URN and URL

[Former Member]

What is the difference between URN and URL.

Where we use this.

Please be clear.

[Former Member]

What is an URL

An Uniform Resource Locator (URL) is the term used to identify an Internet resource, and can be specified in a single line of text.

What is an URN

An Uniform Resource Name (URN) is the term used to identify an Internet resource, without the use of a scheme, and can be specified in a single line of text.

What is an URI

An Uniform Resource Identifier (URI) is used by a browser to identify a single document, and it too can be specified in a single line of text

The general form of an URL has four parts

A scheme followed by a colon.

Invokes a TCP/IP-based application level protocol

Schemes are: http, https, ftp, news, mailto, file, telnet.

A server name.

A // followed by the host name or IP address of the server

Not needed if the server is the default

news server

mail server

An optional port number. Standard or default port numbers are:

ftp *

ssh 22

telnet 23

smtp 25

gopher 70

http 80

nntp 119

SSL 443

A path.

Consisting of folders and/or files.

May include a file extension which identifies the type of document.

May also include a QUERY_STRING with arguments.

Ftp uses port 20 for data and port 21 for flow control.

DIFFERENCE BETWEEN URN & URI

The idea is that a URL is a mechanical link to a resource's location, where it can be downloaded. For this reason, a URL contains a hostname and a local part, all of which can be resolved anywhere on the Internet.

What a URN tries to do is different. It tries to give a description of a resource without actually pointing at it. For example:

urn:isbn:90-365-17273

-

---

URI: is a string that identifies any resource. Indentifying the resource does not necessarily mean we can retrieve it. URI is a superset of URL and URN.

files/reports/marketing/report.html

URL: URI that specify a common Internet protocol such as HTTP or FTP are also called URLs. URL is an informal term an is not used in technical specifications.

http://www.foo.com/files/reports/marketing/report.html

URN: A URN is an identifier the uniquely indentifies a resource but does not specify how to access that resource.

ISBN: 1-930110-59-6

I hope it helps

Best Regards

chandrakanth

[Former Member]

URL starts with http://

When you specify an HTTP address as a namespace this does not mean that you can access additional information about the namespace from this address (in some cases an XML schema definition is hidden behind the address). The HTTP address used merely ensures that the name of the namespace is unique. SAP namespaces adhere to the standard http://sap.com/xi/<Name>.

URN starts with urn:

Namespaces with this prefix have no value in the sense that they are not connected with a Web page in the Internet.

It is assumed that conventions ensure that namespaces are unique.

Gaurav Jain

Points if answer is useful

[Former Member]

Hi,

URL : For web based applications we use URL like webservicess applications.like webservicess,...

URN : Other than Webservicess applications we can use the URN. like file, ...

Internal process is same.

[Former Member]

Hi,

The namespace could be any string that uniquely defines the scope of those determined fields of the XML file. Usually, you use a URI to define that unique string, and since URLs are the most common URIs, people tend to use plain http URLs as the namespace (it doesn't need to be a valid url). But using "urn:test" for example isn't wrong.

From the specification:

URI

URI = Uniform Resource Identifier

There are two types of URIs: URLs and URNs

URL

URL = Uniform Resource Locator

<protocol>:// <host> :<port> [<path> ? <query>]

URN

URN = Uniform Resource Name.

URNs define XML schemas.

urn:<namespace>:<string>

URL: URI that specify a common Internet protocol such as HTTP or FTP are also called URLs. URL is an informal term an is not used in technical specifications.

http://www.foo.com/files/reports/marketing/report.html

URN: A URN is an identifier the uniquely indentifies a resource but does not specify how to access that resource.

ISBN: 1-930110-59-6

Where we use this

This is used in XI as a way to group your developments. Each Software Component Version can have several namespaces. These namespaces can be of the format

http://sap.com/namespace1

or

urn:sap.com.namespace2

This allows you to give objects the same names if they are in different namespaces as they can still be differentiated.

Also all development objects must belong to a specific namespace.

Please reward points if it helps

Thanks

Vikranth