Unstructured Content 
Use
The data that a resource contains is referred to as its content. The repository framework handles the content as a java.io.InputStream and simply passes it on to the responsible repository. It has no knowledge of the content itself. For this reason, the content is called unstructured content.
Features
Although the content itself is unknown, metadata about the content exists. The metadata describes the content similarly to an HTTP MIME header. Metadata is only available for a resource if the original object, which is stored in the backend system, is able to provide metadata for the repository manager.
To see the detailed specification of the metadata, search the Internet for the RFC references specified below.
The list below describes the metadata that is defined for content. If an RFC is specified, you can search for it on the Internet to get a detailed specification.
● Content length indicates how many bytes of data the content contains. If the value is –1, the length is unknown to the repository (see RFC2616, section 14.13).
● Content type returns the MIME content type of the data if known to the repository. For example, text/html or text/plain (see RFC2616, section 14.17)
● Content encoding specifies the code that is used to encode the content if known to the repository. For example, UTF8.
● Content language specifies the language if known to the repository. For example, en (see RFC2616)
● Entity tag (ETag) indicates changes to resources if known to the repository. A weak ETag, which has the prefix W/, shows that the content of a resource has changed in a semantically significant way. A strong ETag shows that a resource has changed in some way (see RFC2616, section 14.19)
● Expires field specifies the timestamp when the content expires if known to the repository. For example, Thu, 10 Jul 2003 10:00:00. (see RFC2616, section 14.21).
● Last modified specifies the timestamp when content or properties were last modified, for example, Fri, 11 Jul 2003 11:00:00. (see RFC2616, section 14.29).
See also: