This weekend, someone asked me for help with a specific file. He has an Audi and wanted to upgrade his GPS maps. But all he has was an 8 KB downloader file with a JNLP extension. When opening the file, he gets an error that says that the extension is not recognized.
First, I’ll give you Oracles explanation of JNLP:
Java Network Launch Protocol (JNLP) enables an application to be launched on a client desktop by using resources that are hosted on a remote web server.
Ok, we know 2 things:
- Java is needed, that explains the unrecognized problem
- It will download hosted files, that’s why the JNLP is only 8 KB
If you don’t have java, install it by downloading it here: https://www.java.com/nl/download/
When installed, look if the icon of the JNLP file changes to a java icon. If so, double press the icon and it should start a program.
If you still get the unrecognized extension error you need an extra thing to do. To open a JNLP, javaws.exe is used. This can be found in the bin folder where you installed java. An example location is: C:\Program Files\Java\jre7\bin\javaws.exe
So you can do 2 things here:
- Open it through your terminal
- Choose a default application to open a JNLP file
1. Run your JNLP file through the terminal
Execute the following command in your terminal:
"C:\Program Files\Java\jre7\bin\javaws.exe" myfile.jnlp
2. Select javaws as default application for JNLP files
- Right click on your JNLP file
- Select “open with”
- Select “choose another app”
- Go to your javaws.exe directory and select javaws.exe
- Make sure you enable “Always use this app to open .jnlp files”
Now the JNLP file’s icon should change to a java icon. Now double click the JNLP file and it should run.