I have to send a log message to a servlet and not care about it

[zooxmusic]

Hi all, this is probably a basic question but I need an answer quick and I don't know it. I have to send an xml doc to a servlet in a seperate thread for logging purposes and I don't care about it after I send it. As it is now I am sending it on an HttpUrlConnection and i have to ask for the InputStream before it actually executes the call. And then it sits and waits for the input stream to get back. I need a way to send the xml doc to the servlet and then I don't want to wait. Just move on and if it didn't get there, its not a big thing.

Brian


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[sedj]

Use a class that extends Thread, takes an outputstream or httpurlconnection or url, and the xml doc/string as a constructor parameter and fire it off : eg :

class SenderThread extends Thread {
	String szUrl;
	String szData;
	
	public SenderThread(String szUrl, String szData) {
		this.szUrl = szUrl;
		this.szData = szData;
	}
	
	public void run() {
	   try {
		URL url = new URL(szUrl);
		HttpURLConnection huc = URL.openConnection();
		... send your data ...
	   } catch (IOException ioe) {
	   	...
	   }
	}
}

// and in your client code
new SenderThread("[URL unfurl="true"]http://www.bla.com/aServlet",[/URL] "<my><data>Hello</data></my>").start();

--------------------------------------------------
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[zooxmusic]

really, I had something similar and it didn't seem to execute until I called httpUrlConnection.getInputStream()? I will try it. thanks

Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!

 

[sedj]

Hmmm, that doesn't sound quite right - if you call Thread.start() it executes a brand new thread - no waiting around - the code is detached from the parent process.

Are you sure you called the start() method, and not run() or called join() ?

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[zooxmusic]

no, no... the HttpUrlConnection doesn't actually call the "other" servlet until I explicitly call httpUrlConnection.getInputStream(). And then that calls is syncronous so it sits there and waits. The thread stuff really was extraneous info that I didn't even need to mention. I have that part of it working fine.

Brian


Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!

 

[stefanwagner]

Perhaps you may go with an UDP- instead of a TCP-connection. UDP is a connection-less protocol without errorcorrection afaik.

seeking a job as java-programmer in Berlin:

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[zooxmusic]

Hmmmm. How does that work? I can't use UDP over http can I? What classes would be involved?

Brian


Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!

 

[timw]

I think, Brian, that if you posted snippets of your code we might spot why your intial attempt failed. Sedj's suggestion seemed quite sensible to me, so maybe you've got a slight problem in how you're handling your threading.

Tim
---------------------------
"Your morbid fear of losing,
destroys the lives you're using." - Ozzy

 

[zooxmusic]

Ok,


private void call()
{
long startTime = 0;
URL url = null;
HttpURLConnection httpConnection = null;
OutputStreamWriter osw = null;

try
{

url = new URL(address);
httpConnection = (HttpURLConnection)url.openConnection();

httpConnection.setRequestMethod("POST");
httpConnection.setDoOutput(true);
httpConnection.setDoInput(false);
osw = new OutputStreamWriter(httpConnection.getOutputStream());
osw.write("xmldata=" + URLEncoder.encode(xmlString, "latin1"));
osw.flush();
osw.close();

//If I don't put this in, it never gets called
InputStream in = httpConnection.getInputStream();

}
catch(Exception e)
{
....handle exception
}

Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!

 

[sedj]

Well thats not multi-threaded is it ?!

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[zooxmusic]

I did mention that I have the tread under control.

>>The thread stuff really was extraneous info that I didn't even need to mention


I understand and have the thread working. It's not my problem.

Am I not articulating something correctly?

Brian

Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!

 

[sedj]

Well possibly, because from what can gather so far, your situation is this :

You have an application.
Within that application, you perform some process.
Part of that means sending some data to a servlet - which you want to just hand off without blocking your parent thread's execution.

You say you have the threading correct, so I don't understand your problem - so what if you have to call getInputStream() ? Who cares ? That code is within a separate thread so its not blocking your parent process.

HTTP protocol is a TWO-WAY protocol. Client sends data. Server reads data. Server sends response. Client reads response. Transaction complete. Because most HTTP servers expect to send some data back to the client, they probably block the socket IO on the network level (see native C/C++ recv() and send() calls to understand why) - which would maybe explain why you must call getInputStream().

But I fail to understand why this is an issue to you.

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[zooxmusic]

Oh, I see. It is an issue because I suppose I did "care" that I had to call getInputStream(). I see your point and understand. I will now let it go. Thank you for setting me straight.

Brian


Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!

 

[sedj]

Cool
Don't forget to close the streams and urlconnection aswell.

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[zooxmusic]

Absolutely. Preaching to the choir baby

Spend like you don't need the money,
love like you've never been hurt and dance like nobody's watching!