What is the proper way to parse the entries of a manifest.mf file in jar?

Question

The manifest.mf contained in many Java jars contains headers which look much like email headers. See example [*]

I want something that can parse this format into key

Answer 1

MANIFEST.MF files can be read with the Manifest class:

Manifest manifest = new Manifest(new FileInputStream(new File("MANIFEST.MF")));

Then you can get all entries by doing

Map<String, Attributes> entries = manifest.getEntries();

And all main attributes by doing

Attributes attr = manifest.getMainAttributes();

A working example

My MANIFEST.MF file is this:

Manifest-Version: 1.0
X-COMMENT: Main-Class will be added automatically by build

My code:

Manifest manifest = new Manifest(new FileInputStream(new File("MANIFEST.MF")));
Attributes attr = manifest.getMainAttributes();

System.out.println(attr.getValue("Manifest-Version"));
System.out.println(attr.getValue("X-COMMENT"));

Output:

1.0
Main-Class will be added automatically by build