Modifying a File Inside a Jar

Modifying a file inside a jar

You can use the u option for jar

From the Java Tutorials:

jar uf jar-file input-file(s)

"Any files already in the archive having the same pathname as a file being added will be overwritten."

See Updating a JAR File.

Much better than making the whole jar all over again. Invoking this from within your program sounds possible too. Try Running Command Line in Java

How can I modify a text file inside a Jar file while runtime?

You can't change any content of a jar which is currently used by a jvm. This file is considered locked by the operating system and therefore can't be changed.

I suggest to write this file outside your jar file. e.g. in a /conf directory relative to the current working dir.

Modify information inside jar file

I would recommend having an external text file stored somewhere relative to your program. Then have your program modify it as it needs.

How do I update one file in a jar without repackaging the whole jar?

-C is changing the local directory, and is looking for hi.png there. It's not controlling where you're trying to inject it into the JAR file.

I would try making a new directory called images, moving your local hi.png into that, making images a child directory of your current working directory, then just run this:

jar uf myfile.jar images\hi.png

Edit the .properties file inside a jar without extracting it or changed to .zip format

JAR files are built on the ZIP file format and have the .jar file extension. you can create or extract JAR files using the jar command that comes with a JDK. You can also use zip tools to do so;

You have to know that JAR files - like any other ZIP files is in compressed format. You cannot update a file inside a zip archive without extracting it and putting it back to the archive,no matter what tool may you use (Zip,WinRar,7-Zip or jar) you are just extracting the file and editing and then putting it back to the archive.The below given answers are also doing that,but the file are being extracted to a temporary directory and you are not seeing it.

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