How to open a JAR file using the command line
You can extract a JAR file to find out what it contains, but you can also view its contents first so you know what files it will create.
A JAR file bundles multiple files and folders into a single file. From time to time you may need to check the contents of your JAR file.
There are two main ways to discover the contents of a JAR file. These methods are platform independent, so you can use them on Linux, Windows, or macOS.
Why might you need to explore a JAR file?
A situation may arise when you want to check the contents of a JAR file. You may want to update it or upload the file to the web once you verify what you are sending.
The jar The tool offers you two ways to explore your JAR archive. The first method is to view the content without extracting it. The second method is to extract the contents of the JAR file to a file system.
Viewing the contents of a JAR file
In its simplest form, you can use jar to open a JAR file like this:
jar tf YourJarFile.jar
The you The option tells the jar tool to generate a table of contents. The F the option tells jar to open a file rather than reading an archive from standard.
The order in which you specify these options does not matter. However, you need to make sure there is no space between them.
The example above assumes that your JAR file is in the current working directory. If not, you can specify the file path instead of just the file name.
To view more details about a JAR file, like creation date, you can use the detailed option, v.
jar tfv YourJarFile.jar
You can extract the contents of a JAR file using a command like this:
jar xf YourJarFile.jar
The X The option instructs the jar tool to extract the contents of the archive. This command will copy the contents of the JAR file to the current directory. It will match the directory structure of the items in the JAR file.
You may want to extract particular items from your JAR file rather than the entire contents. In this case, you can indicate these elements after the name of the JAR file:
jar xf YourJarFile.jar login.html payment.html
This command will extract two HTML files from the JAR file, if they exist inside.
Use a graphical approach
Sometimes you might prefer to use a GUI tool instead of the command line. In this case, you can opt for a GUI-based tool to open your JAR file. There are several such programs that you can use on Windows 10.