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Many browser widgets in many threads [message #507952]

Fri, 15 January 2010 09:54

nysalsa

Messages: 2
Registered: January 2010

Junior Member

Hi all, I'm facing a problem during the development of a test tool that implements the simulation of many different page requests from many browser instances.
I'm on a WinXP Sp2 box w/ JDK 1.6.0_16, Galileo Eclipse, Eclipse SDK 3.5.1 and SWT 3.555.
With the two following classes:

Test.java

import java.util.ArrayList;

import org.eclipse.swt.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.browser.*;
import org.eclipse.swt.layout.*;

public class Test {

/**
* @param args
* @throws InterruptedException
*/
public static void main(String[] args) throws InterruptedException {
Display display = new Display();
ArrayList<BrowserThread> brThreads = new ArrayList<BrowserThread>();
String[] sites = {"http://www.ansa.it", "http://www.apple.com"};

try {

for(String value : sites) {
BrowserThread brThr = new BrowserThread(display, value);
brThreads.add(brThr);
brThr.start();
}

for (BrowserThread brThr: brThreads) {
if (brThr.isAlive()) {
brThr.join();
}
}

} catch (SWTError e) {
System.out.println("Could not instantiate Browser: " + e.getMessage());
//shell.dispose();
return;
}
//display.dispose();
}
}

and BrowserThread.java

import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTError;
import org.eclipse.swt.browser.Browser;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

/**
* @author 11612764
*
*/
public class BrowserThread extends Thread {

private Display display;
private Shell shell;
private String url;

BrowserThread(Display display, String url) {
this.display = display;
this.url = url;
this.shell = new Shell(display);
shell.setLayout(new FillLayout());
shell.setText(url);
}

public void run() {
Browser browser;
try {
browser = new Browser(this.shell, SWT.NONE);

shell.open();
browser.setUrl(url);

while (!shell.isDisposed()) {
if (!display.readAndDispatch()) Thread.sleep(5000);
}
shell.dispose();
} catch (SWTError e) {
System.out.println("Could not instantiate Browser: " + e.getMessage());
shell.dispose();
return;
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}

I obtained the following error:

Exception in thread "Thread-0" org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.widgets.Widget.error(Unknown Source)
at org.eclipse.swt.widgets.Widget.checkWidget(Unknown Source)
at org.eclipse.swt.widgets.Widget.checkParent(Unknown Source)
at org.eclipse.swt.widgets.Widget.<init>(Unknown Source)
at org.eclipse.swt.widgets.Control.<init>(Unknown Source)
at org.eclipse.swt.widgets.Scrollable.<init>(Unknown Source)
at org.eclipse.swt.widgets.Composite.<init>(Unknown Source)
at org.eclipse.swt.browser.Browser.<init>(Unknown Source)
at BrowserThread.run(BrowserThread.java:30)
Exception in thread "Thread-1" org.eclipse.swt.SWTException: Invalid thread access
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.SWT.error(Unknown Source)
at org.eclipse.swt.widgets.Widget.error(Unknown Source)
at org.eclipse.swt.widgets.Widget.checkWidget(Unknown Source)
at org.eclipse.swt.widgets.Widget.checkParent(Unknown Source)
at org.eclipse.swt.widgets.Widget.<init>(Unknown Source)
at org.eclipse.swt.widgets.Control.<init>(Unknown Source)
at org.eclipse.swt.widgets.Scrollable.<init>(Unknown Source)
at org.eclipse.swt.widgets.Composite.<init>(Unknown Source)
at org.eclipse.swt.browser.Browser.<init>(Unknown Source)
at BrowserThread.run(BrowserThread.java:30)

Any advice?
Thank you

Rob

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Re: Many browser widgets in many threads [message #508018 is a reply to message #507952]

Fri, 15 January 2010 15:08

Grant Gayed

Messages: 2150
Registered: July 2009

Senior Member

See http://www.eclipse.org/swt/faq.php#uithread , all swt interactions must
be on the main UI thread.

