Interview Questions.

Question 1. What Is Jboss?

Answer :

JBoss is a popular open supply software server based on JEE generation. Being JEE primarily based, the JBoss helps cross-platform java applications. It became embedded with Apache Tomcat net server. It runs beneath any JVM of one.Three or later variations. JBoss helps JNDI, Servlet/JSP (Tomcat or Jetty), EJB, JTS/JTA, JCA, JMS, Clustering (JavaGroups), Web Services (Axis), and IIOP integration (JacORB).

Question 2. What Is Jboss Cache In Short?

Answer :

JBoss cache is a product. Frequently accessed Java items are cached by means of utilzing JBoss cache to improve the performance of e-enterprise applications. JBoss decreases the network site visitors and will increase the scalability of packages by means of casting off unnecessary database access. Fully transactional functions and particularly configurable set of alternatives that are to cope with concurrent statistics get right of entry to, are provided with the aid of JBoss cache in an efficient manner feasible for the packages.

J2EE Interview Questions
Question three. What Is Jboss Jbpm?

Answer :

JBoss JBPM is a workflow and BPM engine. Enabling the advent of enterprise tactics that coordinates between people, programs and offerings is the capability of BPM engine. The combination of workflow packages improvement with process layout is a feature of JBoss jBPM. The commercial enterprise technique is graphically represented to facilitate a strong hyperlink among the commercial enterprise analyst and technical developer. This function is furnished by using the JBoss jBPM system dressmaker.

Question 4. How Do You Monitor Jboss And Detect The Bottleneck Of An Application?

Answer :

Different additives of the application are to be measured. This step is to discover in which the degradation is, whether it's miles outside or internal and in which is the application spending all the time. Using Jboss JMX dealers and monitoring the deployed components to the software server entails inside the first step.

After finding the most of the time spent by way of unique additives or libraries or most of the sources, you may use Jprobe a specialized device for inspecting the single object or the gadgets loaded within the memory.

J2EE Tutorial
Question 5. What Is Jta?

Answer :

Java Transaction API (JTA) specifies trendy Java interfaces among a transaction supervisor and the events concerned in a allotted transaction gadget: the useful resource supervisor, the software server, and the transactional programs.

The Javaâ„¢ Transaction API (JTA) permits applications to perform disbursed transactions, this is, transactions that get right of entry to and replace statistics on  or greater networked pc sources.

The Java Transaction API includes 3 factors: a high-level application transaction demarcation interface, a excessive-stage transaction supervisor interface intended for an application server, and a trendy Java mapping of the X/Open XA protocol intended for a transactional useful resource supervisor.

EJB(Enterprise JavaBeans) Interview Questions
Question 6. What Is The Difference Between Hibernate And Ejb three? Do Not You Think Ejb three Is Just A Clone Of Hibernate?

Answer :

The belief of EJB3 as being a easy a dead ringer for Hibernate is based on developer familiarity with Hibernate and a similarity of naming, in addition to common reason, and that Hibernate is morphing itself into an EJB3 implementation based at the paintings going into the specification, not the opposite way around.

EJBs are speculated to be components, in the feel that they’re no longer simply one class, but a set of training, descriptors and usage and control contracts. All of this that allows you to permit a field (JBoss, Weblogic, etc.) to provide offerings to those additives, and to be able to reuse and distribute this components. This offerings are, among others, transactions, concurrent get admission to manipulate, protection, example pooling, and so on.

Hibernate is “simply” an ORM (Object/Relational Mapping) tool. Quick and grimy, this indicates you may shop an item tree belonging to an elegance hierarchy in a relational DB without writing a single SQL query. Quite cool, IMO. But no transaction manage, no example pooling, no concurrency control, and honestly no safety.

Question 7. Which Hibernate Object Wraps The Jdbc Connection?

Answer :

The Session interface wraps a JDBC Connection. This interface is a single threaded object which represents a single unit of work with utility and continual database. It’s retrieved by the SessionFactory’s openSession() technique

EJB(Enterprise JavaBeans) Tutorial IBM Websphere Application Server Interview Questions
Question eight. Is The Session Factory Thread Safe?

Answer :

Yes, that is many threads can get right of entry to it concurrently and request for classes. It holds cached records that has been study in a single unit of labor and may be reused in a destiny unit of work. Good exercise is to create it while the software is initialized.

