Is it possible to see who has accessed a document just for reading.And if so how is it done?
By default there is no acces auditing. You can enable the alfresco-access audit application, which will audit every modification to a document, as well as read access on its content (note: only download of the file or access to its preview are logged, so in somce cases you might not see a "READ" event if a user checks the docment via the web interface or APIs, when it isn't accompanied with a successful access to the preview/content as well). You can query the data collected by alfresco-access via the AuditService (Java API), which you can use in a custom web script to load the audit trail of a specific document. AFAIK Alfresco Records Management already provides an out-of-the-box action for accessing the audit trail of a record. Something similar could be build quite easily for an application using only ACS.
Retrieving data ...