- HttpServletResponse 기본 사용법
- HTTP 응답 메시지 생성하는 역할
- 헤더 생성
- 바디 생성
- 편의 기능제공 : ContentType 헤더를 편리하게 지정, 쿠키 편리하게 생성, Redirect
package hello.servlet.basic.response;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
@WebServlet(name = "responseHeaderServlet", urlPatterns="/response-header")
public class ResponseHeaderServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//[status-line]
response.setStatus(HttpServletResponse.SC_OK);
//[response-headers]
// response.setHeader("Content-Type", "text/utf-8");
// response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate");
// response.setHeader("Pragma", "no-cache");
// response.setHeader("my-Header", "hello");
PrintWriter writer = response.getWriter();
writer.println("ok");
}
//아래 두 문장이 위의 setHeader를 대신해줌
private void content(HttpServletResponse response){
//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.setContentTypeLength(2); //생략 시 자동 생성
//
}
}
- 쿠키 : 쿠키 객체를 만들어서 response.addCookie 하면 가능
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("my-Cookie", "good");
cookie.setMaxAge(600);
response.addCookie(cookie);
}- redirect를 위한 편의 메서드
private void redirect(HttpServletResponse response){
//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");
}
- HTTP응답 데이터 - 단순 텍스트, HTML
- 단순 텍스트, HTML, HTTP API로 응답
- 이 중 HTML을 살펴볼 예정
- 코드
@WebServlet(name = "responseHtmlServlet", urlPatterns = "/response-html")
public class ResponseHtmlServlet extends HttpServlet {
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.setContentType("text/html");
resp.setCharacterEncoding("utf-8");
PrintWriter writer = resp.getWriter();
writer.println("<html>");
writer.println("<body>>");
writer.println("<div>ㅎㅇ </div>");
writer.println("</body>");
writer.println("</html>");
}
