Interview Questions.

Question 1. What Is Bpm?

Answer :

BPM stands for Business Process Management.  There are 2 one of a kind components of BPM: BPM as control field and BPM as software program engineering.  The BPM vendors have long time attempted to make abstraction of those 2 wonderful factors.  That course result in extra confusion then something else.BPM as a management area is the obligation of each strategic govt manager.  It’s to make sure that the agency plays properly in their middle business methods.  This entails information what values the agency grants and how the ones are completed.  This approach reading, documenting and enhancing the way that human beings and structures paintings collectively.  As part of that paintings, it’s useful to paintings with fashions and diagrams.   BPMN diagrams specific the execution go with the flow of the stairs to accomplish a positive aim.   Important to note that those models are used for humans to humans communication.  They may be underspecified, which means that that they could comprise treasured high stage information without including useless information.  Such underspecified procedure fashions also are known as summary business strategies.

Question 2. What Is Jbpm?

Answer :

jBPM is a flexible Business Process Management (BPM) Suite. It makes the bridge among business analysts and developers. Traditional BPM engines have a focal point this is restrained to non-technical people simplest. JBPM has a twin recognition: it gives process control features in a way that both business customers and builders find it irresistible.

Core Java Interview Questions
Question three. What Does Jbpm Do?

Answer :

This business procedure lets in you to model your enterprise goals via describing the stairs that need to be completed to attain that intention and the order, using a waft chart. This significantly improves the visibility and agility of your business good judgment, outcomes in higher-stage and area-specific representations that may be understood by business customers and is less difficult to screen.The middle of jBPM is a light-weight, extensible workflow engine written in pure Java that lets in you to execute business processes using the ultra-modern BPMN 2.Zero specification. It can run in any Java surroundings, embedded in your software or as a carrier.

Question 4. Mention The Main Features Of Jbpm5?

Answer :

Visual person friendly editor: Users can pick among a web based editor (Oryx) or an Eclipse based one. You can select depending at the end user and in case you are going to apply the task’s BRMS (Guvnor) in which you could keep all of your commercial enterprise assets together with methods, rules and documentation in a valuable vicinity.
BPMN2 widespread assist: This lets in you to pick out a one of a kind editor to generate your commercial enterprise processes and run them in JBPM5. There’s no a hundred% assist for the standard yet, but development is being made in this matter.
Human Task functions: JBPM5 has a native perception of a Human assignment, an hobby that needs to be finished by means of an actual man or woman and has a lifecycle: it can be started, suspended, completed, and many others. It is also a wellknown spec.
Process Console: You can have interaction with the engine through this console where you may begin approaches, entire human tasks, fill bureaucracy, etc. This console is GWT primarily based.
JPA persistence approach: it enables you to select any database and staying power schema to store the methods variables and records log.
Designed for domain specific workflows: this means that you could create your personal business area particular tasks including (Receive Claim, Approve loan , Check Blood Pressure, etc) and construct a palette for end users this is very herbal to their environment. This is mixture with a visual modeler is a quite explosive aggregate, permitting a very productive as-is system know-how accumulating and to-be method design throughout an entire line of business.
Business Activity Monitoring constructed in: what’s a BPM’s well worth if you may’t reveal your techniques? JBPM5 permits you to make reports (which includes tables and charts) over the technique instance statistics and history log. This is useful for higher level customers that as C-level government who need manner records to make selections. It also permits you to use BIRT to generate your reviews, so your imagination is the restrict in terms of the quantity of statistics you could present.
Console Custom paperwork integration: By the usage of a template framework, JBPM5 lets in your users to have interaction with their techniques using  the same console to begin the technique and make moves to it within a custom shape for each pastime. For example you could have a consumer’s facts collecting activity on your method and a custom form may be built to fill that statistics into the workflow.
Powerful rules language: To make decisions in the method you can use Drools rule syntax to as an instance alternate a path consistent with a enterprise condition, which includes a credit score.
Core Java Tutorial
Question five. What Are The Advantages Of Jbpm5?

Answer :

jBPM5 affords a one-of-a-kind computational model for commercial enterprise procedure and rule. This model is primarily based on a information-oriented method, where the utility isn't procedure-oriented or rules-oriented, however the end customers can certainly pick between specific paradigms to symbolize their commercial enterprise common sense. All tools and interfaces the person is confronted with aid this concept of a unified environment all through the entire know-how life cycle.

JDBC Interview Questions
Question 6. Is The Graphical Process Designer (gpd) Only Usable In Eclipse? Is There A Way To Use It Standalone?

