WAS의 서블릿이나 JSP가 요청을 받은 후 그 요청을 처리하다가, 추가적인 처리를 같은 웹 어플리케이션안에 포함된 다른 서블릿이나 JSP에게 위임하는 경우가 있습니다.
이렇게 위임하는 것을 포워드(forward)라고 합니다.
이번 시간엔 이러한 포워드에 대해서 좀 더 자세히 알아보도록 하겠습니다.
FrontServelet.java
package examples;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class FrontServlet
*/
@WebServlet("/front")
public class FrontServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public FrontServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
*/
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int diceValue = (int)(Math.random() * 6) + 1;
request.setAttribute("dice", diceValue);
RequestDispatcher requestDispatehcer = request.getRequestDispatcher("/next");
requestDispatehcer.forward(request, response);
}
}
NextSevlet.java
package examples;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class ForwardServlet
*/
@WebServlet("/forward")
public class ForwardServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public ForwardServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
*/
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head><title>form</title></head>");
out.println("<body>");
int dice = (Integer)request.getAttribute("dice");
out.println("dice : " + dice);
for(int i = 0; i < dice; i++) {
out.print("<br>hello");
}
out.println("</body>");
out.println("</html>");
}
}