Java URI doesn't encode semicolons in path. Best practice here?

Question

I'm working on a project where a local file is exported via HTTP. This involves getting a file URI, relativizing it using the exported path, tacking it onto the export URI and then handling that as a URL on the receiving end.

Normally this works fine, but I run into trouble when the filename contains a semicolon. I narrowed it down to here:

new File(path).toURI()

The above method correctly encodes spaces and the like, but not semicolons (which should be encoded into a %3B).

Ultimately the above method returns the result of the URI constructor (protocol, host, path, fragment), which returns the bad URI.

I could manually replace all semicolons with %3B, but that doesn't feel like the best solution. Is there really no built-in API to correctly encode a path?

Many thanks for any assistance.

Answer 1

The reason semicolon is not escaped automatically is because it has a meaning in the URI specification - it delimits "path parameters". The following URI si valid: /some;a=b/path

and represents path /some/path with a path parameter a of value b.

So in this case the escape must be manual, because URI cannot determine whether the semicolon delimits parameters or is part of the path.