There are three basic classifications of patterns Creational, Structural, and Behavioral patterns. Creational Patterns • Abstract Factory:- Creates an instance of several families of classes • Builder: – Separates object construction from its representation • Factory Method:- Creates an instance of several derived classes • Prototype:- A fully initialized instance to be copied or cloned • Singleton:- A class in [...]

User log4j and commons-logging.jar in the class path. These jar files contain the information for logging set up.Declare the following as a class attribute in the class where you want to implement the logging, say SomeClass.java You would have a sample log4j properties configuration file which you should put in your classpath. Suppose you wanted the [...]

HashMap vs Hashtable Hashtable and HashMap are both key-value based data structure. Both of them allows the access data based on key. Both of them some differences in storing values and performance over iteration. Some of the basic differences are following HashMap HashTable Synchronized Un-synchronized  Synchronized Allow null Allowed Null for key and Value Not allowed, Null pointer would [...]

Hi all , here again I came up with most awaited article .This is part oracle Adf interview Question part-two.I have accumulated ,formulated, and gathered these information from various sources.So that it would be helpful for Oracle ADF community. But I am afraid of Mr. Saravanan of jdeveloperandadf.blogspot.com ,who again not try to copy paste [...]

The factory method pattern is an object-oriented design pattern to implement the concept of factories. Like other creational patterns, it deals with the problem of creating objects (products) without specifying the exact class of object that will be created. The creation of an object often requires complex processes not appropriate to include within a composing [...]

Task Flow- ADF Task Flows is a new feature that will ship with ADF 11g. In simple terms, it is a tool to encapsulate page flow/navigation. A set of ADF Controller activities, control flow rules and managed beans that interact to allow a user to complete a task. It is much more than that in [...]

It is very common to use unique identifiers in web application for identifying unique users or some other usage, till now I was always writing an program using some random generator code for them. It is always hard to do that, as those unique identifiers should not repeat them self in future, else it will [...]

Q: What is a Thread? Ans) In Java, “thread” means two different things: An instance of class java.lang.Thread. A thread of execution. An instance of Thread is just…an object. Like any other object in Java, it has variables and methods, and lives and dies on the heap. But a thread of execution is an individual [...]

The Singleton Pattern Ensure a class only has one instance, and provide a global point of access to it.For example ,if we need a connection to single database at one time  or when ever we are referring to to single application.properties file in struts application for showing application in one language at one time.Then we [...]

1) What is servlet? Ans: Servlets are modules that extend request/response-oriented  servers, such as java-enabled web servers. For example, a servlet might be responsible for taking data in an HTML order-entry form and applying the business logic used to update a company’s order database. 2) What are the classes and  interfaces for servlets? Ans: There [...]