/**
* Caso o response ja esteja fechado ou o metodo startAsync() ja tenha sido chamado, uma nova
* invocacao resultara em uma IllegalStateException.
*/
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
PrintWriter writer = resp.getWriter();
writer.println("Antes de iniciar a tarefa assincrona");
/*
* Para iniciar uma requisicao assincrona, basta chamar o metodo
* startAsync de ServletRequest. O metodo startAsync é sobrecarregado
* para receber um ServletRequest e um ServletResponse, desta forma é
* possivel passar wrappers para ele. Caso o metodo startAsync seja
* chamado, os objetos ServletRequest e Response originais serao
* utilizados.
*/
AsyncContext asyncContext = req.startAsync();
MyAsyncTask asyncTask = new MyAsyncTask(asyncContext, writer);
/*
* O tempo padrao de time out depende do container, geralmente está
* entre 5 e 10 segundos. Para desabilitar o time out basta informar um
* valor negativo ou 0. Esse metodo pode ser chamado antes ou depois do
* metodo start().
*/
asyncContext.setTimeout(-1);
/*
* A Interface AsyncContext possui metodos para configurar a tarefa
* assincrona e inicializar a mesma. O metodo estart recebe um runnable
* que sera responsavel por realizar o processamento da tarefa
* assincrona. Quando esse metodo é chamado, o processamento é realizado
* por outra Thread do pool de Threads do servidor.
*/
asyncContext.start(asyncTask);
/*
* Depois do start() da tarefa assincrona, o fluxo continua normalmente,
* e quando o metodo service() é encerrado, a resposta nao é commitada
* enquanto o metodo complete() de AsyncContext não for chamado. Desta
* forma, o container processa a tarefa assincrona um background em
* outra Thread.
*/
writer.println("Depois de iniciar a tarefa assincrona");
/*
* Retorna o AsyncContext inicializado para esse request. Caso o metodo
* startAsync() ainda nao tenha sido chamado, uma IllegalStateException
* ocorrera.
*/
req.getAsyncContext();
}
@Override
public Object getAsyncResult(long timeout) {
// MockHttpServletRequest type doesn't have async methods
HttpServletRequest request = this.mockRequest;
if ((timeout != 0) && request.isAsyncStarted()) {
if (timeout == -1) {
timeout = request.getAsyncContext().getTimeout();
}
if (!awaitAsyncResult(timeout)) {
throw new IllegalStateException(
"Gave up waiting on async result from handler [" + this.handler + "] to complete");
}
}
return this.asyncResult;
}
@Override
protected void doGet(final HttpServletRequest req, final HttpServletResponse resp)
throws ServletException, IOException {
result = new StringBuilder();
result.append('1');
result.append(req.isAsyncStarted());
req.startAsync();
result.append('2');
result.append(req.isAsyncStarted());
req.getAsyncContext()
.start(
new Runnable() {
@Override
public void run() {
Thread t =
new Thread(
new Runnable() {
@Override
public void run() {
try {
result.append('3');
result.append(req.isAsyncStarted());
Thread.sleep(1000);
result.append('4');
result.append(req.isAsyncStarted());
resp.setContentType("text/plain");
resp.getWriter().print("OK");
req.getAsyncContext().complete();
result.append('5');
result.append(req.isAsyncStarted());
done = true;
} catch (InterruptedException e) {
result.append(e);
} catch (IOException e) {
result.append(e);
}
}
});
t.start();
}
});
// Pointless method call so there is somewhere to put a break point
// when debugging
req.getMethod();
}
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
if (req.isAsyncStarted()) {
req.getAsyncContext().complete();
} else if (req.isAsyncSupported()) {
AsyncContext actx = req.startAsync();
actx.addListener(this);
resp.setContentType("text/plain");
clients.add(actx);
if (clientcount.incrementAndGet() == 1) {
ticker.addTickListener(this);
}
} else {
new Exception("Async Not Supported").printStackTrace();
resp.sendError(400, "Async is not supported.");
}
}
@Override
public AsyncContext getAsyncContext() {
return request.getAsyncContext();
}
/** Processes the HTTP request, */
protected void processRequest(
HttpServletRequest request, HttpServletResponse response, String request_type)
throws ServletException, IOException {
try {
// Is this a dispatch?
