package web.util;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class UserLoadFilter implements Filter {

	@Override
	public void destroy() {
		// TODO Auto-generated method stub

	}
	
	
	
	@Override
	public void doFilter(ServletRequest arg0, ServletResponse arg1,
			FilterChain arg2) throws IOException, ServletException {
		HttpServletRequest hRequest = (HttpServletRequest) arg0;
		HttpServletResponse hResponse = (HttpServletResponse) arg1;
		HttpSession session = hRequest.getSession();
		String isLogin = "";
		try {
			isLogin = (String) arg0.getAttribute("isLogin");
			session.removeAttribute("isLogin");//clear session property:isLogin
			session.invalidate();// session invalidate 會話失效
			
			System.out.print(isLogin);
			if (isLogin != null && isLogin.equals("true")) {
				System.out.println("在LoginFilter中驗證通過");
				// 驗證成功，繼續處理
				arg2.doFilter(arg0,arg1);
			} else {
				// 驗證不成功，讓用戶登錄。
				hResponse.sendRedirect(hRequest.getContextPath()+"/"+"index.jsp");
				System.out.println("被LoginFilter攔截一個未認證的請求");
			}
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	@Override
	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub

	}

}