package com.example;

import java.io.File;
import java.io.IOException;

import javax.servlet.AsyncContext;
import javax.servlet.AsyncEvent;
import javax.servlet.AsyncListener;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.catalina.Context;
import org.apache.catalina.startup.Tomcat;
import org.apache.tomcat.util.descriptor.web.ErrorPage;

public class TomcatAsyncTimeoutClientAbortException {

	public static void main(String[] args) throws Exception {
		Tomcat tomcat = new Tomcat();
		tomcat.setPort(8080);
		Context context = tomcat.addContext("",
				new File(System.getProperty("java.io.tmpdir")).getAbsolutePath());
		tomcat.addServlet("", "timeout", AsyncServlet.class.getName())
				.setAsyncSupported(true);
		tomcat.addServlet("", "error", ErrorServlet.class.getName());
		context.addServletMapping("/timeout", "timeout");
		context.addServletMapping("/error", "error");
		ErrorPage errorPage = new ErrorPage();
		errorPage.setLocation("/error");
		context.addErrorPage(errorPage);
		tomcat.start();
		while (true) {
			Thread.sleep(1000);
		}
	}

	public static class AsyncServlet extends HttpServlet {

		@Override
		protected void doGet(HttpServletRequest req, HttpServletResponse resp)
				throws ServletException, IOException {
			if (req.getAttribute("timeout") != null) {
				resp.sendError(503);
			}
			else {
				final AsyncContext context = req.startAsync();
				context.setTimeout(5000);
				context.addListener(new AsyncListener() {

					@Override
					public void onTimeout(AsyncEvent event) throws IOException {
						HttpServletResponse response = (HttpServletResponse) event
								.getSuppliedResponse();
						if (!response.isCommitted()) {
							((HttpServletRequest) event.getSuppliedRequest())
									.setAttribute("timeout", true);
							context.dispatch();
						}
					}

					@Override
					public void onStartAsync(AsyncEvent event) throws IOException {
					}

					@Override
					public void onError(AsyncEvent event) throws IOException {
					}

					@Override
					public void onComplete(AsyncEvent event) throws IOException {
					}
				});
			}
		}

	}

	public static class ErrorServlet extends HttpServlet {

		@Override
		protected void doGet(HttpServletRequest req, HttpServletResponse resp)
				throws ServletException, IOException {
			resp.getWriter().println("Error!");
			resp.flushBuffer();
		}

	}

}