ATG Interview Questions and Answers

1.What is ATG?

Ans:

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

2.Mention what is the core of ATG?

Ans:

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.

3.What is a droplet in ATG?

Ans:

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.

4.What is a component in ATG?

Ans:

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

5.What is the Atg Pipeline?

Ans:

Atg Pipeline is a variant of Servlet Pipeline, In an ATG pipeline the sequence of Programs are executed in a queue.

Below is the ATG servlet pipeline

• /atg/dynamo/servlet/pipeline/DynamoHandler
• /atg/dynamo/servlet/pipeline/TransactionServlet
• /atg/dynamo/servlet/pipeline/PathAuthenticationServlet
• /atg/dynamo/servlet/pipeline/URLArgumentServlet
• /atg/dynamo/servlet/pipeline/CookieServlet
• /atg/dynamo/servlet/pipeline/ContextPathServlet
• /atg/dynamo/servlet/pipeline/ServletPathServlet
• /atg/dynamo/servlet/pipeline/SessionServlet
• /atg/dynamo/servlet/pipeline/DynamoServlet
• /atg/dynamo/servlet/pipeline/SessionSaverServlet
• /atg/dynamo/servlet/pipeline/FormLoginServle
• /atg/dynamo/servlet/pipeline/WebApplicationDispatcherServlet
• /atg/dynamo/servlet/pipeline/CgiServlet
• /atg/dynamo/servlet/pipeline/ServletPathDispatcher
• /atg/dynamo/servlet/pipeline/FileFinderServlet
• /atg/dynamo/servlet/pipeline/MimeTyperServlet
• /atg/dynamo/servlet/pipeline/MimeTypeDispatcher
• /atg/dynamo/servlet/pipeline/FileServlet

It starts with the DynamoHandler which adds the Dynamo specific request and response objects to the request’s context. Actually the list of servlets you will see depends on which modules you have running. This is the DAS configuration DPS and other modules can and do add more servlets to the pipeline.

6.What is the ATG component scope?

Ans:

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

7.What is ATG DPS?

Ans:

ATG DPS refers to the ATG Dynamo personalization system. It is driven by User Profile Data and business rules designed to deliver the right content to the right user.

8.How can you create a JSPs page in ATG or a JSP page that is processed in ATG?

Ans:

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 an ATG application.

9.Mention what are the types of Pipeline in ATG?

Ans:

The types of request handling pipelines used by Dynamo

DAS Servlet pipeline – It is used to handle HTML request

DAF Servlet Pipeline – It is used to handle the JSP request

10.Mention what is the default Scope of a Component?

Ans:

The default scope of a component is Session.

11.Mention what are the two methods in a component?

Ans:

The two methods in a component are getters & setters

12.Mention what is the difference between FormHandler, droplet and servlet?

Ans:

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

13.Mention the Advantages of DAF?

Ans:

• 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

14.What are the performance issues with ATG?

Ans:

The performance issues with ATG include

High levels of database activity

CPU utilization problems

long running SQL queries

Slow response times

15.Mention what are the two types of cache that ATG repository maintains?

Ans:

The two types of cache that ATG repository maintains

• Item Cache
• Query Cache

16.What are its elements of ATG DPS?

Ans:

There are three key elements of the ATG DPS personalization System.

1. 1. User Profile Management
2. 2. Content Targeting
3. 3. Targeted Email

17.Mention what the scope of Dynamo Components is.

Ans:

The scope of Dynamo Components are

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

18.Mention what is the main difference between JSP and DSP tag libraries?

Ans:

The main difference between JSP and DSP tag libraries are

Dsp is an ATG specific tag library that involves executing only DAF framework resources. Also, Dsp imports all objects of type class.

JSP is involved in all the functionalities for web application development. Also, Jsp imports only the primitive data types.

19.What if the ATG applications are deployed on a cluster of servers?

Ans:

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

20.Mention what is the difference between dsp and dspel tags?

Ans:

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.

