First adaptation step one
Difference in HashMap and HashTable? (HashMap lets null values since trick and value whereas Hashtable does not allow). HashMap doesn’t make certain the transaction of map often are still lingering through the years.
Establish brand of Enterprise Kidney beans? Session kidney beans -> On the an individual and you can features states having a client Organization Kidney beans -> Is short for some organization inside persistent storage eg a database
What is actually enterprise bean? ? Host front side reusable coffees component ? Also provides characteristics that are hard to implement from the designer ? Sun: Business Bean buildings is a component tissues towards the implementation and you may development of part-oriented distributed business programs. Apps created using business coffees beans are scalable, transactional and multiple-member safer. These programs are authored after and deployed for the one machine plattform one helps enterprise coffees kidney beans specs. ? Organization beans are performed by J2EE servers.
Entity Beans ? Is short for you to line on the databases
0 contains concept beans, entity beans just weren’t integrated. Entity kidney beans was in fact put in variation step one.1 and that showed up through the season 1999. Current discharge was EJB version 1.dos
Functions away from EJB? Databases management –Database partnership pooling –DataSource, given by the newest J2EE host. Wanted to availableness partnership pool of the host. –Databases availableness is actually designed on J2EE servers -> simple to change databases / database driver Exchange management –Delivered deals –J2EE servers also provides exchange display which is accessed of the consumer. Security management –Authetication –Authorization –encryption Business coffee beans can be distributed /duplicated into the separate computers
lDistribution/replication also provides –Load balancing, stream will likely be divided in to independent machine. –Failover, if a person server goes wrong, anybody else are able to keep into the control generally speaking. –Results, you to definitely server isn’t so heavy piled. Including, such as Weblogic has actually bond pools for improving performance in a single server.
When to favor EJB? Machine might possibly be heavy loaded –Shipments from machine helps reach most readily useful results. Servers should have imitation to your case of inability of a single host. –Replication try hidden into designer Distributed transactions are expected –J2EE host also provides transaction display screen which takes care of purchase government. –Delivered purchases is actually invisible towards the programmer ? Most other attributes against. currency Weblogic J2EE server
Why-not to make use of 100 % free J2EE machine? –zero tecnical support –more difficult to utilize (no user interface . ) –zero consolidation in order to development products (for example, Jbuilder) –Pests? Other problems while in the project?
Alternative:Tuxedo ? Tuxedo are an excellent middleware that offers scalability characteristics and exchange inspections. ? C otherwise C++ based. ? May be used having Coffees consumer 
by the groups during the JOLT bundle given by BEA. Shorter you to J2EE server?
J2EE host also offers ? DataSource. –Target which you can use to achieve databases union regarding connection pond. –Can be accessed from the software DataSource ? Purchase display screen –Shall be utilized by the software UserTransaction. ? Coffees Naming therefore the Index Services
Java Naming therefore the List Service ? Naming solution must to track down kidney beans home connects or other items (DataSource, UserTransaction) –Like, jndi term of the DataSource ? Index solution must shop and recover qualities by the their title. –jndi name: java:comp/env/propertyName
XML – implementation descriptor ejb-container.xml + server-specific xml- document That’s upcoming Manufactured inside a container – document also bean groups. Kidney beans is actually packed with the EJB Container document , Manifest file is employed so you can listing EJB’s and container document holding Deployment descriptor.
Course Bean Designer programs about three groups: –House screen, includes suggestions for doing (and you may discovering for entity kidney beans) bean period. –Secluded software, contains organization procedures new bean offers. –Bean class, gets the organization logic of organization bean.