J2ME Interview Questions

What is J2ME

Java 2, Micro Edition is a group of specifications and technologies that pertain to Java on small devices. The J2ME moniker covers a wide range of devices, from pagers and mobile telephones through set-top boxes and car navigation systems. The J2ME world is divided into configurations and profiles, specifications that describe a Java environment for a specific class of device.

What is J2ME WTK

The J2ME Wireless Toolkit is a set of tools that provides developers with an emulation environment, documentation and examples for developing Java applications for small devices. The J2ME WTK is based on the Connected Limited Device Configuration (CLDC) and Mobile Information Device Profile (MIDP) reference implementations, and can be tightly integrated with Forte for Java

What is API

An Application Programming Interface (API) is a set of classes that you can use in your own application. Sometimes called libraries or modules, APIs enable you to write an application without reinventing common pieces of code. For example, a networking API is something your application can use to make network connections, without your ever having to understand the underlying code.

What is CDC

The Connected Device Configuration (CDC) is a specification for a J2ME configuration. Conceptually, CDC deals with devices with more memory and processing power than CLDC; it is for devices with an always-on network connection and a minimum of 2 MB of memory available for the Java system

What is CLDC

The Connected, Limited Device Configuration (CLDC) is a specification for a J2ME configuration. The CLDC is for devices with less than 512 KB or RAM available for the Java system and an intermittent (limited) network connection. It specifies a stripped-down Java virtual machine1 called the KVM as well as several APIs for fundamental application services. Three packages are minimalist versions of the J2SE java.lang, java.io, and java.util packages. A fourth package, javax.microedition.io, implements the Generic Connection Framework, a generalized API for making network connections.

What is MIDP

The Mobile Information Device Profile (MIDP) is a specification for a J2ME profile. It is layered on top of CLDC and adds APIs for application life cycle, user interface, networking, and persistent storage. What is configuration
In J2ME, a configuration defines the minimum Java runtime environment for a family of devices: the combination of a Java virtual machine (either the standard J2SE virtual machine or a much more limited version called the CLDC VM) and a core set of APIs. CDC and CLDC are configurations. See also profile, optional package.

What is Foundation Profile

The Foundation Profile is a J2ME profile specification that builds on CDC. It adds additional classes and interfaces to the CDC APIs but does not go so far as to specify user interface APIs, persistent storage, or application life cycle. Other J2ME profiles build on the CDC/Foundation combination: for example, the Personal Profile and the RMI Profile both build on the Foundation Profile.

What is Generic Connection Framework

The Generic Connection Framework (GCF) makes it easy for wireless devices to make network connections. It is part of CLDC and CDC and resides in the javax.microedition.io package.

What is GPRS

The General Packet Radio System (GPRS) is the next generation of GSM. It will be the basis of 3G networks in Europe and elsewhere.

What is HTTPS

Hyper Text Transfer Protocol Secure sockets (HTTPS) is a protocol for transmission of encrypted hypertext over Secure Sockets Layer.

What is Java Card

The Java Card specification allows Java technology to run on smart cards and other small devices. The Java Card API is compatible with formal international standards, such as, ISO7816, and industry-specific standards, such as, Europay/Master Card/Visa (EMV

What is JCP

The Java Community Process (JCP) an open organization of international Java developers and licensees who develop and revise Java technology specifications, reference implementations, and technology compatibility kits through a formal process.

What is JSR

Java Specification Request (JSR) is the actual description of proposed and final specifications for the Java platform. JSRs are reviewed by the JCP and the public before a final release of a specification is made

What is kSOAP

kSOAP is a SOAP API suitable for the J2ME, based on kXML.

What is kXML

The kXML project provides a small footprint XML parser that can be used with J2ME.

What is LCDUI

LCDUI is a shorthand way of referring to the MIDP user interface APIs, contained in the javax.microedition.lcdui package. Strictly speaking, LCDUI stands for Liquid Crystal Display User Interface. It's a user interface toolkit for small device screens which are commonly LCD screens.

What is MIDlet

A MIDlet is an application written for MIDP. MIDlet applications are subclasses of the javax.microedition.midlet.MIDlet class that is defined by MIDP.