Question 9. How Can You Start A Jta Transaction From A Servlet Deployed On Jboss?

Answer :

JBoss registers in the JNDI tree a JTA UserTransaction Object which may be consumer to control a allotted transaction.

Java EE Connector Architecture (JCA) Interview Questions
Question 10. What If You Need To Span Your Transaction Across Multiple Servlet Invocations?

Answer :

You can’t with a Servlet. A JTA transaction have to begin and end within a unmarried invocation (of the service() technique). You must consider the usage of a Stateful SB. In a SFSB with a JTA transaction, the affiliation between the bean instance and the transaction is retained across a couple of patron calls.

JBPM Tutorial
Question 11. What Are The Differences Between Ejb three.0 And Ejb 2.0?

Answer :

EJBs at the moment are simple vintage Java gadgets (POJO) that disclose normal enterprise interfaces (POJI), and there's no requirement for home interfaces.

Use of metadata annotations, an extensible, metadata-pushed, characteristic-oriented framework that is used to generate Java code or XML deployment descriptors.
Removal of the requirement for specific interfaces and deployment descriptors (deployment descriptor information can be changed via annotations).
Interceptor facility to invoke consumer methods on the invocation of enterprise techniques or at life cycle activities.
Default values are used each time possible.
Reduction within the necessities for usage of checked exception.
A whole new patience model (based on the JPA fashionable), that supersedes EJB 2.X entity beans
Soap UI Interview Questions
Question 12. What Is The Difference Between A Local-tx-datasource And A Xa-datasource? Can You Use Transactions In Both?

Answer :

A neighborhood-tx-datasource identifies a information source that makes use of transactions, even disbursed trans moves in the neighborhood software server, however doesnt use dispensed transactions among multiple software servers. An xa-datasource then again identifies a records supply that uses allotted transaction among multiple utility servers.

J2EE Interview Questions
Question 13. What Do You Need To Set-up A Cluster With Jboss?

Answer :

Basically beginning JBoss with the configuration carries the whole thing wanted for clustering:

It has all the libraries for clustering:

JGroups.Jar, jboss-cache.Jar.
Clustered beans (cluster-service.Xml).
HA-JNDI.
HTTP consultation replications (tc5-cluster-provider.Xml).
Farming.
HA-JMS.
Question 14. What Optimization Could I Use If The Ejb Container Is The Only Point Of Write Access To The Database?

Answer :

You ought to activate the “Commit Option A” that is the field caches entity bean nation among transactions. This choice assumes that the box has specific get admission to to the continual save and consequently it doesnt want to synchronize the in-reminiscence bean kingdom from the persistent save at the start of each transaction.

Question 15. Which Component Handles Cluster Communication In Jboss?

Answer :

The JGroups framework gives offerings to enable peer-to-peer communications between nodes in a cluster. It is built on top a stack of community conversation protocols that provide delivery, discovery, reliability and failure detection, and cluster club management services.

JBPM Interview Questions
Question sixteen. Is It Possible To Put A Jboss Server Instance Into Multiple Cluster At The Same Time?

Answer :

It is technically feasible to position a JBoss server example into a couple of clusters on the same time, this practice is commonly no longer recommended, as it increases the control complexity.

Question 17. What Do You Know About Seam?

Answer :

Built at the standards Java Server Faces and EJB 3.0, JBoss Seam unifies factor and programming models and can provide a constant and powerful framework for fast advent of web programs with Java EE 5.0. Seam simplifies net utility improvement and permits new functionality that become hard to put in force by using hand earlier than, such as stateful conversations, multi-window operation, and coping with concurrent first-rate-grained AJAX requests. Seam also unifies and integrates popular open source technology like Facelets, Hibernate, iText, and Lucene.

Advanced Linux Interview Questions
Question 18. Does Seam Run On Other Application Servers Besides Jboss?

Answer :

Seam runs beautifully on different software servers – similar to the whole thing else the Hibernate crew does, this isn't a JBoss-only element.

EJB(Enterprise JavaBeans) Interview Questions
Question 19. Which Jdk Is Needed To Run Seam?

Answer :

Seam simplest works on JDK 5.Zero and above. It makes use of annotations and different JDK 5.0 capabilities.

Question 20. How Would You Convince My It Department To Adopt Soa?

