面这个
/WEB-INF/jsp/login.jsp
接下来看login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>login</title></head><body> <form action="login" method="post"> 用户名:<input type="text" name="username"/><br/> 密 码:<input type="password" name="password"/> <input type="submit" value="登陆"/> <a href="regist">注册</a> </form></body></html>
这里的action返回的是login,Controller会自动捕获到这个请求,于是在login Controller中要有一个方法来捕获这个请求
@RequestMapping(value="login",method=RequestMethod.POST) public String login(Model model, // 向前台页面传的值放入model中 HttpServletRequest request){ // 从前台页面取得的值 String username = request.getParameter("username"); String password = request.getParameter("password"); String user_name = LoginCheck.check(username, password); if(user_name != null && user_name != ""){ model.addAttribute("msg", user_name); return "success"; }else{ return "login2"; } }
登陆嘛,当然要有验证,于是就有了LoginCheck,不多说,上代码
package logic;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import dao.Dao;public class LoginCheck { public static String check(String username,String password){ try { Connection conn = Dao.getConnection(); PreparedStatement p = conn.prepareStatement("select * from user_t where user_name=? and password=?"); p.setString(1, username); p.setString(2, password); ResultSet rs = p.executeQuery(); if(rs.next()){ String user_name = rs.getString("user_name"); Dao.close(rs, p, conn); return user_name; } Dao.close(rs, p, conn); } catch (Exception e) { e.printStackTrace(); } return ""; }}
向数据库查询就要有DAO啦,Dao网上都有,我的就是在网上随便找一个改改就用了~
package dao;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;public class Dao { // 获取数据库连接 public static Connection getConnection(){ Connection conn = null; String url = "jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8&useSSL=false&serverTimezone=Hongkong"; try { Class.forName("com.mysql.cj.jdbc.Driver"); conn = DriverManager.getConnection(url,"root","数据库密码");//大家分享代码的时候也不要暴露自己的数据库密码,这样是非常不安全的 } catch(ClassNotFoundException e) { e.printStackTrace(); System.out.println("数据库驱动加载出错"); } catch(SQLException e) { e.printStackTrace(); System.out.println("数据库出错"); } return conn; } //关闭相关通道 public static void close(ResultSet rs,PreparedStatement p,Connection conn) { try { if(!rs.isClosed()){ rs.close(); } if(!p.isClosed()){ p.close(); } if(!conn.isClosed()){ conn.close(); } } catch(SQLException e) { e.printStackTrace(); System.out.println("数据关闭出错"); } } //关闭相关通道 public static void close(PreparedStatement p,Connection conn) { try { if(!p.isClosed()){ p.close(); } if(!conn.isClosed()){ conn.close(); } } catch(SQLException e) { e.printStackTrace(); System.out.println("数据关闭出错"); } }}
好了,如果查询的结果匹配上数据库中查询到的值了,那么就可以跳转到success页面了,success.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>登陆成功</title></head><body> 登陆成功! 欢迎~${msg};</body></html>
login大功告成,接下来的注册页面和这个道理相似,我不多废话了,把代码附上供大家参考
首先是regist.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>注册页面</title></head><body> <form action="registSuccess" method="Post"> 用户名:<input type="text" name="username"/> 密 码<input type="text" name="password"/> 年 龄<input type="number" name="age"/> <input type="submit" value="提交"/> </form></body></html>
接下来是RegistController
package controller;import javax.servlet.http.HttpServletRequest;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import logic.RegistCheck;@Controllerpublic class RegistController { @RequestMapping(value="regist",method=RequestMethod.GET) public String regist(){ return "regist"; } @RequestMapping(value="registSuccess",method=RequestMethod.POST) public String registSuccess(HttpServletRequest request,Model model){ String username = request.getParameter("username"); String password = request.getParameter("password"); String age = request.getParameter("age"); if(RegistCheck.registCheck(username, password,age)){ model.addAttribute("username", username); return "login"; }else{ return "regist2"; } }}
接下来是RegistCheck
package logic;import java.sql.Connection;import java.sql.PreparedStatement;import dao.Dao;public class RegistCheck { public static boolean registCheck(String username,String password,String age){ String user_name = LoginCheck.check(username, password); if(user_name == null || user_name == ""){ try { Connection conn = Dao.getConnection(); PreparedStatement p = conn.prepareStatement("insert user_t(user_name,password,age) VALUES (?,?,?);"); p.setString(1, username); p.setString(2, password); p.setString(3, age); p.executeUpdate(); System.out.println("注册成功"); Dao.close(p, conn); return true; } catch (Exception e) { e.printStackTrace(); } } return false; }}
还有一个registSuccess.jsp,成功返回的页面,我只是放了个空页面,没内容
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>注册成功</title></head><body> 注册成功!</body></html>
好了,现在为止login和注册页面都写好了,新人刚到公司的时候非常容易碰到这样的小练习,哈哈哈说多了,喜欢就点赞哈
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Java从学习到放弃,MySQL从删库到跑路,哈哈哈
原标题:SpringMVC demo 小例子,实现简单的登录和注册
关键词:Spring
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