vade

Hello, the following code works in the command line properly:

    public static void main(String[] args)

            System.out.println("Attempting to download");

                URL test = new URL("

                InputStreamReader UrlInputStream= new InputStreamReader(test.openStream());

                BufferedReader in = new BufferedReader(UrlInputStream);

                String inputLine = "blah";

                while((inputLine = in.readLine()) != null)

                     System.out.println(inputLine);

                in.close();

            catch (MalformedURLException e)

                System.out.println("It appears as though your URL is malformed");

            catch(IOException e)

                e.printStackTrace();

                System.out.println("Network error - cannot connect to URL");

However, when making an mxj object with similar code, I get this error:

? error: java.io.IOException: Stream closed

? error:     at java.io.BufferedReader.ensureOpen(BufferedReader.java:97)

? error:     at java.io.BufferedReader.readLine(BufferedReader.java:293)

? error:     at java.io.BufferedReader.readLine(BufferedReader.java:362)

? error:     at imagedownloader.bang(imagedownloader.java:42)

* shows the basic transaction between the Max patcher and an

* mxj object that wants to process a matrix of data

public class imagedownloader extends MaxObject

    public void setUrl(String newUrl)

        UrlString = newUrl;    

            post("Attempting to download " + UrlString);

                URL test = new URL(UrlString);

                    // post(inputLine);

                post("It appears as though your URL is malformed");

                 e.printStackTrace();

                post("Network error - cannot connect to URL");

                post("asfd");

class test
{
	public static void main(String[] args)
	{
		bang();
	}

	public static void bang()
	{
			System.out.println("Attempting to download");

			try
			{
				URL test = new URL("http://www.yahoo.com");

				InputStreamReader UrlInputStream= new InputStreamReader(test.openStream());

				BufferedReader in = new BufferedReader(UrlInputStream);
				String inputLine = "blah";
				while((inputLine = in.readLine()) != null)
					 System.out.println(inputLine);
				in.close();

			}
			catch (MalformedURLException e)
			{

				System.out.println("It appears as though your URL is malformed");
			}
			catch(IOException e)
			{
				e.printStackTrace();
				System.out.println("Network error - cannot connect to URL");
			}

Attempting to download http://www.yahoo.com
? error: java.io.IOException: Stream closed
? error: 	at java.io.BufferedReader.ensureOpen(BufferedReader.java:97)
? error: 	at java.io.BufferedReader.readLine(BufferedReader.java:293)
? error: 	at java.io.BufferedReader.readLine(BufferedReader.java:362)
? error: 	at imagedownloader.bang(imagedownloader.java:42)
Network error - cannot connect to URL
asfd

[code]
import java.net.*;
import java.io.*;
import com.cycling74.max.*;

/**
 * @author bbn
 *
 * shows the basic transaction between the Max patcher and an
 * mxj object that wants to process a matrix of data
 */
public class imagedownloader extends MaxObject
{

	String UrlString = "http://www.yahoo.com";

	public void setUrl(String newUrl)
	{
		UrlString = newUrl;	
	}

	public void getUrl()
	{
		post(UrlString);
	}

	public void bang()
	{
			post("Attempting to download " + UrlString);

			try
			{
				URL test = new URL(UrlString);

				BufferedReader in = new BufferedReader(UrlInputStream);
				String inputLine = "blah";
				while((inputLine = in.readLine()) != null)
					// post(inputLine);
				in.close();

				post("It appears as though your URL is malformed");
			}
			catch(IOException e)
			{
				 e.printStackTrace();
				post("Network error - cannot connect to URL");
				post("asfd");
			}
			;
	}

mxj-issue-throwing-ioexception-where-java-from-cli-is-not

everything looks kosher at first glance, although you will probably

eventually want to start a separate thread to retrieve the data. you

might try that right away to see if retrieiving in a separate thread

eliminates the IOException. (don't know why it would, but that's what

Does the error message show up right away, or is there a delay?

everything looks kosher at first glance, although you will probably
eventually want to start a separate thread to retrieve the data.  you
might try that right away to see if retrieiving in a separate thread
eliminates the IOException.  (don't know why it would, but that's what
I would try first.)

Ben - thanks for the quick reply. There seems to be no delay. I must admit, Im currently at a network im not familiar with. I dont believe I am behind a proxy, but I will try it from home, where I know whats going on network wise - and I am unfiltered. However I see no indication OS wise / or in any other app that I am filtered/proxied.

RE: threads - exactly my goal. However I am very new to java, so thats a bit above my current level of understanding.

Any chance someone could point me in the right direction? The goal of this exercise is to make a threaded image downloader to alleviate the horrible stutters I get with jit.uldl.

Ben - thanks for the quick reply. There seems to be no delay. I must admit, Im currently at a network im not familiar with. I dont believe I am behind a proxy, but I will try it from home, where  I know whats going on network wise - and I am unfiltered. However I see no indication OS wise / or in any other app that I am filtered/proxied. 