Answer :

In my opinion one in all the biggest obstacle within the motion in the direction of SOA adoption is the agency very own IT branch.Too many people in the IT enterprise conceive SOA as a era concept simplest, and as such consider SOA as just a set of technologies and infrastructure for exposing, securing, strolling, and coping with Services.

Put it this way, SOA is nothing greater than Web Services and standardized middleware. The essential flaw in wondering is puzzling the technology that sits underneath the Services stage of abstraction and the mechanism by using which Services are accessed with the architectural method that ambitions to decouple the implementation from the intake and awareness on sustainable architecture that lets in for continuous trade.

Successful SOA adoption calls for a cultural shift in the way IT is achieved. The Service-orientated movement to agility and unfastened coupling needs a shift from traditional, waterfall styles of development (layout-build-check-set up-manipulate) to iterative tactics to non-stop Service modeling

WebLogic Administration Interview Questions
Question 21. What Do You Think About Bpel And Bpm ? How Do They Compare?

Answer :

BPEL and BPM are pretty different things so they cannot even be compared. The troubles boils right down to the reality that those years maybe BPEL has been marketed for something which isn’t: that could be a Business Process Management framework.
BPEL is made up for carrier orchestration, this is publishing new offerings as a function of different services.
Even as BPM si wished for handling human venture management functionalities and subprocess management.
Question 22. What Is The Difference Between Jax–ws And Jax-rpc?

Answer :

Java API for XML-Based RPC (JAX-RPC) is a Legacy Web Services Java API, it makes use of SOAP and HTTP to do RPCs over the community and allows constructing of Web offerings and Web packages based on the SOAP 1.1 specification, Java SE 1.4 or lower.JAX-WS 2.0 is the successor to JAX-RPC 1.1. JAX-WS nevertheless helps SOAP 1.1 over HTTP 1.1, so interoperability will now not be affected. However there are plenty of variations:

JAX-WS maps to Java 5.Zero and is based on a number of the features new in Java 5.Zero like Web Service annotations.
JAX-RPC has its personal statistics mapping version, JAX-WS’s information mapping version is JAXB. JAXB promises mappings for all XML schemas.
JAX-WS introduces message-orientated functionality, dynamic asynchronous capability which can be missing in JAX-RPC.
JAX-WS also upload help, via JAXB, for MTOM, the new attachment specification.
Question 23. Do You Know How You Could Add Support For Web Service Transactions?

Answer :

JBossTS supports Web Services transactions, which includes prolonged transaction fashions designed in particular for loosely-coupled, lengthy jogging commercial enterprise processes. J2EE transactions can combine seamlessly with Web Services transactions the use of our incorporated, bi-directional transaction bridge. Interoperability with many other companies is supplied out-of-the-field and JBoss is an energetic participant in these standards.

Apache Tomcat Interview Questions
Question 24. What Version Of Jboss As Do I Need To Run Seam?

Answer :

For Seam 1.Three: Seam turned into developed towards JBoss four.2. Seam can nonetheless be run against JBoss four.0. The seam documentation incorporates commands for configuring JBoss 4.Zero.

For Seam 1.2: Since Seam calls for the present day edition of EJB3, you want to put in JBoss AS from the brand new JEMS installer. Make certain which you pick out the “ejb3” or “ejb3+clustering” profile to include EJB3 aid. Also, the jboss-seam.Jar library record from the Seam distribution need to be blanketed in every Seam utility you install. 

IBM Websphere Application Server Interview Questions
Question 25. Can I Run Seam Outside Of Jboss As?

Answer :

Yes, you could run Seam packages in plain Tomcat 5.5+ or within the Sun GlassFish software server. To run Seam utility in Tomcat, you need some of additional library files and a few configuration files to bootstrap the JBoss EJB3 internal Tomcat.

Question 26. Can I Run Seam In A J2ee Environment?

Answer :

Yes, as of Seam 1.1, you may use Seam in any J2EE software server, with one caveat: you'll not be capable of use EJB three.0 session beans. However, you could use either Hibernate or JPA for persistence, and you can use Seam JavaBean components in preference to session beans.

GlassFish Interview Questions
Question 27. Can I Run Seam With Jdk 1.4 And Earlier?

Answer :

No, Seam only works on JDK five.0 and above. It uses annotations and different JDK five.0 features.

