SCJA certification
All articles for SCJA certification
Tips and How Tos for SCJA certification
Java 2 Platform Micro Edition (J2ME)
in SCJA
J2ME stands for Java 2 Micro Edition. This platform of Java is used to develop applications for resource constraint devices such as mobile phones, PDAs, set top boxes, etc.
The J2ME comprises three major components. These components are as follows:
Configuration Profile
Optional...
continue reading " Java 2 Platform Micro Edition (J2ME)" »
String Handling
in SCJA
The String class is defined in the java.lang package and hence is implicitly available to all the programs in Java. The String class is declared as final, which means that it cannot be subclassed. It extends the Object class and implements the Serializable, Comparable, and CharSequence...
continue reading " String Handling" »
How are message driven beans different from session beans and entity beans?
in SCJA
A message-driven bean is a type of EJB (Enterprise JavaBean) that provides asynchronous communication. A message-driven bean's instance handles only one client message at a time, which is short-lived. The message from the client arrives through JMS (Java Message Service) and is transferred to the...
continue reading "How are message driven beans different from session beans and entity beans?" »
How are packages declared?
in SCJA
Packages are declared by using the package statement. The word package is a keyword in Java. The package statement is not technically needed to write a complete Java program. However, if it appears, it must be the first executable statement in the program. Only comments or white spaces are...
continue reading "How are packages declared?" »
How many packages are included in JNDI?
in SCJA
JNDI is divided into 5 packages as follows: javax.naming: It contains classes and interfaces for accessing naming services. It defines the Context interface and the Initial Context Class. javax.naming.directory: It provides the additional directory services. It defines the DirContext...
continue reading "How many packages are included in JNDI?" »
How to install an RMI application?
in SCJA
Take the following steps to install an RMI application: Place the following files on the server: Remote Interface (Factorial.java) Remote object (FactorialImpl.java) Server (FactorialServer.java) Compile all the files by using the javac command.
On the server, generate the stubs and...
continue reading "How to install an RMI application?" »
Java Message Service
in SCJA
JMS, which stands for Java Message Service, is also referred to as Messaging Oriented Middleware (MOM). It defines standards for reliable enterprise messaging. As JDBC provides access to many different relational databases, in the same way, JMS provides vendor-neutral access to enterprise...
continue reading "Java Message Service" »
Java-Data types, Variables, and Arrays
in SCJA
Java is a robust language. One of the factors, which makes Java robust is the fact that it is a strongly typed language, i.e., every variable has a type, every expression has a type, and every type is defined.
Java defines eight primitive data types. These are as follows: int byte long...
continue reading "Java-Data types, Variables, and Arrays" »
JDBC
in SCJA
The introduction of the Java language is required before introducing the concept of JDBC. Java is an object-oriented programming language. It incorporates all the objected-oriented concepts such as polymorphism, abstraction, encapsulation, etc. Java is a platform independent language because it...
continue reading "JDBC" »
Multi-Tier Applications in Java
in SCJA
A multi-tier application is a distributed application that is hosted by different machines for creating enterprise applications. The functionality of the tier is divided into isolated functional areas and these functional areas are known as tiers. A multi-tier application consists the following...
continue reading "Multi-Tier Applications in Java" »