The new HashMap group is approximately comparable to Hashtable, besides it’s unsynchronized and it permits nulls

Earliest adaptation step 1

Difference in HashMap and HashTable? (HashMap lets null philosophy given that key and value whereas Hashtable does not allow). HashMap cannot make certain your order of one’s chart commonly continue to be ongoing through the years.

Define form of Organization Beans? Session kidney beans -> Of the a customer and you will possess says getting a person Entity Beans -> Represents particular organization into the chronic shop including a databases

What is enterprise bean? ? Machine front reusable coffee part ? Even offers functions that are hard to pertain by the programmer ? Sun: Firm Bean buildings is part tissues into implementation and you can growth of role-situated delivered providers programs. Apps authored having fun with enterprise coffees kidney beans try scalable, transactional and you can multi-user secure. These types of software could be written after following implemented with the one server plattform that supporting company coffee kidney beans specs. ? Firm pink cupid Гјcretsiz uygulama beans are carried out of the J2EE host.

Organization Kidney beans ? Signifies that line regarding databases

0 contained tutorial beans, organization kidney beans just weren’t included. Organization kidney beans were put into version 1.step 1 and therefore came out throughout the 12 months 1999. Latest launch was EJB adaptation 1.2

Attributes out-of EJB? Database administration –Database connection pooling –DataSource, provided by the fresh J2EE server. Needed seriously to supply union pool of your servers. –Databases availability was configured into the J2EE server -> easy to changes database / databases driver Purchase management –Marketed deals –J2EE servers also provides exchange display screen that is reached from the customer. Safety administration –Authetication –Consent –security Corporation coffee beans will be delivered /replicated into the independent computers

lDistribution/duplication offers –Weight controlling, weight should be split into independent host. –Failover, if a person servers fails, other people could well keep towards handling typically. –Show, you to definitely server isn’t therefore heavier piled. Along with, eg Weblogic keeps thread swimming pools to have boosting performance in a single server.

When you should prefer EJB? Host was hefty piled –Distribution out-of server really helps to reach better abilities. Host must have imitation to your matter of incapacity of 1 machine. –Replication try undetectable into designer Distributed transactions are needed –J2EE server also offers purchase display that takes proper care of deal management. –Distributed purchases are hidden to the programmer ? Most other services versus. currency Weblogic J2EE host

Have you thought to to make use of 100 % free J2EE host? –no tecnical service –more challenging to use (zero interface . ) –zero combination to help you development gadgets (eg, Jbuilder) –Pests? Other problems while in the enterprise?

Alternative:Tuxedo ? Tuxedo try an excellent middleware which provides scalability functions and you may transaction monitors. ? C otherwise C++ built. ? Can be used with Java consumer by classes in JOLT bundle offered by BEA. Quicker one J2EE servers?

J2EE machine now offers ? DataSource. –Target that can be used to attain database relationship regarding the relationship pool. –Would be reached from the screen DataSource ? Transaction display –Are utilized of the interface UserTransaction. ? Coffees Naming additionally the List Solution

Coffee Naming plus the Directory Solution ? Naming service is needed to to acquire kidney beans domestic connects and other things (DataSource, UserTransaction) –Such as, jndi title of your DataSource ? Index provider is required to store and you may access features of the the identity. –jndi title: java:comp/env/propertyName

XML – implementation descriptor ejb-jar.xml + server-particular xml- document That’s after that Packaged when you look at the a jar – file in addition to bean groups. Beans try packaged on EJB Container document , Manifest file can be used in order to number EJB’s and container document carrying Implementation descriptor.

Example Bean Developer applications about three categories: –Household interface, consists of tricks for carrying out (and locating to possess entity kidney beans) bean hours. –Remote user interface, include providers tips the bean also provides. –Bean class, provides the business logic of firm bean.