This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

ابحث في الدعم

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Application Handlers

more options

Hi All, I have been on the struggle bus lately trying to get the application handlers set properly in our GPO. I am trying to get PDF, webp, avif to open in browser, and jnlp to auto launch Java. Any help will be greatly appreciated!

{"application/pdf":{"action":3,"extensions":["pdf"]},"image/webp":{"action":3,"extensions":["webp"]},"image/avif":{"action":3,"extensions":["avif"]},"application/x-java-jnlp-file":{"action":4,"handlers":[{"name":"javaws.exe","path":"C:\\Program Files (x86)\\Java\\jre-1.8\\bin\\javaws.exe"}],"extensions":["jnlp"]}}

Hi All, I have been on the struggle bus lately trying to get the application handlers set properly in our GPO. I am trying to get PDF, webp, avif to open in browser, and jnlp to auto launch Java. Any help will be greatly appreciated! {"application/pdf":{"action":3,"extensions":["pdf"]},"image/webp":{"action":3,"extensions":["webp"]},"image/avif":{"action":3,"extensions":["avif"]},"application/x-java-jnlp-file":{"action":4,"handlers":[{"name":"javaws.exe","path":"C:\\Program Files (x86)\\Java\\jre-1.8\\bin\\javaws.exe"}],"extensions":["jnlp"]}}

الحل المُختار

Yeah, you shouldn't need to modify anything for the other stuff.

And yeah, those should definitely work for jnlp.,

Read this answer in context 👍 1

All Replies (6)

more options

The actions need to be actual names not numbers.

Have you taken a look at Handlers here?

https://mozilla.github.io/policy-templates/#handlers

Also, JNLP only works on the ESR (long story)

more options

Thank you for that information! So the handler action can be a number in the local Handlers.json in the local profile, but not in the GPO, got it. I guess there is simply not an action for "open in browser" or "handle internally"..?

more options

> I guess there is simply not an action for "open in browser" or "handle internally"..?

Yeah, I figured most of those would just happen by default. Have you found a case where I need to add it?

more options

I'm guessing webp, avif, and PDF are, by default, set to open in browser and my broken policies are changing them to save to file? So I just need to set a GPO handler for JNLP only, I think (I am on ESR102.7) This should work for the JNLP handler GPO, right? Thanks again for your time and support!!!

{

 "mimeTypes": {
   "application/x-java-jnlp-file": {
     "action": "useHelperApp",
     "ask": false,
     "handlers": [{
       "name": "Java(TM) Web Start",
       "path": "C:\\Program Files (x86)\\Java\\jre-1.8\\bin\\javaws.exe"
     }]
   }
 },
 "extensions": {
   "jnlp": {
     "action": "useHelperApp",
     "ask": false,
     "handlers": [{
       "name": "Java(TM) Web Start",
       "path": "C:\\Program Files (x86)\\Java\\jre-1.8\\bin\\javaws.exe"
     }]
   }
 }

}

Modified by Chris Wilkerson

more options

الحل المُختار

Yeah, you shouldn't need to modify anything for the other stuff.

And yeah, those should definitely work for jnlp.,

more options

Thank you so much, Mike!