21.Mention what the standard atg.repository.QueryBuilder interface defines?

Ans:

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

22.Mention what is the advantage of Nucleus in ATG?

Ans:

The advantage of Nucleus in ATG are,

It renders a simple way to write new components

In the 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

23.How can you embed the output of a Java servlet (an ATG servlet bean. in a JSP?

Ans:

In order to embed the output of a Java servlet (an ATG servlet bean. in a JSP you need to add dsp:droplet tag with a bean attribute.

24.Mention in order to use custom ATG servlet beans with the ATG Control Center what is required?

Ans:

In order to use custom ATG servlet beans with the ATG Control Center you need to apply following requirements:

You must make a BeanInfo file that defines the servlet bean’s parameters

The class must extend atg.servlet.DynamoServlet

25.What is a Nucleus in ATG?

Ans:

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

26.By using what sign in the configuration files does nucleus properties are processed?

Ans:

The nucleus properties are processed by using the $ sign in the configuration files.

27.What is Nucleus?

Ans:

Nucleus is ATG`s open Object Application Framework. ATG 7 is said to be a component-centric development platform. The ATG 7 Web applications are nothing but individual JavaBean components assembled together. These JavaBean components are configured and linked together by .properties files within Nucleus.

In Nucleus, each service is packaged as a JavaBean or set of JavaBeans. These JavaBeans are configured individually and mounted into a namespace. The beans then interconnect with the beans representing other services. Nucleus is responsible for interpreting the component configurations and the management of the component namespace.

Dynamo uses the Nucleus framework to organize components into a hierarchical structure (similar to a directory structure). Each Nucleus service has a unique Nucleus name. For example, the default javax.sql.DataSource component is located at /atg/dynamo/service/jdbc/JTDataSource

Nucleus is the core of the entire ATG system. It creates and configures Nucleus components (also called beans and JavaBeans) and organizes them into a hierarchical namespace, essentially giving them a place to live so they can be referenced by other components. By reading the .properties files associated with each component, Its Nucleus which figures out which components are to be used in an application ,initializes them to their default values and decides about how they connect to each other. This model makes it easier for the developers to build ATG applications by configuring and using the pre-built components instead of writing a lot of Java code from scratch.

28.What is ATG Repository?

Ans:

ATG Repository refers to the ATG`s way of accessing the Database through programs. It is somewhat similar to what Hibernate offers, Separating the Application Logic from that of Database. So Atg repository provides a fine grained abstraction between the application logic and Database. Thus it supports the ATG`s Data Anywhere paradigm, the application logic created by developers to interact with data need not change for any change in the source of that data. ATG repository architecture ensures that the source of the data is hidden behind the Dynamo Repository abstraction. It would be easy to change from a relational data source to another or to an LDAP directory since none of the application logic would need to change. Once data is retrieved from a data source it is transformed into an object-oriented representation. Manipulation of the data can then be done using simple getPropertyValue and setPropertyValue methods. The Repository API ties in closely with ATG’s targeting APIs, so you can retrieve items from the repository based on a variety of targeting rules, as well as retrieving specific identified items.

29.What is class Hierarchy for ATG Form Handlers?How to create a FormHandler?

Ans:

At the top of ATG formhandler class hierarchy there exists the DropletFormHandlerinterface. Then come, three different classes provided by Dynamo which extend this interface. They are as below

• atg.droplet.EmptyFormHandler
• atg.droplet.GenericFormHandler
• atg.droplet.TransactionalFormHandler

The EmptyFormHandler is the simplest to implement. It implements the DropletFormHandler interface and defines blank body implementations of the methods in this interface.

GenericFormHandler extends EmptyFormHandler. It defines the simple implementations of the DropletFormHandler interface’s methods and the basic error handling logic. If errors occur in processing a form that uses GenericFormHandler, the errors are saved and exposed as properties of the form handler component. TransactionalFormHandler extends GenericFormHandler, It treats the form processing operation as a transaction. Though the methods invoked by this form handler are processed discreetly, their results are saved simultaneously. The beforeGet and afterGet methods do the transaction management. This establishes the transaction before any of your properties are set or handler methods are called.

