Oracle ATG Interview Questions and Answers

ATG is a framework for creating web applications. It is based on J2EE standards.

The core of the ATG platform is:

DAF or Dynamo Application Framework, which implements a component development model based on JavaServer Pages (JSPs) and JavaBeans.

Basically, a droplet is an ATG’s custom servlet which has some atg-specific customization. It can be correlated with the HttpServlet in J2EE, but here we use DynamoServlet class which implements javax.servlet.Servlet interface in ATG.

Droplets are mainly used to abstract out the business logic in server-side code.

In ATG a component is simply is a configuration file (a simple text file with. properties extension), which uses a java class.

In ATG, Nucleus is referred to the ATG container for components.  It provides an hierarchical name space to component. Each component has a unique full name so that pages and other components can reference it.

Scope is nothing but a nucleus variable, which tells the nucleus till when a component will exist.

You can create a JSPs in ATG or JSP page is processed in ATG by following steps:

• User access the browser, type a URL and send a request for a JSP to ATG application
• ATG application receives the request for the JSP file you requested
• Once the JSP is found it is compiled into JAVA code
• When all the content is fetched by the Java code, the end result is converted into plain HTML
• This HTML page is sent back to the browser
• This is how the JSP page is processed in ATG application.

The types of request handling pipelines used by Dynamo

• DAS Servlet pipeline: It is used to handle JHTML request
• DAF Servlet Pipeline: It is used to handle the JSP request

The default scope of a component is Session.

The two methods in a component are: getters & setters

The difference between FormHandler, droplet and servlet:

• FormHandlers are used when there are forms. They help to perform validation for the forms.
• Droplet is from ATG, and it is used to put or render data in the database.
• Servlet is used to submit data, it acts as a controller. It is not used to put data.

• It is used to deal huge data
• It can write any object of type 1 call in to the db.
• Dynamo messaging using patch bay and jms
• Dependency injection

The performance issues with ATG include:

• High levels of database activity
• CPU utilization problems
• long running SQL queries
• Slow response times

The two types of cache that ATG repository maintains:

• Item Cache
• Query Cache

ATG DPS is referred to ATG Dynamo personalization system. The key elements of ATG are:

• User Profile Management
• Content Targetting
• Targeted E-mail

The scope of Dynamo Components is:

• session
• request
• Global
• The default scope is Global

The main difference between JSP and DSP tag libraries are:

• Dsp is a ATG specific tag libraries that involves in executing only DAF framework resources. Also, Dsp imports all objects of type class.
• JSP involves in all the functionalities for web application development. Also, Jsp imports only the primitive data types.

If the ATG applications are deployed on a cluster of servers then it is better to go for either Distributed caching or Locked caching.

DSP tags: DSP tag library tags support runtime expressions. These tags use an id attribute to name the scripting variables they create.

DSPEL tag: DSPEL tag library tags support JSTL Expression Language (EL) elements that are also evaluated at runtime.

The standard atg.repository.QueryBuilder interface defines available query operations that repositories should support.

The advantage of Nucleus in ATG are:

• It renders a simple way to write new components
• In nucleus, applications don’t need to contain code to create instances of components. It is created and administered through configuration files
• By organizing configuration files into layers Nucleus provides a convenient way to modify and extend component properties
• Nucleus provides a large number of out-of-the-box generalized service components
• Nucleus makes it easy for application developers to set the scope of their components.

we can create it in 2 ways:

• using ACC
• by creating java+properties file in our module/Eclipse

DAS DPS DSS DCS: from left to right

We maintained it in MANIFEST.MF file

Manifest-Version: 1.0

ATG-Config-Path: config/

ATG-Required: DAS DPS DSS DCS DAS

ATG-J2EE: j2ee-apps/testJ2ee

ATG-EAR-Module: j2ee-apps/testJ2ee

ATG-Class-Path: bin

Mainly used in my application level:

• CartModifierFormHandler
• PaymentGroupFormHandler
• ShippingGroupFormHandler
• CommitOrderFormHandler
• GenericFormHandler
• ProfileFormHandler

array,elementName,indexName.