JNLP File Extension

What is JNLP file?

Files with the .JNLP extension contain data stored using XML syntax. Such data concerns an application or a Java applet, which source code is located on a remote computer, and it supposed to be opened locally, according to the Java Network Launching Protocol.

JNLP file contains:

• Information about the application – e. g.: title, producer, description,
• Resources of the application – address of website where the JAR package is located,
• Security measures – right enabling to perform certain actions,
• Target element – class and parameters of an application or a web-applet.

Additional information

JNLP file may also contain many different details about various elements of an application, which specification can be found on the Oracle web pages. It can be run in the JRE environment. Content of a file can be displayed using any text editor.

Programs which support JNLP file extension

The list that follows enumerates programs compatible with JNLP files, divided into 3 categories based on operating system on which they are available. Files with JNLP extension, just like any other file formats, can be found on any operating system. The files in question may be transferred to other devices, be it mobile or stationary, yet not all systems may be capable of properly handling such files.

Updated: 08/19/2019

How to open file with JNLP extension?

There can be multiple causes why you have problems with opening JNLP files on given system. Fortunately, most common problems with JNLP files can be solved without in-depth IT knowledge, and most importantly, in a matter of minutes. We have prepared a listing of which will help you resolve your problems with JNLP files.

Step 1. Install Java Web Start software

The most common reason for such problems is the lack of proper applications that supports JNLP files installed on the system. The solution to this problem is very simple. Download Java Web Start and install it on your device. On the top of the page a list that contains all programs grouped based on operating systems supported can be found. One of the most risk-free method of downloading software is using links provided by official distributors. Visit Java Web Start website and download the installer.

Step 2. Check the version of Java Web Start and update if needed

You still cannot access JNLP files although Java Web Start is installed on your system? Make sure that the software is up to date. Software developers may implement support for more modern file formats in updated versions of their products. If you have an older version of Java Web Start installed, it may not support JNLP format. All of the file formats that were handled just fine by the previous versions of given program should be also possible to open using Java Web Start.

Step 3. Assign Java Web Start to JNLP files

After installing Java Web Start (the most recent version) make sure that it is set as the default application to open JNLP files. The process of associating file formats with default application may differ in details depending on platform, but the basic procedure is very similar.

Selecting the first-choice application in Windows

• Clicking the JNLP with right mouse button will bring a menu from which you should select the Open with option
• Click Choose another app and then select More apps option
• The last step is to select Look for another app on this PC option supply the directory path to the folder where Java Web Start is installed. Now all that is left is to confirm your choice by selecting Always use this app to open JNLP files and clicking OK.

Selecting the first-choice application in Mac OS

• By clicking right mouse button on the selected JNLP file open the file menu and choose Information
• Proceed to the Open with section. If its closed, click the title to access available options
• Select Java Web Start and click Change for all...
• A message window should appear informing that This change will be applied to all files with JNLP extension. By clicking Continue you confirm your selection.

Step 4. Check the JNLP for errors

You closely followed the steps listed in points 1-3, but the problem is still present? You should check whether the file is a proper JNLP file. It is probable that the file is corrupted and thus cannot be accessed.

1. Verify that the JNLP in question is not infected with a computer virus

Should it happed that the JNLP is infected with a virus, this may be that cause that prevents you from accessing it. Scan the JNLP file as well as your computer for malware or viruses. If the scanner detected that the JNLP file is unsafe, proceed as instructed by the antivirus program to neutralize the threat.

2. Verify that the JNLP file’s structure is intact

If the JNLP file was sent to you by someone else, ask this person to resend the file to you. During the copy process of the file errors may occurred rendering the file incomplete or corrupted. This could be the source of encountered problems with the file. When downloading the file with JNLP extension from the internet an error may occurred resulting in incomplete file. Try downloading the file again.

3. Check if the user that you are logged as has administrative privileges.

Sometimes in order to access files user need to have administrative privileges. Log in using an administrative account and see If this solves the problem.

4. Make sure that the system has sufficient resources to run Java Web Start

If the system is under havy load, it may not be able to handle the program that you use to open files with JNLP extension. In this case close the other applications.

5. Verify that your operating system and drivers are up to date

Regularly updated system, drivers, and programs keep your computer secure. This may also prevent problems with Java Web Start Format files. Outdated drivers or software may have caused the inability to use a peripheral device needed to handle JNLP files.

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