I have a web application (struts 1.3, Weblogic 10.3.0, Toplink, Oracle) that has a Java applet which isn’t working in the browser (IE7/8) when the Next-Generation Plug-in setting is enabled in the Java control panel but works fine when it’s disabled. The trouble is that this setting is set to disappear in an upcoming Java release meaning that my users would have to keep using Java 1.6_xx on their workstations as they are currently. I have little influence over which version they use because they are all governed by their local IT departments across the country. So, either I have to find a simple fix to allow the Next-Generation setting to work, or we have to look at replacing/rewriting the applet with something else (but would be a last resort due to funding constraints), most likely something AJAX-friendly so as to avoid the need for a plugin. This application is quite old, written around 2001 before AJAX was really around.
The main window has a left, right, and top frame (JSP’s), as well as a center frame which is where the applet is. The applet has a main content area in the middle and a lower panel at the bottom which has some buttons. The buttons tell the content area (which is basically a treegrid) what to do (Save, Copy, change status, etc ). When I press one of the buttons the entire window (surrounding frames plus the applet itself) repeat inside the area where the applet is. It’s like a kaleidoscope or like a repeating fractal pattern kind of thing, or like when you take a picture of yourself in the mirror and you see the room repeated over and over in the mirror. In this case it repeats for each button press and the repeated set gets smaller each time. Weird!!
So, based on my research, the Java Next-Generation plugin works differently by allowing more than one process or thread whereas the classic plugin only uses a single thread. So my suspicion is that a new process is being spawned for each button press. I tried using the “separate_jvm” applet parameter but it made no difference whether it was set to true or false. I don’t see any other applet parameters which seem to be relevant.
Another idea I had is that maybe it’s something to do with the JSP frameset, maybe something like “target=_top” needs to be added somewhere…but I’m not sure how this relates to applet threads if at all.
Anyone have any suggestions, ideas or experiences that might help?
you can use velocity to handle these type of problem and it will also help you for future enhancement also.
The problem is not related to version of IE but rather to version of Java. Below excerpt from letter of certificate provider (they took it from some forum, so direct link to source cannot be provided):
For JDK version higher than 1.6.0 and below 1.6_15, you can just
clear all kinds of cache in web browser, java console and java control
panel. Then it should works fine!
For JDK version between 1.6_15 and 1.6_30, you should disable the "next-generation java" option in java control panel.
For JDK version higher than 1.6_30, you should turn on "next-generation java" option in java control panel.
Related
In this page the CheerpJ conversion of the applet in this page (with identical byte-code) does not seem to recognize mouse dragging past the applet frame boundary. It would be nice if that were possible.
Is this just a problem with my client-side setup (Linux Debian 9.2), or do others see the same behvior?
What is very strange, is that the original behavior is converted correctly on the not-supported-by-CheerpJ iphone browsers (I have checked safari and firefox there). Could investigation of this fact help CheerpJ developers understand how to make the MouseMotionListener interface recognize mouse dragging anywhere on the screen, not just within the applet frame?
Maybe this is impossible, but I thought it was worth asking.
Edit: Changed title to be less negative about CheerpJ (which overall I find almost too cool to be true!) and more reflective of actual the question.
The mouseDragged method is correctly implemented to the best of our understanding. The Java event is derived from the mousemove JavaScript event which is not delivered when the mouse is outside of the applet surface. With the legacy plugin applets are displayed on native windows which have different behavior.
It could be possible that using different JavaScript events, like mousedrag would make CheerpJ behavior more similar to native, but reworking this without causing regressions would require significant work and it is not currently a priority for us. Especially considering that our customers normally have full screen Swing applets which cannot exhibit the problem
On mobile devices the touchmove event is used, which is probably what causes the difference you see.