Answer :

The jBPM GPD is an eclipse plugin that objectives usage with the aid of a couple of roles. Both the business analyst and developer are capable of use the identical device in specific approaches. The major reason why we suppose it is critical to integrate the ones  in one unmarried environment is because in lots of groups, those  roles are performed by way of one man or woman.  Then it turns into very crucial that the device can aid each roles and progressively shift from being a diagramming device to an implementation tool.

Question 7. What Is A Rule Engine?

Answer :

A rule engine may be considered as a complicated if/then statement interpreter. The if/then statements that are interpreted are referred to as guidelines.

JDBC Tutorial JMS(Java Message Service) Interview Questions
Question eight. What Are The Advantages Of Rule Engine?

Answer :

Advantages of Rule Engines:

Greater flexibility: maintaining your regulations into a Knowledge base allow you to adapt without problems your selections while they're changing.

Easier to understand: Rules are less complicated to understand than procedural code so that they can be correctly used to bridge the gap between business analyst and developers.

Reduced complexity: When embedding plenty of decision factors for your procedural codes it is able to effortlessly turn your utility into a nightmare. On the other hand rules can deal with plenty better growing complexity due to the fact they use a regular illustration of enterprise guidelines.

Reusability: By preserving rules are stored in one area leads to a more reusability of your business guidelines. Also, traditional procedural code frequently impose needless versions of base guidelines that are consequently extra hard to reuse in different contexts.

Question 9. What Is Global In Drl File?

Answer :

Global is the key-word used in drools to outline a global variable. Global variable is the only in order to be seen to all of the rules inner a DRL record.

Globals ought to be used very cautiously in a DRL document, for the reason that modifications in a worldwide variable are not notified to the working memory. For example, you're the usage of a list variable as a global and in any rule you're including a cost in a listing and in a single particular rule, you are checking if list size() > 0, then in this example rule may not hearth. Global variable can be used for any form of object.

Java Interview Questions
Question 10. Where To Use Global Variable?

Answer :

Consider a situation, wherein inside the policies there is a requirement for database connection item. In this situation, the DB Connection item can be inserted as a international variable within the working memory and the connection item might be seen to all of the policies in that DRL document.

Java Tutorial
Question 11. What Are Needed To Set-up A Cluster With Jboss ?

Answer :

Basically beginning JBoss with the ’all’ configuration carries the whole thing wished for clustering:

It has all the libraries for clustering:

JGroups.Jar, jboss-cache.Jar
Clustered beans (cluster-service.Xml)
HA-JNDI
HTTP session replications (tc5-cluster-service.Xml)
Farming
Drools Interview Questions
Question 12. Which Component Handles Cluster Communication In Jboss?

Answer :

The JGroups framework provides offerings to enable peer-to-peer communications between nodes in a cluster. It is built on top a stack of community conversation protocols that offer delivery, discovery, reliability and failure detection, and cluster membership control offerings.

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

Answer :

It is technically possible to position a JBoss server instance into multiple clusters on the identical time, this practice is normally not advocated, as it will increase the control complexity.

Drools Tutorial
Question 14. What Is Jboss Cache In Short?

Answer :

JBossCache allows smooth distribution of datasets throughout your computing environments. It is primarily based on JGroups and permits clustering and high availability of that statistics. You can also pick to distribute the statistics with JBoss Messaging to move it wherein it is wished for computation or event-primarily based programming.

Question 15. How Do You Monitor Jboss And Detect The Bottleneck Of An Application?

Answer :

Different components of the utility are to be measured. This step is to discover in which the degradation is, whether or not it's miles outside or inner and where is the utility spending all the time. Using Joss JMX dealers and tracking the deployed additives to the software server involves within the first step.
After locating the maximum of the time spent by means of precise components or libraries or most of the resources, you could use Jprobe a specialised device for examining the unmarried object or the gadgets loaded in the reminiscence.
Java collections framework Interview Questions
Question sixteen. What Is Jta?

Answer :

Java Transaction API (JTA) specifies widespread Java interfaces among a transaction supervisor and the parties worried in a allotted transaction machine: the useful resource supervisor, the application server, and the transactional programs.

The Javaâ„¢ Transaction API (JTA) allows programs to perform distributed transactions, this is, transactions that get right of entry to and replace statistics on  or greater networked laptop sources.

The Java Transaction API consists of 3 factors: a high-level utility transaction demarcation interface, a high-level transaction manager interface intended for an utility server, and a popular Java mapping of the X/Open XA protocol meant for a transactional resource supervisor.

Java eight Tutorial
Question 17. What Is The Difference Between Hibernate And Ejb three? Do Not You Think Ejb 3 Is Just A Clone Of Hibernate?

