Interview Questions.

Q1. What Is Work Managers?

The Work Manager tab contains the list of configured Work Managers. New Work Managers may be added, eliminated, and their thread swimming pools configured here. Each Work Manager may have one short-walking thread pool and an optionally available long-going for walks thread pool.

Q2. What Is Contracts?

The Java EE Connector Architecture defines a standard for connecting a compliant utility server to an EIS. It defines a popular set of machine-level contracts between the Java EE application server and a aid adapter. The system contracts described by way of Version 1.Zero of the Java EE Connector Architecture are defined by using the specification as follows:

Connection management : Connection management enables an application server to pool connections to the underlying EIS and permits application additives to attach. This results in a scalable application surroundings that may assist a huge number of customers.

Traction management : Traction management permits an application server to use a traction supervisor to control tractions across multiple resource managers. This agreement additionally supports tractions which can be managed inner to an EIS resource supervisor with out the necessity of regarding an outside traction manager.

Security management: Security control reduces safety threats to the EIS and protects valuable statistics resources controlled through the EIS. JCA Version 1.5 provides machine contracts to the specification as follows:

Life cycle management : Life cycle control permits an utility server to control the life cycle of a aid adapter from initiation thru enhancements to obsolescence. This agreement presents a mechanism for the software server to bootstrap a resource adapter example all through its deployment or application server startup, and to inform the useful resource adapter example during its dedeployment or throughout an orderly shutdown.

Work management : Work control enables a aid adapter to do work (reveal community endpoints, invoke utility components, and so forth) by means of submitting work instances to an software server for execution. The software server dispatches threads to execute submitted work instances. This allows a aid adapter to avoid creating or dealing with threads immediately, and lets in an application server to efficiently pool threads and have more manage over its runtime surroundings. The useful resource adapter can manage the traction context with which work instances are executed.

Traction influx management : Traction influx control allows a useful resource adapter to propagate an imported traction to an application server. This agreement also allows a useful resource adapter to trmit traction of completion and crash healing calls initiated via an EIS, and guarantees that the Atomicity, Consistency, Isolation and Durability (ACID) homes of the imported traction are preserved.

Message influx control : Message inflow management allows a resource adapter to asynchronously deliver messages to message endpoints dwelling within the software server, independent of the specific messaging fashion, messaging semantics and messaging infrastructure used to supply messages. This contract additionally serves as the same old message issuer pluggability contract that allows a huge variety of message carriers (Java Message Service (JMS), Java API for XML Messaging (JAXM), and so on) to be plugged into any Java EE compatible software server with a aid adapter.

Q3. What Is Cached Connection Manager?

Used for debugging connections and supporting lazy enlistment of a connection in a traction, tracking whether or not they may be used and released nicely via the utility.

Q4. What Is Jca And A General Integration Strategy?

These days, many systems ought to combine with other systems. We describe numerous integration types and where JCA fits into them. Integration falls into two important buckets:

Inbound integration: outside structures initiate information requests to your machine.

Outbound integration: your gadget initiates information requests to different structures.

All of the subsequent integration kinds may be implemented in both an inbound and an outbound way.

Q5. What Is Message Broker?

Messaging brokers, another characteristic not unusual to many EAI products, normally permit each point-to-factor and post/subscribe messaging. EAI products often rent messaging because the connectivity layer to tie collectively disparate systems.

Currently JCA does now not address connectivity to an EIS in a message-oriented way. It is possible, however, to implement some of a message broker's function set in an EAI product through the use of JMS (Java Messaging Service), that is part of J2EE.

Q6. What Is Connection Management Contracts?

The connection control contract describes the know-how a J2EE container has with the adapter regarding establishing, pooling, and tearing down connections. The connection management contract additionally allows listeners created on a connection to respond to activities (as an example if the relationship becomes misplaced or reviews an mistakes). Also word that the underlying protocol an adapter uses to connect with an EIS is outdoor the scope of the JCA specification.

All JCA aid adapters ought to deliver two implementations with the adapter. First, a ConnectionFactor provides a automobile for creating connections. Second, the Connection elegance represents this unique useful resource adapter's underlying connection.

Q7. How Jca And J2ee Compare To Eai Products?

With that heritage in thoughts, allow's take into account how the cutting-edge version of the JCA specification -- as well as J2EE in widespread -- measure up to some of the capabilities found in EAI vendors' products.