Grant

"nysalsa" <nysalsa@hotmail.it> wrote in message
news:hipe0n$g8o$1@build.eclipse.org...
> Hi all, I'm facing a problem during the development of a test tool that
implements the simulation of many different page requests from many browser
instances.
> I'm on a WinXP Sp2 box w/ JDK 1.6.0_16, Galileo Eclipse, Eclipse SDK 3.5.1
and SWT 3.555.
> With the two following classes:
>
> Test.java
>
> import java.util.ArrayList;
>
> import org.eclipse.swt.*;
> import org.eclipse.swt.widgets.*;
> import org.eclipse.swt.browser.*;
> import org.eclipse.swt.layout.*;
>
> public class Test {
>
> /**
> * @param args
> * @throws InterruptedException
> */
> public static void main(String[] args) throws InterruptedException {
> Display display = new Display();
> ArrayList<BrowserThread> brThreads = new ArrayList<BrowserThread>();
> String[] sites = {"http://www.ansa.it", "http://www.apple.com"};
>
> try {
>
> for(String value : sites) {
> BrowserThread brThr = new BrowserThread(display, value);
> brThreads.add(brThr);
> brThr.start();
> }
>
> for (BrowserThread brThr: brThreads) {
> if (brThr.isAlive()) {
> brThr.join();
> }
> }
>
> } catch (SWTError e) {
> System.out.println("Could not instantiate Browser: " + e.getMessage());
> //shell.dispose();
> return;
> }
> //display.dispose();
> }
> }
>
> and BrowserThread.java
>
> import org.eclipse.swt.SWT;
> import org.eclipse.swt.SWTError;
> import org.eclipse.swt.browser.Browser;
> import org.eclipse.swt.layout.FillLayout;
> import org.eclipse.swt.widgets.Display;
> import org.eclipse.swt.widgets.Shell;
>
> /**
> * @author 11612764
> *
> */
> public class BrowserThread extends Thread {
>
> private Display display;
> private Shell shell;
> private String url;
>
>
> BrowserThread(Display display, String url) {
> this.display = display;
> this.url = url;
> this.shell = new Shell(display);
> shell.setLayout(new FillLayout());
> shell.setText(url);
> }
>
> public void run() {
> Browser browser;
> try {
> browser = new Browser(this.shell, SWT.NONE);
>
> shell.open();
> browser.setUrl(url);
>
> while (!shell.isDisposed()) {
> if (!display.readAndDispatch()) Thread.sleep(5000);
> }
> shell.dispose();
> } catch (SWTError e) {
> System.out.println("Could not instantiate Browser: " + e.getMessage());
> shell.dispose();
> return;
> } catch (InterruptedException e) {
> // TODO Auto-generated catch block
> e.printStackTrace();
> }
>
> }
>
> }
>
> I obtained the following error:
>
> Exception in thread "Thread-0" org.eclipse.swt.SWTException: Invalid
thread access
> at org.eclipse.swt.SWT.error(Unknown Source)
> at org.eclipse.swt.SWT.error(Unknown Source)
> at org.eclipse.swt.SWT.error(Unknown Source)
> at org.eclipse.swt.widgets.Widget.error(Unknown Source)
> at org.eclipse.swt.widgets.Widget.checkWidget(Unknown Source)
> at org.eclipse.swt.widgets.Widget.checkParent(Unknown Source)
> at org.eclipse.swt.widgets.Widget.<init>(Unknown Source)
> at org.eclipse.swt.widgets.Control.<init>(Unknown Source)
> at org.eclipse.swt.widgets.Scrollable.<init>(Unknown Source)
> at org.eclipse.swt.widgets.Composite.<init>(Unknown Source)
> at org.eclipse.swt.browser.Browser.<init>(Unknown Source)
> at BrowserThread.run(BrowserThread.java:30)
> Exception in thread "Thread-1" org.eclipse.swt.SWTException: Invalid
thread access
> at org.eclipse.swt.SWT.error(Unknown Source)
> at org.eclipse.swt.SWT.error(Unknown Source)
> at org.eclipse.swt.SWT.error(Unknown Source)
> at org.eclipse.swt.widgets.Widget.error(Unknown Source)
> at org.eclipse.swt.widgets.Widget.checkWidget(Unknown Source)
> at org.eclipse.swt.widgets.Widget.checkParent(Unknown Source)
> at org.eclipse.swt.widgets.Widget.<init>(Unknown Source)
> at org.eclipse.swt.widgets.Control.<init>(Unknown Source)
> at org.eclipse.swt.widgets.Scrollable.<init>(Unknown Source)
> at org.eclipse.swt.widgets.Composite.<init>(Unknown Source)
> at org.eclipse.swt.browser.Browser.<init>(Unknown Source)
> at BrowserThread.run(BrowserThread.java:30)
>
> Any advice?
> Thank you
>
> Rob
>
>
>

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Re: Many browser widgets in many threads [message #508804 is a reply to message #507952]

Wed, 20 January 2010 11:48

nysalsa

Messages: 2
Registered: January 2010

Junior Member

Thank you Grant, I understood in another way that part of the documentation (my fault... sorry).
This drives a question: having to simulate many user page-requests with pre-defined gap between then (i.e. 4 secs between the first and the second one) how can I do that ?
I read that the page rendering is asynchronous but it seems that that second request waits for the complete page rendering of the first one.
What I'm missing ?
Thank you in advance

Rob

Report message to a moderator

Re: Many browser widgets in many threads [message #508874 is a reply to message #508804]

Wed, 20 January 2010 15:46

Grant Gayed

Messages: 2150
Registered: July 2009

Senior Member

You can use Display.timerExec() to execute something after a specified
number of milliseconds has passed, for an example of this see
http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.swt.sni ppets/src/org/eclipse/swt/snippets/Snippet16.java?view=co .

The native browsers generally should not wait for a page rendering to
complete if a setUrl() or setText() is issued in the meantime, though it's
ultimately up to the native browser implementation to handle this. If you
want to be notified of when a page load completes then you can add a
ProgressListener to the Browser and its completed() method will be invoked.

Grant

"nysalsa" <nysalsa@hotmail.it> wrote in message
news:hj6qjd$1g2$1@build.eclipse.org...
> Thank you Grant, I understood in another way that part of the
documentation (my fault... sorry).
> This drives a question: having to simulate many user page-requests with
pre-defined gap between then (i.e. 4 secs between the first and the second
one) how can I do that ?
> I read that the page rendering is asynchronous but it seems that that
second request waits for the complete page rendering of the first one.
> What I'm missing ?
> Thank you in advance
>
> Rob

Report message to a moderator

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