Answer :

The perception of EJB3 as being a simple clone of Hibernate is based totally on developer familiarity with Hibernate and a similarity of naming, in addition to not unusual purpose, and that Hibernate is morphing itself into an EJB3 implementation based on the work going into the specification, not the opposite way round.
EJBs are alleged to be components, within the sense that they’re now not simply one class, but a set of lessons, descriptors and usage and control contracts. All of this so that it will allow a box (JBoss, Weblogic, etc.) to provide services to those additives, and that allows you to reuse and distribute this additives.
This offerings are, among others, transactions, concurrent get admission to manage, safety, instance pooling, etcetera.
Hibernat is “just” an ORM (Object/Relational Mapping) device. Quick and grimy, this means you could store an object tree belonging to an elegance hierarchy in a relational DB without writing a unmarried SQL question. Quite cool, IMO. But no transaction manipulate, no instance pooling, no concurrency manage, and definitely no safety.

Java eight Interview Questions
Question 18. Which Hibernate Object Wraps The Jdbc Connection?

Answer :

The Session interface wraps a JDBC Connection. This interface is a single threaded item which represents a unmarried unit of labor with utility and continual database. It’s retrieved via the SessionFactory’s openSession() approach.

JDBC Interview Questions
Question 19. Is The Session Factory Thread Safe?

Answer :

Yes: that is many threads can get entry to it cuncurrentely and request for periods. It holds cached data that has been study in one unit of work and may be reused in a future unit of work. Good practice is to create it when the application is initialized.

JAVA Persistence API (JPA) Tutorial
Question 20. How Can You Start A Jta Transaction From A Servlet Deployed On Jboss?

Answer :

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

Question 21. What If You Need To Span Your Transaction Across Multiple Servlet Invocations?

Answer :

You can’t with a Servlet. A JTA transaction must begin and finish inside a unmarried invocation (of the service() approach). You should do not forget using a Stateful SB. In a SFSB with a JTA transaction, the association among the bean instance and the transaction is retained throughout multiple customer calls.

Question 22. What Are The Differences Between Ejb three.Zero And Ejb 2.Zero?

Answer :

EJBs are now plain old Java gadgets (POJO) that expose normal enterprise interfaces (POJI), and there may be no requirement for domestic interfaces.
Use of metadata annotations, an extensible, metadata-driven, characteristic-orientated framework that is used to generate Java code or XML deployment descriptors.
Removal of the requirement for particular interfaces and deployment descriptors (deployment descriptor facts may be replaced via annotations).
Interceptor facility to invoke person techniques on the invocation of commercial enterprise strategies or at existence cycle activities.
Default values are used on every occasion possible (“configuration with the aid of exception” method).
Reduction within the necessities for usage of checked exception.
A complete new staying power model (primarily based at the JPA widespread), that supersedes EJB 2.X entity beans
Question 23. What Is The Difference Between A Local-tx-datasource And A Xa-datasource? Can You Use Transactions In Both?

Answer :

A local-tx-datasource identifies a information supply that makes use of transactions, even allotted trans moves in the local software server, but doesn’t use distributed transactions amongst more than one utility servers. An xa-datasource on the other hand identifies a information supply that uses disbursed transaction amongst multi-ple application servers.

Question 24. What Optimization Could I Use If The Ejb Container Is The Only Point Of Write Access To The Database?

Answer :

You may want to set off the “Commit Option A” that is the box caches entity bean nation among transactions. This alternative assumes that the box has unique get admission to to the persistentstore and consequently it doesn’t want to synchronize the in-memory bean kingdom from the continual shop at the start of every transaction.

JMS(Java Message Service) Interview Questions
Question 25. What Do You Know About Seam?

Answer :

Built on the standards JavaServer Faces and EJB three.0, JBoss Seam unifies component and programming fashions and grants a constant and powerful framework for fast introduction of net packages with Java EE 5.Zero. Seam simplifies net application improvement and allows new functionality that was difficult to put into effect by hand before, inclusive of stateful conversations, multi-window operation, and managing concurrent pleasant-grained AJAX requests. Seam also unifies and integrates popular open source technologies like Facelets, Hibernate, iText, and Lucene.

Question 26. Does Seam Run On Other Application Servers Besides Jboss?

Answer :

Seam runs superbly on other utility servers – much like the entirety else the Hibernate team does, this isn't always a JBoss-most effective issue.

Question 27. Which Jdk Is Needed To Run Seam?

Answer :

Seam best works on JDK 5.Zero and above. It uses annotations and different JDK five.0 capabilities.

Java Interview Questions
Question 28. 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 permits constructing of Web services and Web packages based on the SOAP 1.1 specification, Java SE 1.4 or decrease.JAX-WS 2.Zero is the successor to JAX-RPC 1.1. JAX-WS still supports SOAP 1.1 over HTTP 1.1, so interoperability will no longer be affected.

