If you have a JAR ("Java archive") file and wish to extract the files contained within it from a command-line interface (CLI) on a Microsoft Windows system, you can do so by opening a command prompt window and using the
jar xf filename.jar command,
where filename.jar is the relevant .jar file, if you have
the Java
Development Kit (JDK) installed on the system — the JDK software
can be downloaded for free from Oracle's
Java Downloads
page.
Minecraft uses
.jar files for mods and if you wish to view the models (.json files), textures
(.png files) within a JAR file used by Minecraft, you can use the
jar xf filename.jar command to see those. If you
copy the .jar file to a directory where you wish to extract its contents
and then run the command from the directory in which the .jar file is located,
you should see a directory named assets appear beneath which you
can find blockstates, lang, models, and
textures subdirectories.
The .json files files, such as those you may see in a models/block
subdirectory are
JavaScript Object Notation (JSON)
files, which you can view or edit in a text editor, such as the
Windows Notepad
application. The .png files, which you may see in a textures
subdirectory are Portable Network Graphics (PNG) files, which you can
view or edit in graphics applications such as
Microsoft Paint
on Microsoft Windows systems. You can also use a tool such as
Blockbench to work with the
JSON model files and PNG images.
