实验七 Spring MVC 应用

1、使用 Spring MVC 框架实现用户登录功能，登录成功后显示当前用户的信息；如果登录失败则显示登录失败的页面。
2、使用 Spring MVC 的数据绑定将输入的用户名和密码封装成一个类在服务端进行处理。 
3、使用拦截器实现只有登录成功的用户才能访问某些特定的页面，如果非登录成功则提示相应的错误信息。
实现界面：

目录：

UserController.java

package controller;
import javax.servlet.http.HttpSession;
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 po.User;
@Controller
public class UserController {
	@RequestMapping(value = "/login", method = RequestMethod.GET)
	public String toLogin() {
		return "login";
	}
	@RequestMapping(value = "/login", method = RequestMethod.POST)
	public String login(User user, Model model, HttpSession session) {
		String username = user.getUsername();
		String password = user.getPassword();
		if (username != null && username.equals("lisi") && password != null && password.equals("123456")) {
			session.setAttribute("USER_SESSION", user);
			return "redirect:main";
		}
		return "failure";
	}
	@RequestMapping(value = "/main")
	public String toMain() {
		return "main";
	}
	@RequestMapping(value = "/logout")
	public String logout(HttpSession session) {
		session.invalidate();
		return "redirect:login";
	}
}

LoginInterceptor.java

package interceptor;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import po.User;

public class LoginInterceptor implements HandlerInterceptor {

	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
		// TODO Auto-generated method stub
		String url = request.getRequestURI();
//		if (url.indexOf("/login") >= 0) {
		if (url.toLowerCase().endsWith("/login")) {
			return true;
		}
		HttpSession session = request.getSession();
		User user=null;
		user = (User) session.getAttribute("USER_SESSION");
		if (user != null) {
			return true;
		}
		request.setAttribute("msg", "您还有没有登录，请先登录");
		RequestDispatcher rDispatcher=request.getRequestDispatcher("WEB-INF/jsp/login.jsp");
		try {
			rDispatcher.forward(request, response);
		} catch (ServletException | IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return false;
	}
	@Override
	public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			ModelAndView modelAndView) {
		// TODO Auto-generated method stub
	}
	@Override
	public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,
			Exception ex) {
		// TODO Auto-generated method stub
	}
}

User.java

package po;

public class User {
	private Integer id;
	private String username;
	private String password;

	public Integer getId() {
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}
	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;
	}

}

failure.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>







登陆失败

重新登陆

login.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" isELIgnored="false"%>







${msg}

		用户名
 
		密码

			
	

main.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" isELIgnored="false"%>







欢迎:${USER_SESSION.username}
退出

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" isELIgnored="false"%>







欢迎:${USER_SESSION.username}
退出

web.xml

  ch9
  
    index.html
    index.htm
    index.jsp
    default.html
    default.htm
    default.jsp
  
  
    springmvc
    org.springframework.web.servlet.DispatcherServlet
    1
  
  
    springmvc
    /
  
  
    CharacterEncodingFilter
    org.springframework.web.filter.CharacterEncodingFilter
    
      encoding
      utf-8
    
  
  
    CharacterEncodingFilter
    /*
  

springmvc-servlet.xml