Back/Servlet
쿠키와 세션 - 세션을 이용한 로그인/로그아웃 기능
Hyeon_
2021. 12. 30. 23:16
쿠키와 세션 - 세션을 이용한 로그인/로그아웃 기능
예제
- sessionLogin.html
- LoginLogout.java
- SessionLogout.java
sessionLogin.html
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>로그인 창</title>
</head>
<body>
<form name="frmLogin" method="post" action="logInOut" >
아이디 :<input type="text" name="user_id"><br>
비밀번호:<input type="password" name="user_pw" ><br>
<input type="submit" value="로그인"> <input type="reset" value="다시입력">
</form>
</body>
</html>LoginLogout
@WebServlet(name = "LoginLogout", value = "/logInOut")
public class LoginLogout extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doProcess(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doProcess(request, response);
}
protected void doProcess(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession();
String user_id = request.getParameter("user_id");
String user_pw = request.getParameter("user_pw");
// 처음 접속이면
if(session.isNew()) {
// user_id 입력 값이 있으면
if(user_id != null) {
// SID 이름, user_id 값으로 세션 변수 설정
session.setAttribute("SID", user_id);
// 다시 실행시켜서 SID 확인
out.print("<a href='logInOut'>로그인 상태 확인</a>");
}else { // user_id 입력 값이 없으면
out.print("<a href='sessionLogin.html'>다시 로그인 하세요!</a>");
session.invalidate();
}
} else { //아니고 세션이 있으면
user_id = (String) session.getAttribute("SID");
if(user_id != null && user_id.length() != 0) {
out.print("안녕하세요 " + user_id + "님!!");
out.print("<br><a href='logout'>로그아웃</a>");
} else {
out.print("<a href='sessionLogin.html'>다시 로그인 하세요!</a>");
session.invalidate();
}
}
}
}SessionLogout
@WebServlet(name = "SessionLogout", value = "/logout")
public class SessionLogout extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
HttpSession session = request.getSession();
session.invalidate(); // 세션 무효화
out.print("로그아웃 되었습니다. <br>");
out.print("<a href='sessionLogin.html'>로그인</a>");
}
}