To learn about Java and threads I recommend studying one of the

hundreds of Java dev books or one of the thousands of Java dev sites.

For a quick start, here's a simple pattern that will create and run a

}                        

Sorry about the lousy formatting of the email client code!

> Ben - thanks for the quick reply. There seems to be no delay. I must admit, Im currently at a network im not familiar with. I dont believe I am behind a proxy, but I will try it from home, where I know whats going on network wise - and I am unfiltered. However I see no indication OS wise / or in any other app that I am filtered/proxied.

> RE: threads - exactly my goal. However I am very new to java, so thats a bit above my current level of understanding.

> Any chance someone could point me in the right direction? The goal of this exercise is to make a threaded image downloader to alleviate the horrible stutters I get with jit.uldl.

To learn about Java and threads I recommend studying one of the
hundreds of Java dev books or one of the thousands of Java dev sites.
For a quick start, here's a simple pattern that will create and run a
new thread.

Thread t = new Thread( new Runnable() {
public void run()
{		
  //put your code here	
}						
} );

Sorry about the lousy formatting of the email client code!
Ben

On 6/19/06, vade  wrote:
>
> Ben - thanks for the quick reply. There seems to be no delay. I must admit, Im currently at a network im not familiar with. I dont believe I am behind a proxy, but I will try it from home, where  I know whats going on network wise - and I am unfiltered. However I see no indication OS wise / or in any other app that I am filtered/proxied.
>
> RE: threads - exactly my goal. However I am very new to java, so thats a bit above my current level of understanding.
>
> Any chance someone could point me in the right direction? The goal of this exercise is to make a threaded image downloader to alleviate the horrible stutters I get with jit.uldl.
>
> Thanks for any insight.
>


wow. I suspected it would be much harder than that. Ill give it a go now. Thanks again Ben.

On 19 Jun 2006, at 23:12, Ben Nevile wrote:

> For a quick start, here's a simple pattern that will create and run a

To add to Ben's comments: an important habit to get into is to 

inherit from notifyDeleted() and make sure you clean up your MXJ 

object when its instance is deleted from the patcher. Since a single 

JVM runs to support all your MXJ objects, you don't want to leave any 

threads in the background if their owning MXJ instance goes away.

(It's entirely possible that this is benign, but my understanding of 

Max's threading model and the way it interacts with the JNI calls 

into Java suggests that you should tidy things up carefully.)

nick rothwell -- composition, systems, performance -- 

> For a quick start, here's a simple pattern that will create and run a
> new thread.

To add to Ben's comments: an important habit to get into is to  
inherit from notifyDeleted() and make sure you clean up your MXJ  
object when its instance is deleted from the patcher. Since a single  
JVM runs to support all your MXJ objects, you don't want to leave any  
threads in the background if their owning MXJ instance goes away.

(It's entirely possible that this is benign, but my understanding of  
Max's threading model and the way it interacts with the JNI calls  
into Java suggests that you should tidy things up carefully.)

   nick rothwell -- composition, systems, performance -- http:// 
www.cassiel.com


Thanks Nick. I'll be doing some more in depth reading of the Java docs tonight so hopefully ill get somewhere soon. Thanks again.

if you maintained a reference to a potentially running thread you 

could do a Thread.join() on it in your notifyDeleted() method.

it might result in a spinning ball depending on the situation but at 

least you will be assured that the spawned thread is done executing

On Jun 19, 2006, at 15:28 PM, Nick Rothwell wrote:

> On 19 Jun 2006, at 23:12, Ben Nevile wrote:

>> For a quick start, here's a simple pattern that will create and run a

> To add to Ben's comments: an important habit to get into is to 

> inherit from notifyDeleted() and make sure you clean up your MXJ 

> object when its instance is deleted from the patcher. Since a 

> single JVM runs to support all your MXJ objects, you don't want to 

> leave any threads in the background if their owning MXJ instance 

> (It's entirely possible that this is benign, but my understanding 

> of Max's threading model and the way it interacts with the JNI 

> calls into Java suggests that you should tidy things up carefully.)

> nick rothwell -- composition, systems, performance -- 

good point nick.
if you maintained a reference to a potentially running thread you  
could do a Thread.join() on it in your notifyDeleted() method.
it might result in a spinning ball depending on the situation but at  
least you will be assured that the spawned thread is done executing
before you get rid of the mxj instance.
topher

>
> On 19 Jun 2006, at 23:12, Ben Nevile wrote:
>
>> For a quick start, here's a simple pattern that will create and run a
>> new thread.
>
> To add to Ben's comments: an important habit to get into is to  
> inherit from notifyDeleted() and make sure you clean up your MXJ  
> object when its instance is deleted from the patcher. Since a  
> single JVM runs to support all your MXJ objects, you don't want to  
> leave any threads in the background if their owning MXJ instance  
> goes away.
>
> (It's entirely possible that this is benign, but my understanding  
> of Max's threading model and the way it interacts with the JNI  
> calls into Java suggests that you should tidy things up carefully.)
>
> 	-- N.
>
>
>   nick rothwell -- composition, systems, performance -- http:// 
> www.cassiel.com
>
>
>


Hi. It seems the issue was that I was using post() in my try{}.

