🔷 HttpServletResponse역할
🔹1. 응답메시지 생성
🔸 HTTP응답코드 지정
response.setStatus(HttpServletResponse.SC_OK); response.setStatus(HttpServletResponse.SC_BAD_REQUEST);
🔸 헤더 생성
response.setHeader("Content-Type", "text/plain;charset=utf-8"); // 캐쉬무효화 : 캐쉬 없애는 세팅 response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); response.setHeader("Pragma", "no-cache"); // 내가 원하는 임의의 헤더 만들기 response.setHeader("my-header", "hello");
🔸 바디 생성
PrintWriter writer = response.getWriter(); writer.println("OK");
🔹2. 편의 기능 제공
🔸 Content-Type
//Content-Type: text/plain;charset=utf-8 //Content-length: 2 // response.setHeader("Content-Type", "text/plain;charset=utf-8"); response.setContentType("text/plain"); response.setCharacterEncoding("utf-8"); // response.setContentLength(2); // 생략시 자동 생성
🔸 쿠키
//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); response.addCookie(cookie);
🔸 Redirect
//Status Code 302 //Location: /basic/hello-form.html // response.setStatus(HttpServletResponse.SC_FOUND); // response.setHeader("Location", "/basic/hello-form.html"); response.sendRedirect("/basic/hello-form.html");
🔷2. 응답데이터(html/text)
@Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // Content-Type: text/html;charset=utf-8 response.setContentType("text/html"); response.setCharacterEncoding("utf-8"); PrintWriter writer = response.getWriter(); writer.println("<html>"); writer.println("<body>"); writer.println("<div>안녕!!</div>"); writer.println("</body>"); writer.println("</html>"); }PrintWriter writer = response.getWriter(); writer.println("OK");
🔷3. 응답데이터(json)
private ObjectMapper objectMapper = new ObjectMapper(); @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //Content-Type: application/json response.setContentType("application/json"); response.setCharacterEncoding("utf-8"); HelloData hellodata = new HelloData(); hellodata.setUsername("CHO"); hellodata.setAge(10); //json형식으로 바꾸기 {"username":"CHO", "age":10} String result = objectMapper.writeValueAsString(hellodata); response.getWriter().write(result);
백견이 불여일타