Java EE Connector Architecture (JCA) Interview Questions
Question 28. Where Can I Find Seam Examples And Documentation?

Answer :

The supply code and build script of all Seam example programs are blanketed in the examples directory of the Seam distribution.

Question 29. Is It True That Seam Only Works With Jsf?

Answer :

Seam simplest helps JSF as a view framework at this time. We plan to help other internet frameworks in the future. We like JSF as it is part-based totally UI framework, which fits truely well with Seam’s issue-primarily based technique to enterprise gadgets and patience gadgets. Seam made a major development to JSF by using removing almost all XML configuration for backing beans — you can now define again beans from POJOs or EJB3 additives the usage of simple annotations.

We advise you operate Facelets, rather than JSP, with JSF. Facelets offer a powerful templating framework, higher appplication overall performance, and allows us to write down a lot easier JSF pages. Please see the Seam reserving instance utility for an instance on a way to use Facelets.

Middleware Interview Questions
Question 30. Can I Use Ajax With Seam?

Answer :

Yes, Seam presents tremendous help for AJAX. First, Seam supports the ICEfaces and Ajax4JSF Ajax element libraries for JSF. If you pick a extra “old fashioned” method, Seam offers a complete JavaScript remoting framework which helps you to call Seam additives and join JMS subjects directly from the purchaser. 

Question 31. Can I Unit Test Seam Applications Without Starting The Application Server?

Answer :

Yes, Seam offers its personal integration test framework based totally on TestNG. You can easily mock all Seam offerings the use of the ones facilities with out ever loading an utility server or a database. 

Question 32. How Do You Perform A Hot Deployment?

Answer :

JBoss has a built-in warm deployer that could:

Detect new programs in the installation folder and trigger an utility deployment
Detect an software which was eliminated from the install folder and trigger an utility undeployment
Detect that the deployment descriptor of an software (for example, the web.Xml of .Struggle or application.Xml of .Ear) has changed and trigger an utility redeployment
Question 33. How Do You Enable/disable A Hot Deployment?

Answer :

To allow, put file hdscanner-jboss-beans.Xml in  JBOSS_HOME/server/<profilename>/installation
To disable hot deployment, take away the hdscanner-jboss-beans. Xml from the set up folder or rename it to hdscanner-jbossbeans. Xml.Bak (.Bak documents are neglected).
Soap UI Interview Questions
Question 34. What Is Jboss Eap?

Answer :

JBoss Enterprise Application Platform is an open supply implementation of the Java EE suite of offerings

Question 35. How Do You Deploy An Application To Jboss?

Answer :

 Choose the server profile to which you need to install the software

Copy your application (as an instance: .Struggle or .Ear or a .Jar record) to JBOSS_HOME/server/<profilename>/installation folder.
Start the server: (./run.Sh)
JBoss will deploy your application whilst it boots up.
Question 36. What Does Mgmt-user.Properties Contain?

Answer :

All admin console customers and password (encrypted) are saved in mgmt.-user.Homes record.

JBPM Interview Questions
Question 37. What Are The Important Types Available For Marker File Deployment?

Answer :

.Dodeploy – coach to install
.Deployed – suggest the file is deployed
.Pending – deployment is still pending
.Undeployed – affirmation that software is undeployed
.Failed – deployment is failed for a few purpose
.Skipdeploy – train JBoss to disregard the files for auto-deployment
Question 38. What Marker File Type Is Required To Instruct Jboss To Deploy?

Answer :

.Dodeploy file suffix is wanted for JBoss to installation or redeploy an utility.
For ex: myfirstapplication.Warfare.Dpdeploy

Question 39. How Can You Deploy An Application?

Answer :

There are 3 feasible methods to install an utility in JBoss software server.

Admin Console – you can deploy the necessary application documents via the management console.
Auto-install – leverage document device deployment scanner to car installation documents from deployments folder.
Automation – use automation device/ant/scripting to set up an software.
Question forty. What Are The File Types You Can Deploy In Jboss?

Answer :

You can installation nearly any sort of Java/J2EE software, and it helps the subsequent record layout.

WAR: Web utility archive
SAR: Service archive
JAR: Java Archive
EAR: Enterprise application archive
Advanced Linux Interview Questions
Question 41. What Module Needed To Integrate Apache With Jboss?

