How to Test Java

Have you tried using an online service based on Java technology, but it returns an error message? Are you told that Java is not installed on your computer or that the plugin cannot be enabled in the browser? Don't despair, I'm here today to explain how to solve the problem.

Thanks to a special tool available directly on the Java site, you can test the functioning of the plugin and find out if it is installed and / or configured correctly in your browser. If the test fails, you can activate Java in your browser or reinstall the plugin following the instructions you find in my tutorial.

But be careful, Java is not compatible with all programs for surfing the Internet. Being often the subject of dangerous security holes and being used by a very small number of online services, Java is no longer supported by many browsers who have chosen to completely cut support for the latter. This means that on certain online browsers there is nothing you can do to get the plugin back to working properly. Having made this necessary premise, let's get down to business and see how to test Java (and eventually reactivate it) in all browsers that still support it. It is not difficult.

How to Test Java in the Browser

As mentioned above, Java support within Internet browsing programs is becoming increasingly rare. The only browsers that currently support the plugin are Firefox, Internet Explorer and Safari. Chrome as of version 45 (released September 2015), no longer supports Java and plugins based on NPAPI technology, while Edge has never supported Java and never will. Having made this necessary premise, let's see how to test Java in online browsing programs that still support it.

Firefox

To test Java in Firefox, connected to the Java website and first click on the button Accept and then on the voice Do I have Java? located below the program download button.

On the page that opens, click on the button Check the Java versionclick here lego brick displayed in the center of the page and choose the option Allow now from the menu that appears at the top left to authorize the one-time Java execution.

At this point a Java warning should appear in the center of the screen. Then click on the button Run to authorize the execution of Java on the page and within a few seconds the message should appear Congratulations! Recommended Java software is installed.

If the message appears instead of the congratulatory message A newer version of Java is available, it means that Java is correctly installed on your computer but has not been updated to the latest version available. To update it, download it "manually" by clicking on the button Download Java now or follow the next chapter of this tutorial.

If the test fails and / or the menu to allow Java to run in Firefox does not appear, try accessing your browser settings and enabling Java from there.

To enable the Java plugin in Firefox, click on the button located at the top right and select the icon Additional components from the menu that appears. In the tab that opens, choose the item Plugin from the left sidebar, locate the items Java (TM) Platform, Java Applet Plug-in e Java Deployment Toolkit and set on Ask before activating the drop-down menus located next to them.

I strongly advise against setting the option Always active, as in this way Java would always start automatically, thus facilitating the execution of potentially malicious scripts.

Internet Explorer

It was used Internet Explorer, you can test Java by connecting to this web page and clicking on the button first Accept and then on the voice Do I have Java? which is located under the Java download button.

On the page that opens, press the button Check the Java version and wait a few seconds. If Java is installed and properly configured in Internet Explorer, you will see the message appear Congratulations! Recommended Java software is installed.

If you see the message A newer version of Java is available, it means that Java is correctly installed on the PC but has not been updated to the latest version available. To update it, click on the button Download Java now or follow the next chapter of the tutorial.

If the test fails, i.e. Java doesn't run in Internet Explorer, try enabling the plugin in Internet Explorer settings.

To activate the Java plugin in the Internet Explorer settings, click on thegear che si trova in alto a destra e seleciona la voce Internet options from the menu that appears. Then go to the tab Safety, click the button Custom level ..., locate the option relating toScripting Java applets and apponi il segno di spunta accanto alla voce Ask for confirmation.

In this way you will have the possibility to run Java within Internet Explorer, but only on request, that is with your explicit consent (a factor that limits the risk of running potentially dangerous scripts in the browser).

Safari

If you have a Mac and use Safari to surf the Internet, you can test the functioning of Java by connecting to this web page and clicking on the button first Accept and then on the voice Do I have Java? located under the Java download button.

On the page that opens, click on the button first Check the Java version, by your complaint Click to use Java which is displayed in the center of the page and finally on that Use once which appears at the top.