This code will print out the contents of the URL via System.out.println. I am assuming this has something to due with scheduling, but I have no idea. I tried it on a random hunch, as I wasnt getting anywhere with the threading. Ill have to approach that later and thread it once I get most of my code working as id like.

Thanks again. Ill be back no doubt with other questions.

        post("Attempting to download " + UrlString);

            URL test = new URL(UrlString);

            URLConnection testConnection =    test.openConnection();

            BufferedReader in = new BufferedReader(

            String inputLine;

            while((inputLine = in.readLine()) != null)

            //    post(inputLine);

                System.out.println(inputLine);

        catch (MalformedURLException e)

            post("It appears as though your URL is malformed");

            e.printStackTrace();

            post("Network error - cannot connect to URL");

[code]
public class imagedownloader extends MaxObject
{

	public void bang()
	{
		post("Attempting to download " + UrlString);

		try
		{
			URL test = new URL(UrlString);

			URLConnection testConnection =	test.openConnection();

			BufferedReader in = new BufferedReader(
                                new InputStreamReader(
                                testConnection.getInputStream()));

			while((inputLine = in.readLine()) != null)
			{
			//	post(inputLine);
				System.out.println(inputLine);
			}	
			in.close();

		}
		catch (MalformedURLException e)
		{
			post("It appears as though your URL is malformed");
		}
		catch(IOException e)
		{
			e.printStackTrace();
			post("Network error - cannot connect to URL");
			post("asfd");
		}
	}
}
[/code]


> Hi. It seems the issue was that I was using post() in my try{}.

try {} just sets up an exception block, so I don't see why it should 

have any effect on posting to the Max world (unlike, say, semaphore 

Are you sending in a bang from a metro (in overdrive) or manually?

try {} just sets up an exception block, so I don't see why it should  
have any effect on posting to the Max world (unlike, say, semaphore  
locks which could well cause problems).

Hi Nick - Im simply banging once, manually, with [button] and overdrive is off.

Could this be a java issue? Here is my version, under OS X 10.4.6.

Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-112)

Java HotSpot(TM) Client VM (build 1.5.0_06-64, mixed mode, sharing)

vade$ java -version
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-112)
Java HotSpot(TM) Client VM (build 1.5.0_06-64, mixed mode, sharing)


If you have Jitter and the goal of your patch is actually to download

an image, take a look in the jitter java examples at

jitwebimage-example. Also shows a nice simple example of threading.

If your goal is to grab pages of HTML, you might find Jakarta-Commons

httpClient to be of use. The sample code on its tutorial web pages

shows how very simple it can be to use, and it will hanlde error

checking and transactions with less hard work on your part.

http://jakarta.apache.org/commons/index.html

http://jakarta.apache.org/commons/httpclient/

> Hi Nick - Im simply banging once, manually, with [button] and overdrive is off.

> Could this be a java issue? Here is my version, under OS X 10.4.6.

> Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-112)

> Java HotSpot(TM) Client VM (build 1.5.0_06-64, mixed mode, sharing)

----- |(*,+,#,=)(#,=,*,+)(=,#,+,*)(+,*,=,#)| -----

If you have Jitter and the goal of your patch is actually to download
an image, take a look in the jitter java examples at
jitwebimage-example. Also shows a nice simple example of threading.

If your goal is to grab pages of HTML, you might find Jakarta-Commons
httpClient to be of use. The sample code on its tutorial web pages
shows how very simple it can be to use, and it will hanlde error
checking and transactions with less hard work on your part.

http://jakarta.apache.org/commons/index.html
http://jakarta.apache.org/commons/httpclient/

On 6/20/06, vade  wrote:
>
> Hi Nick - Im simply banging once, manually, with [button] and overdrive is off.
>
> Could this be a java issue? Here is my version, under OS X 10.4.6.
>
> vade$ java -version
> java version "1.5.0_06"
> Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-112)
> Java HotSpot(TM) Client VM (build 1.5.0_06-64, mixed mode, sharing)
>
>

-- 
-----   |(*,+,#,=)(#,=,*,+)(=,#,+,*)(+,*,=,#)|   -----


Ignotus: Thanks - I somehow missed the jitterwebimage.java file. I will look through it with a fine toothed comb. Thanks for saving me some work!

mxj issue throwing IOexception where Java from CLI is not