If you want to report a bug you can do it here: https://github.com/leaningtech/cheerpj-meta/issues
I have a Java/JavaFX application deployed as a native install for Windows and Mac. The bundled runtime is currently 8.121. You can find the installers and the Java code here: George download
I have been using this application in the classroom weekly (with 20 children) for the last 15 months, and right from the start I have seen the following problem:
From time to time, buttons disappear. That is to say, they are simply rendered as a white rectangle, making them effectively almost invisible. Both the background and label/text disappear.
This mainly happens on mouse-over, but then does not correct itself.
The buttons are still there, and clickable.
It only happens sporadically, but it seems to recur on certain machines more than others. Windows 10 now, but used to the same happened on tiny Windows 7 machines previously.
I am not able to reproduce it myself and have never seen it on a Mac, I think.
It now also happens sometimes with other widgets/controls, and even before any user interaction.
Is there some known issue around this?
Has anyone else described something similar?
Might it have something to do with certain minor operating system adjustments?
Any thoughts or ideas would be much appreciated.
Update (2018-11-06)
Just started testing my application in Java 8 in VirtualBox with Windows 10, and I now get the rendering error myself. Hurra!
Looking into the -Dprism.xxx options, I found this article:
http://werner.yellowcouch.org/log/javafx-8-command-line-options/
Testing with -Dprism.threadcheck=true, I get a lot of
"ERROR: PrismPen / FX threads co-running: DIRTY: false" with stack traces.
Setting -Dprism.dirtopts=falsedoes not solve it for me, though.
But running with -Dprism.order=sw does. But this is not a good solution for an application that may do some demanding rendering (Turtle Geometry).
Will keep digging.
I've been having the same issue, I tried updating to Java 10 but the issue remained. I then edited the properties on java.exe and on the 'Compatibility' tab I set 'Override high DPI scaling behavior' to 'System (enhanced)' and the problem seems to have gone away (or at least it hasn't happened again yet).
I observed the same thing: Visually disappearing (but still functional) buttons and other controls (except labels) especially in areas outside the original size of the window after I have resized it manually)
In my case -Dprism.dirtopts=false reduced the problem but also didn't solve it (and was not really a satisfying solution anyway).
Additionally I observed that some TextField controls also showed rendering glitches (looked like the same text was rendered twice with a little offset). That finally put me on the right track:
It turned out to be just a missing Platform.runLater(...) around some calls to TextField.setText(...) (from another thread) for exactly these TextField controls, which was causing this (even for e.g. a Button which is at a totally different place - also in the widget hierarchy).
I know, this is probably not the answer in all cases, but hopefully it helps at least some others facing the same problem (took me a full day to find out).
I have made a Screen Recorder using Java Swing and Xuggler 5.4. I have developed it in Windows 8 64 bit. It's working excellent for Windows. But at client side on Linux's environment , nothing is working. I have searched thoroughly but not getting any solutions. I have checked this thread , but it didn't work for me.
Then I tried to create simple Transparent window in Linux but it's also not working. I was not able to click through the Resizeable Panel. I have used the same JRE version (1.7) for both. Have I miss understood Java's Cross Platform Support as far as Swing is concerned?
Please Give Me Some Advice...
I have always found logging to be the best debugging tool at your disposal! Many a times, java debuggers take you into APIs where you need not go every time. Logging values of your variables, and generic 'I have reached till this point' statements make life a lot easier.
So, I suppose you have ample logging done in your code. That could give you clues on what's happening on your client's system.
Are the right environment variables set? Are they pointing to the correct Java versions you need.
If there are some specific Screen capturing requirements(plugins / modules / API) your code has, are they available on the Linux m/c?
Like #MadProgrammer said, in the end, Java has to talk with the native graphics APIs to render your screen.
I would try to debug it in this way -
Check whether my main screen loads or no(by disabling the screen capture functions for a while).
if not, dig deeper.
Check whether all necessary components for capturing screen(audio and video) are available.
Check whether the code is being run with appropriate permissions to control the h/w devices you may need.
