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Application Handlers

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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"]}}

Chosen solution

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)

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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)

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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"..?

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> 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?

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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

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Chosen Solution

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

And yeah, those should definitely work for jnlp.,

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Thank you so much, Mike!