#Jsf icefaces interview questions update

Good practice is to create it when the application is initialized.ĩ. It holds cached data that has been read in one unit of work and may be reused in a future unit of work. Yes: that is many threads can access it cuncurrentely and request for sessions. It’s retrieved by the SessionFactory’s openSession() method This interface is a single threaded object which represents a single unit of work with application and persistent database. The Session interface wraps a JDBC Connection. Which Hibernate object wraps the JDBC Connection? But no transaction control, no instance pooling, no concurrency control, and certainly no security.ħ. Quick and dirty, this means you can store an object tree belonging to an class hierarchy in a relational DB without writing a single SQL query. Hibernat is “just” an ORM (Object/Relational Mapping) tool. This services are, among others, transactions, concurrent access control, security, instance pooling, etcetera. All of this in order to allow a container (JBoss, Weblogic, etc.) to provide services to those components, and to be able to reuse and distribute this components. The perception of EJB3 as being a simple clone of Hibernate is primarily based on developer familiarity with Hibernate and a similarity of naming, as well as common purpose, and that Hibernate is morphing itself into an EJB3 implementation based on the work going into the specification, not the other way around.ĮJBs are supposed to be components, in the sense that they’re not just one class, but a set of classes, descriptors and usage and management contracts.

What is the difference between Hibernate and EJB 3? Do not you think EJB 3 is just a clone of Hibernate? ? The Java Transaction API consists of three elements: a high-level application transaction demarcation interface, a high-level transaction manager interface intended for an application server, and a standard Java mapping of the X/Open XA protocol intended for a transactional resource manager.Ħ.

#Jsf icefaces interview questions update

? The Java™ Transaction API (JTA) allows applications to perform distributed transactions, that is, transactions that access and update data on two or more networked computer resources. ? Java Transaction API (JTA) specifies standard Java interfaces between a transaction manager and the parties involved in a distributed transaction system: the resource manager, the application server, and the transactional applications. Using Joss JMX agents and monitoring the deployed components to the application server involves in the first step.Īfter finding the most of the time spent by specific components or libraries or most of the resources, one can use Jprobe a specialized tool for examining the single object or the objects loaded in the memory. This step is to find where the degradation is, whether it is external or internal and where is the appliciation spending all the time.

How do you monitor JBoss and detect the bottleneck of an application?ĭifferent components of the application are to be measured. This feature is provided by the JBoss jBPM process designer.Ĥ. The business process is graphically represented to facilitate a strong link between the business analyst and technical developer. The combination of workflow applications development with process design is a feature of JBoss jBPM. Enabling the creation of business processes that coordinates between people, applications and services is the functionality of BPM engine. JBoss decreases the network traffic and increases the scalability of applications by eliminating unnecessary database acces.Fully transactional features and highly configurable set of options which are to deal with concurrent data access, are provided by JBoss cache in an efficient manner possible for the applications. Frequently accessed Java objects are cached by utilzing JBoss cache to improve the performance of e-business applications. JBoss supports JNDI, Servlet/JSP (Tomcat or Jetty), EJB, JTS/JTA, JCA, JMS, Clustering (JavaGroups), Web Services (Axis), and IIOP integration (JacORB). It runs under any JVM of 1.3 or later versions. It was embedded with Apache Tomcat web server. Being JEE based, the JBoss supports cross-platform java applications. JBoss is a popular open source application server based on JEE technology.