30.What are ATG Form Handlers?

Ans:

ATG Formhandler is the intermediate class that comes in between a jsp form value and its bean class. They are there to evaluate the validity of form data before it is submitted, write data to and read data from a database or repository, and direct the user to different pages, depending on the results of the form submission

31.How can I resolve/initialize a particular component without injecting in any component.?

Ans:

ATG provides one method resolveName(component name we have to provide) in GenericService class using it we can initialize the component.

32.What are all the input parameters for ForEach Droplet?

Ans:

Array,elementName,indexName.

33.What is User Profile Management?

Ans:

When a person visits a website driven by ATG Dynamo Personalization Server(ATG DPS) website for the first time, The person is allowed to create its own User Profile.

Once created, DPS stores that User`s Profile in its database repository. This profile contains a list of properties that describe the person’s characteristics, such as the name they entered in a registration form or the date of their last login. ATG DPS uses this profile information stored in its database repository to provide targeted content to each other.

34.Define Atg Framework?

Ans:

The ATG framework is used for building Web applications which can run on JBOSS, WebLogic, WebSphere and other J2EE application servers.

35.Explain The Atg Performance Issues ?

Ans:

Performance problems come in many shapes and sizes, but they all mean that the processing of some task is not happening at the expected, and previously observed speed. Performance issues include CPU utilization problems, slow response times, high levels of db activities, SQL queries that run long time, Slow CA deployments, just to name a few.

36.What Is Config Layering?

Ans:

Properties set in later entries in the CONFIGPATH override earlier entries. By adding an entry to the config path you can customize any components in the system without losing the original configuration information.You can have a global configuration common to all machines then have machine specific information in the last layer.

37.What Is A Context Root?

Ans:

Is a URL mounting point of the web application. It decides what URL site site visitors will enter to get to the site. 

“context-root” is specified in the “application.xml” file in the “j2ee-apps” folder.

38.Name 7 Common Elements A User May See During Checkout Through Atg Dynamo?

Ans:

Add to shopping cart, Login, Billing address, Payment, eMail confirmation, Confirm button, Shipped eMail address

39.Differentiate Global,request & Session Scopes?

Ans:

Global: components are accessible from all other components.Not available across ATG servers, each server has its own copy of the global scoped component.

Session: every user of the application gets a separate copy of the component, and the component exists for the duration of the user’s session.

Request : A component is called in for returning the values of a search, so each time a search is triggered an object instantiation happens and it’s gone when the result page is closed.Which me the scope of the search component is requested.

Eg:-form handlers normally have a request scope.

40.What Is Atg Nucleus?

Ans:

Nucleus is an ATG container for components. It creates and initializes component instances on request. It manages the components scope. It locates the properties file for the component and through that it reaches the class file of the component. Nucleus components are Java Objects each with an associated .properties file which store configuration values.

41.What Is Base Class For All Atg Formhandlers?

Ans:

GenericFormHandler.java

42.How We Can Achieve Inheritance In Atg Repository Level?

Ans:

• sub-type-property=”type”
• super-type=”super item”

Ex :

Here hardgoodShippingGroup is the subitem(like class) shippingGroup is the super Item(class)

Hence all the features/properties of shippingGroup we can get it in hardgoodShippingGroup item also.

43.Differences Between The Item-type And Component-item-type In Definition(xml)file?

Ans:

When your property in the item-descriptor needs to hold only one value which is of type of any other repository item, use ‘item-type=”item name”’ attribute.

when your property needs to hold a collection (set/array/map/list) of items of type of any other repository item,use data-type = “set/array/map/list” and component-item-type=”another Item name” to specify what type each one of the element in the collection

44.Explain Logging Features Of Atg?

