How to decompose a URL into its component parts in Java?

Question

My requirements are pretty simple, but I have a lot to do, so I'm looking for a reliable solution.

Is there a good lightweight library for decomposing URLs into their component parts in Java? I mean hostname, query string, etc.

Answer 1

Take a look at java.net.URL . This has methods for exactly what you are trying to do.

Host Name: getHost()
Query string: getQuery()
Snippet / ref / anchor: getRef()
Path: getPath()

Answer 2

I always forget the URI format, so here it is:

 <scheme>://<userinfo>@<host>:<port><path>#<fragement> 

And here is an example:

 URI uri = new URI ("query:// [e-mail] :9000/public/manuals/appliances?stove#ge"); 

The following will happen:

• uri.getAuthority() will return " [e-mail] :9000"
• uri.getFragment () will return "ge"
• uri.getHost () will return "books.com"
• uri.getPath () will return "/public/manuals/appliances"
• uri.getPort () will return 9000
• uri.getQuery () will return "stove"
• uri.getScheme () will return "query"
• uri.getSchemeSpecificPart () will return "// [e-mail] :9000/public/manuals/appliances?stove"
• uri.getUserInfo () will return "jeff"
• uri.isAbsolute () will return true
• uri.isOpaque () will return false

I found this blog handy: Exploring Java APIs: URIs and URLs

Answer 3

java.net.URI and java.net.URL do not work for many modern URLs. java.net.URI adheres to RFC 2396, which is a really old standard. java.net.URL sometimes does a good job, but if you work with URLs found in the wild, this will fail for many cases.

To solve these problems, I wrote galimatias , a library for parsing and normalizing URLs for Java. It will work with almost any URL that you can imagine (basically, if it works in a web browser, the galimates will analyze it correctly). And it has a very convenient API.

You can get it at: https://github.com/smola/galimatias

Answer 4

Look at the getter methods of the class.

You have everything you need.

Answer 5

 URL.getProtocol() URL.getHost() URL.getPort() 

And so on.