Later versions of MacOS (> 10.5?) support a spiffy property, AppleDisplayScaleFactor - the scale factor for an application window, which can be set either globally, or for a specific application (identified by the CFBundleIdentifier in the app's info.plist - as I understand it).
BUT... my Java Swing application is a mess when I use this value globally - clicks don't match up with buttons, bad screen painting and so forth - and the same thing happens running JavaSoundDemo. And when I try to use it in a app-specific manner it is never used at all (I tried a variety of "identifiers" for the app - CFBundleIdentifier for the app, for the JVM, and the Main class, which is used as the title for the JVM window).
I'm just hoping that some brave and clever soul has figured out how to make this actually work - the Apple docs on "Resolution-Independent Display" claim that Java simply does everything for you. Perhaps this really should be a bug report to Apple - thanks in advance.
I've found that AppleDisplayScaleFactor doesn't work across all applications (such as Flash within a browser). So it doesn't surprise me that it doesn't work properly with Java Swing.
We have a Java Applet built using AWT. This applet lets you select pictures from your hard drive and upload them to a server. The applet includes a scrollable list of pictures, which works fine in Windows, Linux and Mac OS X 10.5. We launch this applet via Java Web Start or within a web page.
Our applet does not behave properly in Mac OS X 10.4, regardless of the version of Java (1.4 or 1.5). You can find a screenshot of the incorrect behaviour, when scrolling, here:
http://www.lavablast.com/tmp/ui_error.png
Simply put, sometimes when scrolling the pictures end up overlapping the header or footer of the application. This behaviour does not occur on other platforms. On Mac OS X 10.4, it shows the pictures in the incorrect location when scrolling, which would not be so bad if it refreshed the screen after painting the image at that location. However, it does not appear that the application knows it painted it incorrectly and thus does not refresh.
If the window is minimized, resized or even moved, the application is refreshed and the incorrectly positioned elements vanish and the application resumes normally. I spent quite some time trying to force a refresh of the background image unsuccessfully. (the repaint the image directly, repaint all children of a few panels, etc. ) Thus, I am looking for any tips that would help me resolve this problem under Mac OS X 10.4 or, in the worst case, simply simulate a full applet refresh.
Until recently, everything was compatible with Java 1.1 but this has changed in a few locations which now require 1.4. I don't feel these changes created the issue, I am just providing this as extra information. If you are interested in implementation details of the scroll panel, I will investigate, but I am assuming this is a common platform bug for which workarounds must be known.
To replicate the problem, open the following Java Web Start application:
http://www.lavablast.com/tmp/opal-webstart.php.jnlp
Select a folder containing lots of images and play with the scrollbar. At some point (fairly quickly), you should get the refresh problem.
Edit: I followed the first suggestion here and replaced all my controls that feature background images with a Swing equivalent and the issue is still there. (Plus, there are numerous other fixes I would need to do to do a complete change). Any other ideas? A simple one line of code that forces a full refresh would be great :)
Edit2: The main thread creates the panels and launches X threads. Using an observer/notifier pattern, the threads complete and notify the main control, which adds a panel to the page. This is done via an EventQueue.invokeLater which, unless I am mistaken, should run on the right thread. The issue is at its most severe when scrolling even if no extra threads are running (as during the loading).
It does look like mixing lightweight (usually Swing) and heavyweight (AWT) components together. Moving to Swing you need to replace every last AWT component Swing equivalents (hint: avoid import java.awt.*).
Threading is often a potential problem for odd bugs. Swing components must always be used on the EDT (use java.awt.EventQueue.invokeLater). AWT is thread-safe is theory, but not in practice - also restrict usage to the EDT.
As you already require Java 1.4 you should consider some small changes to take into use SWING GUI instead, it solved our Applet refresh issues with AWT. (Mac, Linux etc)
If you have e.g. Panel, you need to replace it with JPanel etc.
You need this:
import javax.swing.*;