Many EAI providers, Vitria and Tibco for example, have either introduced JCA support, or are in the technique of releasing merchandise that incorporate JCA-primarily based adapters. Because the JCA 1.Zero specification become finalized in July 2001, don't assume JCA in its preliminary release to match characteristic for function to an EAI supplier's product, neither is that the goal. (Many features of the J2EE platform additionally examine to features in many EAI merchandise.)

Q8. What Is Workflow?

Workflow is the control of business procedures. Think of workflow as a coordinator. In and of itself, workflow lacks the functionality to do anything, but rather relies on commercial enterprise gadgets, messages, and different external entities to carry out capability (as an example growing a user item in a database). Workflow coordinates using enterprise objects, messages, and so forth to carry out commercial enterprise processes.

JCA does not deal with workflow. However, search for some thing in the J2EE area to deal with workflow, as it serves as an important element whilst growing a complicated gadget.

Having discussed how JCA (and J2EE) compare with EAI gear, it is now essential to take a look at how JCA fits into an usual integration strategy.

Q9. What Is Cci?

To retrieve and replace records, you rent JCA's CCI layer, a manner such as the use of JDBC to call stored processes. A JCA aid adapter isn't always required to aid the CCI layer (the resource adapter creators can choose their very own API set), and, despite the fact that the useful resource adapter does assist CCI, it is able to also support an API particular for that unique adapter.

The CCI APIs can be divided into 4 sections: First, the APIs related to setting up a connection to an EIS, also referred to as the Connection Interfaces. The second region of the CCI APIs cowl command execution on an EIS, referred to as theInteraction Interfaces. Third is the Record/ResultSet Interfaces,which encapsulate the query outcomes to an EIS. The fourth vicinity, known as the Metadata Interfaces, allows EIS's metadata (the sort of records) to be queried.

After this brief assessment of the CCI APIs, it's miles useful to have a look at an instance that indicates the question of an worker rely from an EIS:

intcount; 

attempt

 

ConnectionSpec spec =newCciConnectionSpec(consumer, password);

Connection con = cf.GetConnection(spec);

Interaction ix = con.CreateInteraction(); 

CciInteractionSpec iSpec = new CciInteractionSpec();

iSpec.SetSchema(user); iSpec.SetFunctionName("EMPLOYEECOUNT");

RecordFactory rf =cf.GetRecordFactory(); 

IndexedRecord iRec =rf.CreateIndexedRecord("InputRecord"); 

Record rec =ix.Execute(iSpec, iRec); 

Iterator iter =((IndexedRecord)rec).Iterator();

at the same time as(iter.HasNext())

 

Object obj = iter.Next();

if(obj instanceof Integer)

 

matter = ((Integer)obj).IntValue();

 

 

con.Near(); 

 

catch(Exception e) 

 

e.PrintStackTrace(); 

System.Out.Println("Employee depend is: " + matter);...

Q10. What Is User Interface Integration?

User interface (UI) integration represents the maximum coarse-grain kind of integration. UI-stage integration implies that the facts exceeded among systems will exist inside the form of a UI illustration. An outbound integration on the UI level includes inquiring for the UI (most possibly a Webpage) from a far off machine, then possibly manipulating it before showing it as if it had been a part of your machine's UI. An inbound integration on the UI degree includes allowing an outdoor gadget to request UI pages to your device for inclusion on a far off system.

Prefer UI integration over other alternatives while it's far unimportant to differentiate the data type being retrieved. UI integration regularly calls for the least attempt to put in force.

Q11. What Is Object/rpc Integration?

Object/RPC (far off technique call) integration implies integrating structures using dispensed items (that is, using EJB calls to combine). With item-level integration, records passes among structures as parameters to technique calls. In an outbound object-degree integration, your device invokes items on remote structures, even as in an inbound item-level integration, a faraway gadget calls items in your device to retrieve information.

One of an object-degree integration's primary advantages is that you can call special APIs with complete kind protection and easily propagate the error codes and exceptions among structures.

Q12. What Is Common Config?

The Common Config tab includes settings for the cached connection manager, archive validation and bean validation ((JSR-303). Each of those is contained of their personal tab as well. These settings may be changed via establishing the ideal tab, clicking the edit button, making the required changes, after which clicking at the save button.

Q13. What Is Message Integration?

Message-degree integration, all the rage with the appearance of Web offerings, implies that the statistics surpassed among structures may be within the form of a message (a defined, information-pushed textual content format). An outbound message integration entails asking for records from a far flung gadget in a message form (most in all likelihood a SOAP (Simple Object Access Protocol) message). With an inbound integration, your machine receives a request for facts through a message and responds with a message.

