JAVA Interview Questions and Answers - DoAnswers.com

Java is a programming language expressly designed for use in the distributed environment of the Internet. It was designed to have the "look and feel" of the C++ language, but it is simpler to use than C++ and enforces an object-oriented programming model. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. It can also be used to build a small application module or applet for use as part of a Web page. Applets make it possible for a Web page user to interact with the page. The major characteristics of Java are: The programs you create are portable in a networkThe code is robust.Java is object-oriented.In addition to being executed at the client rather than the server, a Java applet has other characteristics designed to make it run fast. Relative to C++, Java is easier to learn. (However, it is not a language you'll pick up in an evening!) Java was introduced by Sun Microsystems in 1995 and instantly created a new sense of the interactive possibilities of the Web. Both of the major Web browsers include a Java virtual machine. Almost all major operating system developers (IBM, Microsoft, and others) have added Java compilers as part of their product offerings. The Java virtual machine includes an optional just-in-time compiler that dynamically compiles bytecode into executable code as an alternative to interpreting one bytecode instruction at a time. In many cases, the dynamic JIT compilation is faster than the virtual machine interpretation.

Java Interviews are getting tough these days as the technology grows faster. To get through the Java interview one needs to update him/herself in a regular manner. Having said that, just before the interview, it is very important to have a quick glance of the reputed Java questions and answers to make yourself comfortable during the interview process. This is where DoAnswers.com helps you in renewing yourself on Java and various other technologies interview preparation.

Core Java Interview Questions and Answers

Java is a programming language expressly designed for use in the distributed environment of the Internet. It was designed to have the "look and feel" of the C++ language, but it is simpler to use than C++ and enforces an object-oriented programming model. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. It can also be used to build a small application module or applet for use as part of a Web page. Applets make it possible for a Web page user to interact with the page. The major characteristics of Java are: The programs you create are portable in a networkThe code is robust.Java is object-oriented.In addition to being executed at the client rather than the server, a Java applet has other characteristics designed to make it run fast. Relative to C++, Java is easier to learn. (However, it is not a language you'll pick up in an evening!) Java was introduced by Sun Microsystems in 1995 and instantly created a new sense of the interactive possibilities of the Web. Both of the major Web browsers include a Java virtual machine. Almost all major operating system developers (IBM, Microsoft, and others) have added Java compilers as part of their product offerings. The Java virtual machine includes an optional just-in-time compiler that dynamically compiles bytecode into executable code as an alternative to interpreting one bytecode instruction at a time. In many cases, the dynamic JIT compilation is faster than the virtual machine interpretation.

Core Java Interviews are getting tough these days as the technology grows faster. To get through the Core Java interview one needs to update him/herself in a regular manner. Having said that, just before the interview, it is very important to have a quick glance of the reputed Core Java questions and answers to make yourself comfortable during the interview process. This is where DoAnswers.com helps you in renewing yourself on Core Java and various other technologies interview preparation.

Java Platform, Micro Edition (Java ME) Interview Questions And Answers

Java ME Platform represents the only truly open solution for building mobile applications for the industry. The technology allows portability of applications between platforms and investments are kept to a minimum through the possibility of reuse. The continuous platform evolution is driven by the increasing demands for capabilities and performance in the industry and assured through the definition of the platform components and APIs in the Java Community Process. The fact that the technology is open for anyone to use the community of developers creating applications for the platform is large and increasing. This assures the continuous improvement and availability of applications for the platform which in turn drives business for everybody involved in the eco-system. On top of this the platform itself represents a high performance and secure platform for mobile applications. The Java ME technology ecosystem evolves around a number of different players in the industry, all of them participating in , and influencing, the continuous improvement of the technology and platform. The end users are constantly demanding new features and capabilities to their services. The content developers adopts the user requirements and creates new appealing services with new capabilities. The OEMs creates new capable devices to host the new services and features and also creates new demands by presenting new capabilities to the end users. Carriers creates the mobile environment to host and deploy services on and also drives the exploration of new business-driving services to the end users. This constant evolution of demands and capabilities is the single most important reason for the success of the Java platform and ensures it will continue to evolve into the future needs of everyone involved in the eco-system.

