Web Services

The Web Services accepts HTTP requests, and responds with XML data. The interfaces then parse this data for presentation. Parameters are either passed in the URL or form encoded. The services available are split into four categories:

• User Resources – Allows the creation and management of a user, such as adding a list, reminders or trusted users.
• List Resources – Allows the creation and management of a list, such as adding items.
• Item Resources – Items can be created, deleted and checked out.
• Shop Resources – Shop layouts can be added, modified and deleted.

The Web Services were created using JAX-RS which allows the creation of Web Services using annotations. A sample method is given below.

@HttpMethod(value = "GET")
@ProduceMime(value = "application/xml")
@UriTemplate("User_Details")
public String User_Details(@QueryParam("UserId") int UserId) {

@HttpMethod – Defines what HTTP type the service should respond to, such as GET or POST.
@ProduceMime – What the response type will be such as plaint text or XML.
@UriTemplate – What URI the service should respond to.
@QueryParam – The name of the parameter sent with the URI

Web Server

Jakarta Tomcat manages the connections to the database by:

• Managing the connection pooling.
• Monitoring for abandoned database connections and closing them.

Requests are handled by servlets. Each request is mapped to a servlet, which creates a new thread to process it.

Database

The backend uses mySQL, a freely available open source database. Each major entity in the system is mapped to a table as well as intermediary tables to link entities together.

• Users
• Lists
• Items
• Reminders
• TrustedUsers
• Shops
• Layouts