Message-orientated integration lends itself to free coupling among structures due to the fact the systems stay blind to the object kinds that exist at the faraway system. That form of free coupling works well with applications that wish to talk over the Internet.

Q14. Configure The Java Connector Architecture (jca) Subsystem?

The JCA subsystem inside the JBoss Enterprise Application Platform 6 configuration document controls the overall settings for the JCA box and aid adapter deployments.

Key factors of the JCA subsystem

Archive validation.

This placing whether archive validation can be carried out on the deployment units.

The following table describes the attributes you could set for archive validation.

Q15. What Is Eis Integration?

JCA adapters may be constructed to combine with diverse Enterprise Information System including Siebel Systems, SAP AG, Great Plains Systems, Oracle Applications, and many others. Siebel presents API to combine with diverse systems like Java, C++, .Net, Visual Basic, and so forth. For Java it gives an interface called 'Java Data Bean' (JDB). The Siebel adaptor affords facts get admission to via the JDB API. Great Plains Systems offers an interface referred to as eConnect to combine with other structures. SAP presents an interface for Java called SAP Java Connector (SAP JCo).

Q16. What Is Resource Adapter?

In order to apply JCA in a J2EE box, you first should have a JCA aid adapter, which resembles a JDBC driver. A JCA adapter is particular to an EIS (for instance SAP or PeopleSoft) and is contained in a Resource Adapter Archive (RAR) record composed of the jar files and native libraries vital to installation the aid adapter on a J2EE box. A JCA adapter interacts with a J2EE server with device contracts. They enable the J2EE server to propagate the context wherein a JCA adapter is being referred to as.

You'll find three forms of device contracts:

Connection management

Traction management

Security

Q17. What Is Data Integration?

Lastly, records-stage integration means that the information passed among systems could be in a records/file-oriented manner. In an outbound records-stage integration, your gadget requests facts in a file-oriented fashion from different structures. With an inbound statistics-stage integration, a far off device requests records from your gadget in a report-orientated way.

The advantage of a information level integration: it lends itself to records mapping from one machine onto the commercial enterprise items in another machine. JCA falls into the records-stage integration class and consequently has the strengths and weaknesses of this integration type.

Now that we have protected where JCA fits into the general integration puzzle, we are geared up to discuss the JCA's structure.

Q18. What Is Data Mapping?

With the next EAI function -- information mapping -- facts acquired in one format (as an example inside the EIS's local layout) through the resource adapter have to be trformed into the format required for the business item. Mapping statistics from one device to every other regularly proves the maximum time ingesting element of device integration due to the fact you should map every business item in each systems. In response, maximum EAI companies provide visual tools to permit a developer to installation such mapping.

Q19. What Is Bean Validation?

This setting determines whether or not bean validation (JSR-303) may be done at the deployment gadgets.

Q20. What Is Security Contract?

The security settlement permits the application server to hook up with an EIS machine the use of protection properties. The software server authenticates with the EIS machine through using safety properties composed of a principle (a person identification) and credentials (a password, a certificates, and so forth). An software server can hire two methods to authenticate to an EIS system (through a aid adapter). With the primary approach, field-managed sign-on, the security credentials configure while the useful resource adapter is deployed on the software server. You can select from several methods to configure security residences while the use of box-managed sign-on. First, with Configured Identity, all useful resource adapter connections use the equal identity when connecting to the EIS machine.

Second, with Principal Mapping, the primary used when connecting to the EIS system is primarily based on a combination of the modern fundamental within the utility server and the mapping (which maps how the major in the utility server will map to a essential inside the EIS machine). The third is Caller Impersonation, wherein the primary used within the EIS system exactly fits the important inside the utility server. The fourth is Credentials Mapping, that is similar to Caller Impersonation, besides the form of credentials should be mapped from software server credentials to EIS credentials.

While it's simplest to configure the security residences at deployment time, this kind of method proves barely less bendy because the safety houses can't exchange at runtime. As an alternative, you could configure security houses via factor-managed sign-on, which permits you to skip safety houses every time a connection is acquired from the useful resource adapter.

Q21. What Are Thread Pool Attributes?

Permit-core-timeout:Boolean setting that determines whether core threads may also day trip. The default fee is fake.

Middle-threads:The middle thread pool size. This must be smaller than the maximum thread pool length.

Queue-length:The most queue length.

Max-thread:The most thread pool length.

