Question

I would like to ask if there’s any Java package or library that have the standard URL normalization?

5 Components of URL Representation

http://www[dot]example[dot]com:8040/folder/exist?name=sky#head

1. scheme: http
2. authority: http://www.example.com:8040
3. path: /folder/exist
4. query: ?name=sky
5. fragment: #head

The 3 types of standard URL normalization

Syntax-Based Normalization

• Case normalization – convert all letter at scheme and authority components to lower case
• Percent-encoded normalization – decode any percent-encoded octet that corresponds to unreserved character, such as %2D for hyphen and %5 for underscore
• Path segment normalization – remove dot-segments from the path component, such as ‘.’ and ‘..’

Scheme-Based Normalization

• Add trailing ‘/’ after the authority component of URL
• Remove default port number, such as 80 for http scheme
• Truncate the fragment of URL

Protocol-Based Normalization

• Only appropriate when the results of accessing the resources are equivalent
• For example, example.com/data is directed to example.com/data/ by origin server

Answer 1

URI uri = URI.create("http://www.example.com:8040/folder/exist?name=sky#head");
String scheme = uri.getScheme();
String authority = uri.getAuthority();
// ...

https://docs.oracle.com/javase/1.5.0/docs/api/java/net/URI.html