However there are masses of variations:

JAX-WS maps to Java 5.0 and relies on most of the features new in Java 5.Zero like Web Service annotations.
JAX-RPC has its very own statistics mapping version, JAX-WS’s information mapping model is JAXB. JAXB guarantees mappings for all XML schemas.
JAX-WS introduces message-orientated functionality, dynamic asynchronous functionality that are missing in JAX-RPC.
JAX-WS also upload aid, thru JAXB, for MTOM, the new attachment specification.
Question 29. Do You Know How You Could Add Support For Web Service Transactions?

Answer :

JBossTS helps Web Services transactions, consisting of prolonged transaction models designed specifically for loosely-coupled, long jogging commercial enterprise approaches. J2EE transactions can integrate seamlessly with Web Services transactions using our integrated, bi-directional transaction bridge. Interoperability with many different providers is provided out-of-the-field and JBoss is an active participant in these requirements.

Question 30. What Version Of Jboss As Do I Need To Run Seam?

Answer :

For Seam 1.3: Seam changed into evolved against JBoss 4.2. Seam can nonetheless be run against JBoss 4.Zero. The seam documentation contains commands for configuring JBoss 4.0.

For Seam 1.2: Since Seam calls for the trendy edition of EJB3, you need to put in JBoss AS from the state-of-the-art JEMS installer. Make certain which you select the “ejb3” or “ejb3+clustering” profile to encompass EJB3 guide. Also, the jboss-seam.Jar library file from the Seam distribution should be included in each Seam software you set up. Refer to examples in Seam distribution (inside the examples directory) to peer how to build and package Seam packages.

Question 31. Can I Run Seam In A J2ee Environment?

Answer :

Yes, as of Seam 1.1, you could use Seam in any J2EE software server, with one caveat: you'll now not be capable of use EJB 3.Zero session beans. However, you could use both Hibernate or JPA for staying power, and you could use Seam JavaBean components in preference to session beans.

Question 32. Can I Run Seam With Jdk 1.4 And Earlier?

Answer :

No, Seam handiest works on JDK five.Zero and above. It makes use of annotations and different JDK 5.0 functions.

Question 33. Where Can I Find Seam Examples And Documentation?

Answer :

The source code and construct script of all Seam instance packages are protected inside the examples listing of the Seam distribution.

Drools Interview Questions
Question 34. Is It True That Seam Only Works With Jsf?

Answer :

Seam handiest helps JSF as a view framework at this time. We plan to support other net frameworks in the destiny. We like JSF as it is a component-based UI framework, which suits simply properly with Seam’s component-based totally approach to business items and endurance items. Seam made a prime improvement to JSF with the aid of putting off nearly all XML configuration for backing beans — you may now outline again beans from POJOs or EJB3 components using simple annotations. We propose you operate Facelets, as opposed to JSP, with JSF. Facelets provide a powerful templating framework, better software performance, and permits us to put in writing a good deal less difficult JSF pages.

Question 35. Can I Use Ajax With Seam?

Answer :

Yes, Seam gives fantastic support for AJAX. First, Seam supports the ICEfaces and Ajax4JSF Ajax factor libraries for JSF. If you choose a extra “old-fashioned” method, Seam affords a whole JavaScript remoting framework which lets you call Seam components and join JMS topics without delay from the customer. Please discuss with the Seam remoting instance utility on a way to use AJAX remoting to implement a chat room.

Question 36. Can I Unit Test Seam Applications Without Starting The Application Server?

Answer :

Yes, Seam gives its very own integration take a look at framework based on TestNG. You can easily mock all Seam offerings the use of those facilities without ever loading an application server or a database. Refer to the take a look at instance ANT goal within the Seam reserving instance application for greater info.

Java collections framework Interview Questions
Question 37. What Is Drools?

Answer :

Drools is a Business Rules Management System (BRMS) solution. It offers a middle Business Rules Engine (BRE), a web authoring and regulations control software (Drools Workbench) and an Eclipse IDE plugin for core improvement.

Question 38. Is The Graphical Process Designer (god) Only Usable In Eclipse? Is There A Way To Use It Standalone?

Answer :

The jBPM GPD is an eclipse plugin that goals usage by using multiple roles.  Both the enterprise analyst and developer are capable of use the equal tool in special approaches.  The foremost reason why we think it's miles important to combine the ones  in a single unmarried environment is because in many groups, these  roles are done with the aid of one individual.  Then it turns into very important that the tool can assist each roles and step by step shift from being a diagramming device to an implementation tool.

Question 39. Explain The Difference Between Stringbuilder And Stringbuffer Class?

Answer :

StringBuilder is unsynchronized while StringBuffer is synchronized. So while the application needs to be run best in a single thread then it's miles better to apply StringBuilder. StringBuilder is more green than StringBuffer.