Ans:

Any component whose base class implements “ApplicationLogging” Interface can use atg logging infrastructure. Logging can be done per-component, per-module/per-application basis. Error, Warning,Info & Debug messages are the various logging mechanisms.First three are logged by default, whereas the Debug messages are just for debugging purpose and should be removed when the code goes into production.Logging is managed using the “GLOBAL.properties” file, which specifies the log levels of various modules.

45.How To Create Components?

Ans:

we can create it in 2 ways:

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

46.What Are Custom Dsp Tags?

Ans:

In general, the Custom tags will be written by the developer.

Dsp is all ready to use. you can use it to render content dynamically by linking Nucleus components directly to your JSPs. Especially the (dsp) tag library, which allows you to connect your JSP content to the Java code at work behind the scenes so you can separate your application logic from your presentation layer.

ATG 7 provides you with three tag libraries: JSTL, DSP/DSPEL, and Core. You can find these tag libraries in /DAS/taglib.

47.What Are All The Ootb Form Handlers You Used In Your Application Tell Me 6?

Ans:

Mainly i used in my application level:

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

48.Which Are The Handlex Methods In ?

Ans:

HandleX methods contain the actual function to be performed. it’s a method. Like in ProfileFormHandler- handleLogin

49.How Can I Resolve/Initialize A Particular Component Without Injecting In Any Component ?

Ans:

ATG provides one method resolveName(component name we have to provide) in GenericService class using it we can initialise the component.

50.Describe The Meaning Of Atg Repository?

Ans:

Using ATG Dynamo, this is the process for entering into a Database using programs while keeping the actual application logic apart from the Database.

51.What Are Derived Properties?

Ans:

Enables one repository item to derive property values from another repository item or from another property in the same repository item.

52.What is Content Targeting?

Ans:

Targeting is the process of displaying

1. 1. Content items
2. 2. To a particular user
3. 3. At a particular time
4. 4. In a particular context and
5. 5. On a particular rule set.

In the DPS rule based system, business managers create rule sets called content targeters that control how content is displayed on the web site.

53.How Connection Will Give From Atg Module To Db?

Ans:

/atg/dynamo/service/jdbc/JTDataSource.properties Using JTDataSource component will maintain the Schema/DB connection.

54.How A Component Is Instantiated ?

Ans:

One can start or stop components manually using an ACC.We can instruct nucleus to start a component during server startup, this is done by modifying the “Initial.properties” file.Add the component name to the “initialServices” property inside the Initial.properties file.

55.Mention what is the standard atg.repository.QueryBuilder interface defines?

Ans:

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

56.When Or In Which Scenario I Will Go For Itemlookupdroplet?

Ans:

To get a complete item by providing id as an input parameter to that droplet.

57.Explain what the ATG component scope is?

Ans:

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

58.Explain how you can create a JSPs in ATG or a JSP page is processed in ATG?

Ans:

• 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 an ATG application.

59.Mention the two methods in a component?

Ans:

The two methods in a component are

getters & setters

60.What is Targeting Email?

Ans:

DPS includes a Targeted Email service for composing and delivering personalized email using the same profile groups and targeting rules you use to deliver content on your web site. Also if you have Dynamo Scenario Server installed, you can use scenarios to deliver targeted email. You can use targeted email to perform below activities.

1. Send a confirmation message to a new user who registers at your site.

2. Notify frequent customers of special sales.

3. Notify all users that have not logged into your site in several months that their accounts will be closed soon.

4. Send out a mass mailing with each message tailored to its recipient.

61.Explain the performance issues with ATG?

Ans:

The performance issues with ATG include

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

62.What Is Atg Tag Library?

Ans:

Atg tag library is a variant of jsp standard tag library. However atg provides its own set of tag libraries e.g. dsp,dspel, core

63.What Is Bcc?

Ans:

Business Control Center- UI for Business Users (to upload content to Catalogs, create promotions etc)

64.How To Register A Repository With The Dynamo?