At this point, click on the button again Check the Java version, Reply Run at the warning that appears on the screen and within a few seconds you should find out if Java is installed correctly and if you need to download updates.

If you need to update Java, click the button Download Java now and proceed with the "manual" installation of the software or follow the next chapter of the tutorial.

If Java is not detected, try going to the menu Safari> Preferences and enable the plugin from there. To be even more specific, what you need to do is select the tab Safety, click on the button Plugin Settings ... and put the check mark next to the entry for Java. After that you need to set the option Ask in the drop-down menu When I visit other websites and you have to click on the button end.

This way you will have enabled Java in Safari, but only on request, that is, only after giving it an explicit authorization every time a script tries to start in the browser.

Check the Version of Java Installed on Your Computer

If you want test Java meaning you want to find out if the software version installed on your computer is the most recent one, proceed as follows.

Windows

If you use a PC Windowsclick on your button Start (the flag located in the lower left corner of the screen), type the terms control panel in the menu that opens and select the first search result. In the window that opens, then expand the drop-down menu View by (top right) and choose an option from Big icons e Small icons from the latter.

At this point, select the icon Java, go to the card Update of the window that opens and click on the button Update now to check for new software versions. If new versions of Java are available, accept their installation by clicking on the appropriate button.

Poppy

If you use a Poppy, you can check for Java updates by opening System preference (the gear icon found in the Dock bar) and selecting the Java from the window that opens.

So wait a few seconds for the Java control panel to load, go to the tab Update and starts checking for updates. If updates are available, accept their installation on your computer by clicking on the buttons Update now e Install.

What to Do if Java Doesn't Work

Despite having followed the instructions above, are you unable to use Java on your PC? Then try one of the solutions shown below into practice.

Reinstall Java

The first piece of advice I would like to give you, however trivial, is to try uninstalling Java and reinstalling it.

To uninstall Java, open the Windows Control Panel, click on the icon Uninstall a program, locate Java in the list of applications on your computer and click on the button Uninstall which is located at the top left.

If you are using a Mac, you can uninstall Java by opening the terminal (found in the folder Other Launchpad) and giving the following commands.

  • sudo rm -fr /Library/Internet Plug-Ins/JavaAppletPlugin.plugin
  • sudo rm -fr /Library/PreferencesPanes/JavaControlPanel.prefPane
  • sudo rm -fr ~/Library/Application Support/Java

Then, to reinstall Java, all you have to do is connect to the software website and click on the button first Java Free Download and then Accept and start free download.

Once the download is complete, open the Java installation package (which on Windows is in exe while on Mac it is in dmg/pkg) and always click on forward to finish the setup. Remember to remove the check mark from the item related to Yahoo! not to change the home page and search engine in your browsers.

Reset Java Bindings

If Java works in the browser but not on the PC, where you may not be able to open applications in JAR, try to restore the software association with the files in question.

To reset Java associations, you need to enter the Windows registry by giving the command regedit in the Start menu. After that you have to locate the following keys and you have to delete them (please, delete only the "jar" keys and not the rest of the path).

  • [HKEY_CLASSES_ROOT.jar]
  • [HKEY_CLASSES_ROOTSystemFileAssociations.jar]
  • [HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionExplorerFileExts.jar]

When completed, start the Command Prompt as administrator and give the following commands.

  • assoc .jar = JARFile
  • ftype JARFile="C:Program Files (x86)Javajre1.8.0_51binjavaw.exe" -jar "%1"

Instead of "C: Program Files (x86) Java jre1.8.0_51 bin javaw.exe you have to enter the path of the Java Runtime Environment on your PC. If you don't know what it is, open theFile Explorer di Windows, or in C: Program Files (x86) and find out the path where the file is javaw.exe inside the Java folder.

If any of the steps aren't clear to you and / or you want more instructions on how to reset Java associations on Windows, check out my guide on how to open JAR files. I recommend, before starting the registry, make a backup of it as I explained to you in my guide on how to open the registry.

If you're using a Mac, a reinstall of the software should be enough to fix the problem with JAR files or other Java-related files.