package com.hmkcode;
import java.io.IOException;
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;
@WebServlet(name="asyncServlet",value = {"/async"},asyncSupported = true)
public class AsyncServlet extends HttpServlet
{
private static final long serialVersionUID = 1L;
String param ="";
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
// 1.0 start async
final AsyncContext ctx = req.startAsync();
param = ctx.getRequest().getParameter("seq");
// 2.0 set the timeout
ctx.setTimeout(0);
// 3.0 add listener
ctx.addListener(new AsyncListener() {
@Override
public void onTimeout(AsyncEvent arg0) throws IOException {
System.out.println("onTimeout...");
}
@Override
public void onStartAsync(AsyncEvent arg0) throws IOException {
System.out.println("onStartAsync...");
}
@Override
public void onError(AsyncEvent arg0) throws IOException {
System.out.println("onError...");
}
@Override
public void onComplete(AsyncEvent arg0) throws IOException {
System.out.println("onComplete...");
}
});
// 4.0 run a thread
ctx.start(new Runnable() {
@Override
public void run() {
try {
// hold until receive exit
while(!param.equals("exit")){}
ctx.getResponse().getWriter().write(ctx.getRequest().getParameter("seq"));
} catch (IOException e) {
e.printStackTrace();
}
ctx.complete();
}
});
}
}