package org.javaee7.servlet.async;
import java.io.IOException;
import java.io.PrintWriter;
import javax.annotation.Resource;
import javax.enterprise.concurrent.ManagedExecutorService;
import javax.servlet.AsyncContext;
import javax.servlet.AsyncEvent;
import javax.servlet.AsyncListener;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @author Arun Gupta
*/
@WebServlet(urlPatterns = "/MyAsyncServlet", asyncSupported = true)
public class MyAsyncServlet extends HttpServlet {
// @Resource(lookup="java:comp/DefaultManagedExecutorService")
@Resource
ManagedExecutorService executor;
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code>
* methods.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
try (final PrintWriter out = response.getWriter()) {
out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<title>Async Servlet</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Async Servlet</h1>");
AsyncContext ac = request.startAsync();
ac.addListener(new AsyncListener() {
@Override
public void onComplete(AsyncEvent event) throws IOException {
System.out.println("onComplete");
}
@Override
public void onTimeout(AsyncEvent event) throws IOException {
System.out.println("onTimeout");
}
@Override
public void onError(AsyncEvent event) throws IOException {
System.out.println("onError");
}
@Override
public void onStartAsync(AsyncEvent event) throws IOException {
System.out.println("onStartAsync");
}
});
executor.submit(new MyAsyncService(ac));
out.println("Check \"server.log\" for output from Async Servlet");
out.println("</body>");
out.println("</html>");
}
}
class MyAsyncService implements Runnable {
AsyncContext ac;
public MyAsyncService(AsyncContext ac) {
this.ac = ac;
}
@Override
public void run() {
System.out.println("Running inside MyAsyncService");
ac.complete();
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
*
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}