[Servlet] HttpServletResponse

HttpServletResponse 역할

HTTP 응답 메시지 생성

• HTTP 응답코드 지정
• 헤더 생성
• 바디 생성

편의 기능 제공

• Content-Type, 쿠키, Redirect

HttpServletResponse 기본 사용법

//[status-line]
response.setStatus(HttpServletResponse.SC_OK);  // 200

//[response-headers]
// Content-Type: text/plain;charset=utf-8

//response.setHeader("Content-Type", "text/plain;charset=utf-8");
response.setContentType("text/plain");
response.setCharacterEncoding("utf-8");

response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
response.setHeader("Pragma", "no-cache");
response.setHeader("my-header", "hello");

//[Header 편의 메서드]
cookie(response);
redirect(response);

//[message body]
PrintWriter writer = response.getWriter();
writer.println("ok");

---

쿠키 편의 메서드

private void cookie(HttpServletResponse response) {
    //Set-Cookie: myCookie=good; Max-Age=600;
    //response.setHeader("Set-Cookie", "myCookie=good; Max-Age=600");
    Cookie cookie = new Cookie("myCookie", "good");
    cookie.setMaxAge(600); //600초
    response.addCookie(cookie);
}

---

redirect 편의 메서드

private void redirect(HttpServletResponse response) throws IOException {
    //Status Code 302
    //Location: /basic/hello-form.html
    //response.setStatus(HttpServletResponse.SC_FOUND); //302
    //response.setHeader("Location", "/basic/hello-form.html");
    response.sendRedirect("/basic/hello-form.html");
}

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