add custom attribute or metadata to file java

Question

I have files that need an extra attribute called \"encryption used\". But this gives \"IllegalArgumentExeption\". I know why it gives that error, \"encryption used\" isn\'t

Answer 1

If your file system supports user-defined (aka extended) attributes, then the way to set one would be like this:

Files.setAttribute(path, "user:encryption used", "testtesttest");

As the javadoc for setAttribute explains, the 2nd argument takes the form of an optional view-name and an attribute name. In this case, you need to use the UserDefinedFileAttributeView whose view-name is "user".

Note that different file system types support different attribute views, and your file system may not support this one.