Keepalive-time:Specifies the amount of time that pool threads need to be stored after doing paintings.

Thread-manufacturing facility:Reference to the thread manufacturing facility .

Q22. What Is Jca's Structure?

JCA evaluate: Its fundamental components encompass the resource adapter, system contracts, and the Common Client Interface (CCI), which together deliver JCA the electricity to access information in organization structures.

Q23. What Is Java Ee Connector Architecture (jca) ?

(JCA) is a Java-primarily based generation answer for connecting software servers and business enterprise records systems (EIS) as a part of organization software integration (EAI) solutions. While JDBC is specifically used to attach Java EE packages to databases, JCA is a extra prevalent structure for connection to legacy structures. JCA became advanced beneath the Java Community Process as JSR sixteen (JCA 1.0), JSR 112 (JCA 1.5) and JSR 322 (JCA 1.6).

Q24. What Is Limitations Of The Jca 1.0 And Its Future?

The JCA, as its unmarried biggest weak spot, lacks an asynchronous communique car. As a effect, pulling records out of an EIS proves truthful, however having an EIS ship data (for instance records updates) to your device isn't always presently inside the JCA specification.

In every other essential weak spot, the JCA specification lacks a common API for facts get admission to. The CCI cited above is elective, so no dependable mechanism exists that a developer can use to get entry to records using JCA (only the machine contracts are assured to be consistent).

The excellent information is that maximum of the contemporary JCA's barriers will be addressed inside the specification's next model, JCA 2.0, currently in improvement as JSR (Java Specification Request) 1@Version 2.Zero will deal with asynchronous talents, JMS integration with JCA, metadata for the CCI layer, and XML use inside the CCI layer.

Q25. What Is Bootstrap Contexts?

The Bootstrap Contexts tab contains the listing of configured Bootstrap Contexts. New Bootstrap Context objects can be delivered, removed, and configured. Each Bootstrap Context have to be assigned a Work Manager.

Q26. What Is The Procedure To Configure The Jca Subsystem Using The Management Console?

The JCA subsystem of JBoss Enterprise Application Platform 6 may be configured within the Management Console. The JCA configuration alternatives are located in barely different locations in the Management Console depending on how the server is being run.

If the server is going for walks as a Standalone Server, observe these steps:

Click at the Profile link on the top proper to replace to the Profile view.

Ensure the Profile section in the navigation panel to the left is multiplied.

Click on Connector to make bigger it, and then click on JCA.

If the server is going for walks as a part of a Managed Domain, observe these steps:

Click at the Profile hyperlink at the top right to replace to the Profile view

Select the profile you are modifying from the Profile menu at the top of the navigation panel at the left.

Click on Connector to make bigger it, after which click on on JCA.

Configure the settings for the JCA subsystem the use of the 3 tabs.

Q27. What Is Resource Adapters In Jca?

Most EAI vendors encompass proprietary adapters built to work with their merchandise. Most proprietary adapters allow for synchronous and asynchronous communication to an EIS. JCA adapters closely resemble those adapters, except JCA adapters include handiest a synchronous conversation channel. Resource adapters constitute the EAI feature JCA maximum directly suits, even though most EAI companies' adapters provide a bigger function set (for instance asynchronous capability) than JCA adapters.

Q28. What Is Bootstrap Contexts?What Are Bootstrap Context Attributes?

Bootstrap contexts: Used to outline custom bootstrap contexts.

Attributes:

name:Specifies the name of the bootstrap context.

Workmanager:Specifies the call of the paintings supervisor to apply for this context.

Q29. What Is Traction Management Contract?

The traction control contract controls tractions in  unique methods. First, it lets in disbursed tractions, which provide a mechanism to propagate tractions that originate from inner an application server to an EIS system.

For example: in an EJB, a traction may be created. If this EJB then employs a JCA useful resource adapter, the traction management settlement enables the traction to propagate to the EIS (thru the application server invoking the aid adapter's X/Open XA interfaces). In that state of affairs, the traction supervisor on the utility server could control a couple of sources to behavior allotted traction coordination (i.E., two-phase dedicate).

Second, the traction management agreement can manage tractions by using creating nearby tractions. Local tractions are local in the experience that they exist simplest on a particular EIS aid. The traction agreement lets in those tractions to be managed, however they're associated with any traction that exists on the utility server in which the JCA useful resource adapter is running.

Also observe that the useful resource adapter want not put in force the the traction control agreement. Making this elective allows for resource adapters in non traction resources.