Ans:

Create “/config/atg/registry/ContentRepositories.properties” file and append our repository file (XML )name to the “initialRepositories” property
Eg: initialRepositories+= /myModule/mySampleRepository

65.Explain how you can embed the output of a Java servlet (an ATG servlet bean) in a JSP?

Ans:

In order to embed the output of a Java servlet (an ATG servlet bean) in a JSP you need to add dsp:droplet tag with a bean attribute.

66.What Is a Manifest File?

Ans:

Applications often depend on other modules, these dependencies are declared in this file.The file name is MANIFEST.MF and resides in the META_INF directory. It specifies ATG-Class-Path,ATG-Required, ATG-Config-Path etc

67.Have you worked with repositories

Ans:

If you answer yes be ready to answer questions on cache, implementing a repository from scratch, and others. (please see my post on repositories)

68.Name 2 types of tables

Ans:

Primary and auxiliary

69.Have you worked on shopping carts

Ans:

CartModifierFormHandler , ShoppingCartFormHandler

70.Name 2 types of checkout

Ans:

Express Checkout, Guest Checkout

71.What Are Different Modes Caching?

Ans:

Caching modes are set at the item descriptor level, through the <item-descriptor> tag’s cache-mode attribute. The default caching mode is simple caching. To set a different caching mode on an item descriptor, set cache-mode to one of the following values: 

• simple
• locked
• distributed (distributed TCP caching)
• distributedJMS (distributed JMS caching)
• distributedHybrid (distributed hybrid caching)

72.Differentiate between dsp and dspel tags

Ans:

The DSP tag library tags support runtime expressions, such as references to scripting variables. These tags use an id attribute to name the scripting variables they create.

The DSPEL tag library tags support JSTL Expression Language (EL) elements that are also evaluated at runtime. These tags often produce a result object named by the var attribute.

For custom tags we need to write the properties file and a class file to define the functions. We need to include a tag file with extension .tld. (tag library definition) and in the droplet include the path of the tag uri

For example we can write a custom tag to calculate the shipping rate with promotion and save it and then extend wherever required.

73.Difference between dsp: include and jsp:include

Ans:

Dsp imports all objects of type class also, whereas jsp imports only primitive types.

Jsp includes are dynamic whereas dsp include are for data which is smaller than 64 kb.

ATG created the DSP tag library as a mechanism for accessing all data types, including those that exist in ATG’s Nucleus framework. Other functions provided by these tags manage transactions and determine how data is rendered in a JSP. It’s best to use tags from the DSP tag library only for tasks that involve Dynamo Application Framework (DAF) resources. Dsp tag support for the passing of object parameters between pages. In particular, use dsp:include rather than jsp:include, and use dsp:param rather than jsp:param.

74.How to implement shopping cart

Ans:

ShoppingCartFormHandler

75.What is the main formhandler you use for Shopping cart

Ans:

ShoppingCartFormHandler & CartModifierFormHandler

76.What are the Advantages of DAF

Ans:

It is used to maintain huge data

It has repositories which help it with data anywhere architecture.

Dependency injection

It can write any object of type 1 call in to the db.

Dynamo messaging using patch bay and jms

“Inversion of Control” design pattern, whereby software components are discrete

entities coupled together by the Nucleus container, rather than through direct

77.How Do The Terms Atg Dynamo And Atg Framework Interact?

Ans:

The ATG framework is used by Dynamo ATG.

78.what is a pipeline

Ans:

Atg Pipeline is a variant of Servlet Pipeline, In an ATG pipeline the sequence of Programs are executed in a queue.

79.Is DAS for high volume or low volume traffic

Ans:

High volume

80.Why is Eclipse used with ATG

Ans:

Eclipse IDE

81.How will the connection be transferred from the ATG module to DB?

Ans:

/atg/dynamo/service/jdbc/JTDataSource.properties

Using JTDataSource component will maintain the Schema/DB connection

82.How The Module Dependency Happened In Atg?

Ans:

• 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/text J2ee
• ATG-EAR-Module: j2ee-apps/text J2ee
• ATG-Class-Path: bin