What is MIDlet suite

MIDlets are packaged and distributed as MIDlet suites. A MIDlet suite can contain one or more MIDlets. The MIDlet suite consists of two files, an application descriptor file with a .jad extension and an archive file with a .jar file. The descriptor lists the archive file name, the names and class names for each MIDlet in the suite, and other information.

What is Obfuscation

Obfuscation is a technique used to complicate code. Obfuscation makes code harder to understand when it is de-compiled, but it typically has no affect on the functionality of the code. Obfuscation programs can be used to protect Java programs by making them harder to reverse-engineer.

What is optional package

An optional package is a set of J2ME APIs providing services in a specific area, such as database access or multimedia. Unlike a profile, it does not define a complete application environment, but rather is used in conjunction with a configuration or a profile. It extends the runtime environment to support device capabilities that are not universal enough to be defined as part of a profile or that need to be shared by different profiles. J2ME RMI and the Mobile Media RMI are examples of optional packages.

What is OTA

Over The Air (OTA) refers to any wireless networking technology.
What is Personal Profile
The Personal Profile is a J2ME profile specification. Layered on the Foundation Profile and CDC, the Personal Profile will be the next generation of PersonalJava technology. The specification is currently in development under the Java Community Process (JCP).

What is PNG

Portable Network Graphics (PNG) is an image format offering lossless compression and storage flexibility. The MIDP specification requires implementations to recognize certain types of PNG images.

What is RMS

The Record Management System (RMS) is a simple record-oriented database that allows a MIDlet to persistently store information and retrieve it later. Different MIDlets can also use the RMS to share data.

What is SDK

A Software Development Kit (SDK) is a set of tools used to develop applications for a particular platform. An SDK typically contains a compiler, linker, and debugger. It may also contain libraries and documentation for APIs.

What is SMS

Short Message Service (SMS) is a point-to-point service similar to paging for sending text messages of up to 160 characters to mobile phones

What is WMA

The Wireless Messaging API (WMA) is a set of classes for sending and receiving Short Message Service messages. See also SMS.

What is the difference between MIDP 1.0 and MIDP 2.0?

Full Canvas will work in MIDP 2.0but not possible in MIDP 1.0
Push Registry is added in MIDP 2.0but not possibly in MIDP 1.0
Game API added in MIDP 2.0not added in the MIDP 1.0

What is the difference between CLDC 1.0 and CLDC 1.1?

CLCD 1.0 does not have support for floating points whileCLDC 1.1 does.

What is 3G?

Third generation (3G) wireless networks will offer faster data transfer rates than current networks. The first generation of wireless (1G) was analog cellular. The second generation (2G) is digital cellular, featuring integrated voice and data communications. So-called 2.5G networks offer incremental speed increases. 3G networks will offer dramatically improved data transfer rates, enabling new wireless applications such as streaming media.
What is WAP Wireless Application Protocol (WAP) is a protocol for transmitting data between servers and clients (usually small wireless devices like mobile phones). WAP is analogous to HTTP in the World Wide Web. Many mobile phones include WAP browser software to allow users access to Internet WAP sites.

Refrences
http://techpreparation.com/computer-interview-questions/j2me-interview-questions-answers6.htm
http://www.allinonetech.co.in/J2ME.php
http://www.geocities.com/j2me_interviewquestion/

Mobile Application Experience

i have worked in mobile application development using J2ME for 2 years and this is sample of my work

• Mobile VNC Viewer this is really my graduation project and its is a client for VNC (http://www.realvnc.com/) that which allows you to view and interact with one computer anywhere on the Internet taking into attention limitation of mobile device (network bandwidth, mobile processing speed, different resolution of mobile and PC).
  VNC is an open source project developed in Cambridge university –EnglandVNC stands for Virtual Network Computing. It is remote control software which allows you to view and interact with one computer (the "server") using a simple program (the "viewer") on another computer anywhere on the Internet. The two computers don't even have to be the same type, so for example you can use VNC to view an office Linux machine on your Windows PC at home. VNC is freely and publicly available and is in widespread active use by millions throughout industry, academia and privately.
  

Mobile VNC Features

• 1.Remote Desktop
• 2.soft mouse and keyboard
• 3.file transfer from remote pc to another remote pc
• 4.file viewer to minimize network bandwidth and cost
• 5.save your configuration