Invalid characters for http URL

Question

Can anyone tell me what are the invalid characters for HTTP URL and the best way to validate the same in Java. What I am looking for is URLString validation in the URL format: http(s)://ip:port/URLString

Thanks in advance.

score 4 · Answer 1 · edited Oct 07 '21 at 05:57

You can use any unicode characters you want, as long as they are % encoded. The explicitly reserved characters are defined in section 2.2 of RFC3986: https://www.rfc-editor.org/rfc/rfc3986#section-2

From the document:

  reserved    = gen-delims / sub-delims

  gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"

  sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
              / "*" / "+" / "," / ";" / "="

score 1 · Accepted Answer · edited May 23 '17 at 12:15

According to RFC 1738 the following are deemed unsafe:

< and > - delimiters around URLs in free text
" (double quote) - delimits URLs in some systems
- delimits a URL from a fragment/anchor identifier that might follow it
% - used to indicate character encodings

General unsafe characters: { } | \ ^ ~ [ ] `

Edit:

Not a duplicate, but includes some thoughts on validation in Java: Validate URL in java

score 0 · Answer 3 · answered Jun 24 '11 at 05:34

0

Read RFC1738 Page 2 and Page 3 on the link for details.

answered Jun 24 '11 at 05:34

phoxis

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score 0 · Answer 4 · answered Jun 24 '11 at 05:42

0

How about using UrlValidator ? isValidPath method probably useful. :)

answered Jun 24 '11 at 05:42

mattn

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Invalid characters for http URL

4 Answers4

- delimits a URL from a fragment/anchor identifier that might follow it