How to connect to a .NET Web Service from a J2ME MIDlet using kSOAP 2

Web services had and continue to have a great impact on the development of Web applications because they allow total independence between clients and service providers. The location, the platform, the programming language and the architecture of both the clients and the services has no effect on each other. The Internet technologies and standards that […]

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How to insert a logo or image into a QR code using Photoshop

This article describes different methods of changing a QR code in Photoshop that allow to insert a logo, image or text. The custom or branded QR code will be read correctly despite the modification. The QR (Quick Response code, Denso Barcode, ISO/IEC18004) code represents a two-dimensional code bar, initially used by industry, but widely used […]

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Android Tutorial (4) – Procedural vs. Declarative Design of User Interfaces

Android mobile applications are relying on user interfaces composed on dialog windows, visual controls, 2D graphics and other multimedia elements for efficiency and usability. The Android platforms allows programmers to use two methods to design user interfaces: procedural or declarative. In this post we develop a simple Android mobile applications that will help to make […]

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Android Tutorial – Overview and contents

The Android tutorial covers all important concepts that will allow a new programmer to learn how to develop mobile applications for the Android platform. The tutorial is written  from a programmer perspective and dives after few topics into simple and do-by-example applications which are easy to follow. Despite the apparently simplicity, each topic highlights important […]

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How to encrypt/decrypt files in Java with AES in CBC mode using Bouncy Castle API and NetBeans or Eclipse

The Bouncy Castle Crypto API for Java provides a lightweight cryptography API that is an alternative to the standard Sun Java Cryptographic Architecture (JCA) and Java Cryptographic Extension (JCE) bundled in the JDK. The API can be used in J2ME MIDlet applications or in other Java applications up to the 1.7 platform. The Bouncy Castle […]

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How to convert a byte array to a Hex String in Java

When processing binary values it is very difficult to read or to display them because any printing function generates a String value.  The problem with this approach is that not all byte values can be interpreted as a printable char (i.e. the 0 binary value represents the NUL symbol; for more details check ASCII Codes […]

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Android Tutorial (2) – Applications key concepts, activities and resources

In order to understand the Android application architecture you need some basic knowledge regarding Android applications key concepts. Understanding these elements will allow you to control: application components application lifecycle application resources In this post are described all these key concepts  in order to highlight their role, utility and importance. Other posts will describe in more […]

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Android Tutorial (01) – Setting the development environment

Android is an open source software toolkit created by Google and Open Handset Alliance. Initially developed for mobile phones, it has become a major application platform for a wide range of mobile devices. The scope of this post is to summarize the steps needed to set the development environment and to start learning and developing […]

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Tutorial Java SCJP – #19 Enumerated lists or Enums

There are logically situations in which a variable must have values restricted to a specific range or set that is defined in the solution specifications. Let’s imagine that you must develop a Java applications that manages Vehicles and the engine type must take one value from the {GASOLINE, DIESEL, HYBRID, ELECTRICAL} set. You can define […]

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Tutorial Java SCJP – #18 Initialization blocks

In order to process something you need values. And values are usually stored in static variables, local variables (defined in methods) or instance variables (nonstatic variables defined in classes). In order to initialize a variable you can do it at definition or later in a method (constructor or not). Despite these two common solutions, there […]

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J2ME tutorial – How to create and display forms and alerts

J2ME mobile applications are simple solutions that allow users to manage their data using different controls that are placed in forms, windows or Displayable. In the J2ME API, the equivalent of desktop applications windows is represented by a relative reduced set of forms which are subclasses of Displayable class. The entire framework is a limited, […]

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Tutorial Java SCJP – #17 Access modifiers for methods and attributes

Access modifiers represents ways to give or to restrict access to class variables and methods. One reason is the encapsulation concept that states that instance variables are not accessed directly, but only through access methods (prefixed with get or set). Another reason is to control how the class is used and how and what values […]

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