when I tried to create a new alfresco project with maven there is 3 types of projects alfreco share amp archetype project ,alfresco amp project archetype and alfresco allinone archetype project . What is the difference between them ?
The alfresco amp project archetype is for generating projects that create a "repo tier" AMP file. The resulting AMP file is meant to be installed into the Alfresco WAR file.
The Share amp project archetype is for generating projects that create a "Share tier" AMP file. The resulting AMP file is meant to be installed into the Share WAR file.
The all-in-one archetype creates a project structure that will give you everything a running Alfresco server would need, including solr. The output of building a project instantiated with this archetype will be a repo tier AMP, a Share tier AMP, an Alfresco WAR, and a Share WAR.
Which should you use?
That depends. On most of my projects, even of moderate complexity, I prefer the flexibility of having independent projects for the repo tier and Share tier. I don't need or want the added overhead (and build time) that comes with the all-in-one archetype.
For some projects, especially where solr is going to be very important, or if my project is going to depend on several other AMPs, the all-in-one project makes sense.
It's really a personal preference.
For more information on the SDK, consider reading my tutorial.