Answer :

There are  modules you may use to connect JBoss with Apache.

Mod_proxy.
Mod_jk.
Question forty two. What Is Difference Between <validate-on-match> And <background-validation>?

Answer :

<validate-on-match> validate the database connection on every occasion, and if a connection is not legitimate, it will write a caution inside the logs.
Having “validate-on-in shape” configured may additionally have a touch excessive load at the database as it is able to create plenty of requests.
<background-validation> validate the connection periodically primarily based on what frequency is configured for “history-validation-millis”. The default configuration is ready to zero manner disabled.
Having “ heritage-validation” set to authentic will create fewer database connections and it’s facet-effects would be now not detecting at once if lifeless connections.
WebLogic Administration Interview Questions
Question 43. Can You Create A Cluster In Standalone Mode?

Answer :

Yes, clustering is feasible in standalone mode. However, an utility have to be deployed on every server/JVM in standalone mode.

Question forty four. What Is The Difference Between Standalone And Domain Mode?

Answer :

Standalone mode is single JVM process wherein every JBoss server has its configuration. If you just want one JVM or improvement environment, then standalone could be best.
Domain mode may also have a couple of servers wherein all configuration is managed centralized and often used in production environment.
Question forty five. How To Increase Java Heap Memory In Jboss 7?

Answer :

Heap Memory may be expanded in a respective conf file. To growth reminiscence for standalone;

Go to bin folder
Edit the standalone.Conf report and look for “JAVA_OPTS=” argument line
The default configuration can have minimum 64 MB and most 512 MB. You can increase to the favored value.
Xms – specify the minimal heap size.
Xmx – specify the most heap size.
In a similar manner, you can alter the memory for a site in area.Conf file

Question forty six. How To Start Jboss In Standalone Mode?

Answer :

Go to bin folder where JBoss is set up and start with the following command.

./standalone.Sh

Question forty seven. What Must Be Done To Access Admin Console?

Answer :

The person have to be created below “ManagementRealm” to have console operational. To create the consumer, you may go to bin folder and execute add-user.Sh script.

Question forty eight. What’s The Default Port To Access Administration Console In Jboss 7?

Answer :

9990 is the default port. If it’s installed on server1 then you definately want to get admission to like:
http://server1:9990/admin-console

Question forty nine. How To Install Jboss On Linux Server?

Answer :

JBoss installation may be very sincere. You need to down load the favored version from JBoss respectable download page in zip or gz layout.

Once downloaded, simply extract the report to the area you need to install. If you downloaded zip format, then you can use unzip command to extract it.

Unzip jboss-as-7.1.1.Final.Zip

Question 50. Which Component Is Responsible For Handling Clustering?

Answer :

JBoss clustering is on top of JGroups toolkit which facilitates to create, delete, membership detection, notification, etc. In the cluster.

Question 51. What Are The Logging Levels Available?

Answer :

There is 5 feasible degree:

FATAL
ERROR
WARN
INFO
DEBUG
Question fifty two. What Is The Directory Structure In Jboss?

Answer :

The following directories are available after JBoss is installed.

Modules
bundles
domain
standalone
appclient
bin
medical doctors
welcome-content material
Question fifty three. What Is A .War, .Ear Or A .Jar File??

Answer :

WAR – internet utility archive is a jar file used to distribute a set of JavaServer Pages, Java Servlets, Java classes, xml files, tag libraries, static internet pages (html & others) and others assets that constitute an internet software.
JAR – Java Archive, is an archive file layout commonly used to combination many Java magnificence files and related metadata and assets into one document to distribute software software program, libs on the Java platform.
EAR – Enterprise Archive is used to package one or more moduels right into a unmarried archive so the deployment of the various modules into app server happen simultaneiously and coherently.
Question 54. What’s The Difference Between A Tar File And A War File?

Answer :

TAR – derived from tape archive is a report format to archive bitstreams and call of a program to handle such documents.  It is typically used to accumulate many documents into one big report for distributing or archiving while maintaining the filesystem information.
WAR – net utility archive is a jar report used to distribute a group of JavaServer Pages, Java Servlets, Java instructions, xml files, tag libraries, static internet pages (html & others) and others assets that constitute a web application.
Question 55. How Do You Look Inside A Jar File?

Answer :

 jar –tf <filename.Jar>