Eclipse Neon unable to view jar file in package explorer

Question

I am unable to browase and view content of jar files in package explorer in Eclipse Neon.

Now everything I've seen says that Package Explorer will allow me to view the contents of a Jar file. My experience with previous versions of Eclipse confirm this as does this Neon site http://help.eclipse.org/neon/index.jsp?topic=%2Forg.eclipse.jdt.doc.user%2Freference%2Fviews%2Fref-view-package-explorer.htm.

However this screen fragment shows that the jar file doesn't have the arrow icon that indicates it can be expanded and browsed in Package Explorer

I've recently moved from Mars to Neon so I'm wondering what gives here. This is very annoying but every answer says "just use package explorer view".

Is your jar part of the Referenced Libraries? If yes, can you browse it from there? — Mickael
No it isn't. I can browse the jar file that is in the Referenced Libraries — mister270

greg-449 greg-449 · Accepted Answer · 2016-09-06T06:59:32

Package explorer will only let you look in jars which have been processed as part of compiling your code.

So in an ordinary Java project this will be the jars in the 'Referenced Libraries' section and the 'JRE System Library'.

For plugins the 'Plug-in Dependencies' and 'External Plug-ins' are also included.

You can add the library to your project's classpath temporarily to allow you to look at contents.