Object consume_status_key = request.getAttribute(AsyncServletProcessUtil.CONSUME_STATUS_KEY);
// Make a process client,
PlatformContext ctx = PlatformContextFactory.getPlatformContext();
ProcessInputMessage result;
ProcessResult result_ob;
// Is this the continuation init?
if (consume_status_key == null) {
Cookie pid_cookie = null;
// The process id cookie,
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie c : cookies) {
String cname = c.getName();
if (cname.equals("pid")) {
pid_cookie = c;
}
}
}
if (pid_cookie == null) {
// Give a friendlier error message here?
response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Session cookie not found");
return;
}
// Get the cookie's value,
String process_id_str = pid_cookie.getValue();
AppServiceProcessClient process_client = ctx.getAppServiceProcessClient();
ProcessId process_id = ProcessId.fromString(process_id_str);
String ip_addr = request.getRemoteAddr();
// Check if the process is valid,
ProcessMessage msg_to_send = ByteArrayProcessMessage.encodeArgs("?", null, null, ip_addr);
// Invoke the function on the process id,
result_ob = process_client.invokeFunction(process_id, msg_to_send, true);
request.setAttribute(getClass().getName(), result_ob);
result = result_ob.getResult(AsyncServletProcessUtil.createNotifier(request));
if (result == null) {
// Set timeout to 30 seconds,
request.getAsyncContext().setTimeout(30 * 1000);
return;
}
}
// Not initial,
else {
result_ob = (ProcessResult) request.getAttribute(getClass().getName());
result = result_ob.getResult();
}
// This would be a timeout,
if (result == null) {
response.sendError(
HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "Timed out waiting for response");
return;
}
if (result.getType() == ProcessInputMessage.Type.RETURN_EXCEPTION) {
throw new ServletException(result.getError());
}
// Ok, we now have our result from the process,
Object[] args = ByteArrayProcessMessage.decodeArgsList(result.getMessage(), 0);
String resp = (String) args[0];
if (!resp.equals("OK")) {
throw new RuntimeException("Invalid response from process: " + resp);
}
// The user of the process,
String username = (String) args[1];
// Ok, everything looks good to go,
String location;
String html_body;
// Context info,
String context_path = request.getContextPath();
if (context_path == null) context_path = "";
if (context_path.equals("/")) context_path = "";
String servlet_path = request.getServletPath();
String path_info = request.getPathInfo();
if (path_info == null) path_info = "/";
// Create the response,
DDBResourceAccess mckoi_access = ctx.getDDBResourceAccess();
// Parse the link,
StringBuilder request_link = new StringBuilder();
request_link.append(context_path);
request_link.append(servlet_path);
request_link.append(path_info);
// Sub-part,
int delim = path_info.lastIndexOf("/");
String path_p = path_info.substring(0, delim);
if (path_p.startsWith("/")) {
path_p = path_p.substring(1);
}
// 'path_p' now contains the path we are looking at,
// If no path_p,
if (path_p.equals("")) {
String link_prepend = context_path + servlet_path + "/";
location = "Path List";
html_body = pathListSummary(mckoi_access, link_prepend);
} else {
ODBTransaction t = mckoi_access.createODBTransaction(path_p);
// Extract the location,
delim = request_link.lastIndexOf("/");
location = request_link.substring(delim + 1);
String link_prepend = request_link.substring(0, delim + 1);
// Get the 'pos' and 'size' vars if they exist,
String pos = request.getParameter("pos");
String size = request.getParameter("size");
if (pos != null) {
location = location + "?pos=" + pos + "&size=" + size;
}
if (location.equals("")) {
location = "Path: " + path_p;
html_body = ODBPathSummary(t, path_p, link_prepend);
} else {
// Get the formatter,
ODBHTMLFormatter formatter = new ODBHTMLFormatter(t, link_prepend);
// Format it,
html_body = formatter.format(location);
}
}
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
out.println("<html>");
out.println("<head>");
out.println("<title>DBBrowser - " + HTMLWriter.toHTMLEntity(location) + "</title>");
out.println("<style type=\"text/css\">");
out.println(" table { border: 1px solid #000000; border-collapse: collapse; }");
out.println(
" td { border-left: 1px solid #000000; border-right: 1px solid #000000; padding: 0px 6px 0px 6px; }");
out.println(" th { background: #000000; color: #FFFFFF; }");
out.println(" table.oblist { font-family:monospace; }");
out.println(" table.data { border: none; border-collapse: collapse; }");
out.println(
" table.data td { border-left: none; border-right: none; padding: 2px 12px 2px 12px; }");
out.println("</style>");
out.println("</head>");
out.println("<body>");
out.println(html_body);
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
} catch (Throwable e) {
// Output the error message,
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
out.println("<html>");
out.println("<head>");
out.println("<title>DBBrowser - error when producing page.</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>" + HTMLWriter.toHTMLEntity(e.getMessage()) + "</h1>");
out.print("<pre>");
StringWriter str_out = new StringWriter();
PrintWriter pout = new PrintWriter(str_out);
e.printStackTrace(pout);
pout.flush();
out.print(HTMLWriter.toHTMLEntity(str_out.toString()));
out.println("</pre>");
out.println("</body>");
out.println("</html>");
} finally {
out.close();
}
}
}