JAVA GUI Interview Questions and Answers

The Java Foundation Classes (JFC) are a set of Java class libraries provided as part of Java 2 Platform, Standard Edition (J2SE) to support building graphics user interface (GUI) and graphics functionality for client applications that will run on popular platforms such as Microsoft Windows, Linux, and Mac OSX

Swing Interviews are getting tough these days as the technology grows faster. To get through the Swing interview one needs to update him/herself in a regular manner. Having said that, just before the interview, it is very important to have a quick glance of the reputed Swing questions and answers to make yourself comfortable during the interview process. This is where DoAnswers.com helps you in renewing yourself on Swing and various other technologies interview preparation.

Java Performance Tuning Interview Questions And Answers

J2SE 5.0 includes a number of new features and enhancements to improve performance in many areas of the platform. Improvements to new language features include: additions to the virtual machine, enhancements to the base and integration libraries, the user interface, deployment, tools and architectures, and OS & hardware platforms. Enhancements to program execution speed include: Garbage collection ergonomics, StringBuilder class, Java 2D technology enhancements, and performance and memory usage improvements to image I/O.

JUnit Interview Questions And Answers

JUnit is the de facto standard unit testing library for the Java language. JUnit 4 is the first significant release of this library in almost three years. It promises to simplify testing by exploiting Java 5's annotation feature to identify tests rather than relying on subclassing, reflection, and naming conventions. In this article, obsessive code tester Elliotte Harold takes JUnit 4 out for a spin and details how to use the new framework in your own work. Note that this article assumes prior experience with JUnit.

JUnit, developed by Kent Beck and Erich Gamma, is almost indisputably the single most important third-party Java library ever developed. As Martin Fowler has said, "Never in the field of software development was so much owed by so many to so few lines of code." JUnit kick-started and then fueled the testing explosion. Thanks to JUnit, Java code tends to be far more robust, reliable, and bug free than code has ever been before. JUnit (itself inspired by Smalltalk's SUnit) has inspired a whole family of xUnit tools bringing the benefits of unit testing to a wide range of languages. nUnit (.NET), pyUnit (Python), CppUnit (C++), dUnit (Delphi), and others have test-infected programmers on a multitude of platforms and languages.

However, JUnit is just a tool. The real benefits come from the ideas and techniques embodied by JUnit, not the framework itself. Unit testing, test-first programming, and test-driven development do not have to be implemented in JUnit, any more than GUI programming must be done with Swing. JUnit itself was last updated almost three years ago. Although it's proved more robust and longer lasting than most frameworks, bugs have been found; and, more importantly, Java has moved on. The language now supports generics, enumerations, variable length argument lists, and annotations--features that open up new possibilities for reusable framework design.

JUnit's stasis has not been missed by programmers who are eager to dethrone it. Challengers range from Bill Venners's Artima SuiteRunner to Cedric Beust's TestNG. These libraries have some features to recommend them, but none have achieved the mind or market share held by JUnit. None have broad out-of-the-box support in products like Ant, Maven, or Eclipse. So Beck and Gamma have commenced work on an updated version of JUnit that takes advantage of the new features of Java 5 (especially annotations) to make unit testing even simpler than it was with the original JUnit. According to Beck, "The theme of JUnit 4 is to encourage more developers to write more tests by further simplifying JUnit." Although it maintains backwards compatibility with existing JUnit 3.8 test suites, JUnit 4 promises to be the most significant innovation in Java unit testing since JUnit 1.0.

Remote Method Invocation (RMI) Interview Questions And Answers

Java Remote Method Invocation (Java RMI) enables the programmer to create distributed Java technology-based to Java technology-based applications, in which the methods of remote Java objects can be invoked from other Java virtual machines, possibly on different hosts. RMI uses object serialization to marshal and unmarshal parameters and does not truncate types, supporting true object-oriented polymorphism.

Unified Modeling Language (UML) Interview Questions And Answers

The Unified Modeling Language (UML) is a graphical language for visualizing, specifying, constructing, and documenting the artifacts of a software-intensive system. The Unified Modeling Language offers a standard way to write a system's blueprints, including conceptual things such as business processes and system functions as well as concrete things such as programming language statements, database schemas, and reusable software components.