Free information about JAVA http://JAVA.e-articles.info/ en-us E-articles.info 2006 - 2010 Various high quality programming languages are used in the Software Industry. Some of them are expensive, while some are affordable by nature, however all of these are vastly used according to the client's requirement. Mainly three languages are used and they are http://JAVA.e-articles.info/title/Why-Java-programmers-are-taking-one-step-ahead-in-software-development-industry/ http://JAVA.e-articles.info/title/Why-Java-programmers-are-taking-one-step-ahead-in-software-development-industry/ Tue, 21 Jul 2009 00:33:17 GMT Like other programming languages java offers the control statements to control the execution of a program. The control statements in java are the selection statements, loop constructs and the jumping statements. The selection statements define the route of the execution considering different conditions. Loops control the iteration of one of more statements within a program considering specific conditions... http://JAVA.e-articles.info/title/SELECTION-STATEMENTS-IN-JAVA/ http://JAVA.e-articles.info/title/SELECTION-STATEMENTS-IN-JAVA/ Wed, 04 Mar 2009 01:41:22 GMT In today's highly competitive world, JAVA has become one of the most secure technologies for website and software development. Prime benefits of JAVA are platform independency and easy availability for users as it is an open source. JAVA is an object oriented programming language and it was intended to serve as a new way to manage software complexity. Java refers to a number of computer software products and specifications from Sun Microsystems that together provide a system for developing application software and deploying it in a cross-platform environment... http://JAVA.e-articles.info/title/JAVA-and-its-Advantages/ http://JAVA.e-articles.info/title/JAVA-and-its-Advantages/ Thu, 05 Feb 2009 02:49:27 GMT Get the right Knowledge Get the right Papers Get the right Direction Get the Money Hi, my name's Mark Bourne, I've focused mainly on Java because it's the hottest language right now and I've mastered it for as long as it's been around, to be more precise, I've gathered information, advices, guidelines and untold secrets from a few of the world's most successful Java Developers, Architects and Masterminds and I've put it all in one place, including my own personal experience of how I got rich programming in Java and how it enabled me to buy my first sports car at the age of 19. Ok here's the deal, as a Java developer, you can either work for a company for as long as you live and earn a decent salary, or follow a few steps and earn a fortune doing what you love, there are over 2 million Java Developers in the world, but only a few of those are actually wealthy, ever wondered why? I'll tell you why... http://JAVA.e-articles.info/title/Java-Tactics:-Earn-A-Fortune-With-Java/ http://JAVA.e-articles.info/title/Java-Tactics:-Earn-A-Fortune-With-Java/ Wed, 09 Jul 2008 03:57:32 GMT A listener in Java is an object that is used to handle events. In effect, it is implemented to listen for events and then tell the program the required information about that event, which you may then handle. For example, if the player moves the mouse, a listener will alert the program that the mouse has been moved and give details of its position, relative to the component currently occupying that area of the screen. The most commonly used event listeners are shown below and are found in the package java... http://JAVA.e-articles.info/title/What-are-Java-Listeners/ http://JAVA.e-articles.info/title/What-are-Java-Listeners/ Sun, 02 Sep 2007 04:23:37 GMT To use a package within a Java application or applet, we need to import it. We do this by means of the import keyword. So, for example, if we wish to include the I/O package, which is called java.io, we would have the following statement at the top of our code (before we define any classes): import java... http://JAVA.e-articles.info/title/Importing-Java-Packages/ http://JAVA.e-articles.info/title/Importing-Java-Packages/ Wed, 12 Dec 2007 05:31:42 GMT A Java package is a collection of related classes that can be imported into your program to support your software. They also provide namespace management, as well as access protection. Note :A namespace is the scope of the name of a variable. The following table shows some of the main packages that are included in the recent Java 1... http://JAVA.e-articles.info/title/What-is-a-Java-Package/ http://JAVA.e-articles.info/title/What-is-a-Java-Package/ Mon, 24 Dec 2007 06:39:47 GMT Invocation chaining means that you are not limited to merely accessing one class/object member in a given statement with the . operator but may continue to access further members in a given statement. For example, let's say that we wanted to convert an integer value to a String object representation and then retrieve the first digit from the string as a character. We might perform this task as follows: int i = 72; String str = String... http://JAVA.e-articles.info/title/Invocation-Chaining/ http://JAVA.e-articles.info/title/Invocation-Chaining/ Thu, 03 Jan 2008 07:47:52 GMT A regular expression is a code that is used to match a pattern in a given string and is new to Java 1.4. Regular expressions are made up of normal characters and metacharacters. Normal characters are like letters, numbers, underscores, etc... http://JAVA.e-articles.info/title/Regular-Expressions-in-Java/ http://JAVA.e-articles.info/title/Regular-Expressions-in-Java/ Wed, 02 Jan 2008 08:55:57 GMT The scope of a variable is the area in which a variable belongs, specified by the area in which it is declared. The following example code contains two declared variables, one inside a code block and one outside of that code block (imagine that the code is entered into a method, like main for example). int outside = 10; { int inside = 5; // outside is valid inside this code block inside = outside; } outside = 5; // inside cannot be accessed here The variable inside cannot be accessed anywhere outside the code block in which it was declared because it is out of the variable's scope. The variable inside simply does not exist outside of the code block... http://JAVA.e-articles.info/title/Variable-Scope/ http://JAVA.e-articles.info/title/Variable-Scope/ Sat, 29 Dec 2007 09:23:15 GMT Methods are used as the building blocks of your program, performing tasks that can be called again and again and using the same code to perform the task each time. The basic but fundamental parts of a method's declaration are its name, its return type, parameter signature, and code segment curly brackets. The following lines of code are an example of a method declaration. static void doSomething() { // add code here } This method is called doSomething and has a return type of void, which simply indicates that the method does not return a value... http://JAVA.e-articles.info/title/Java-Methods/ http://JAVA.e-articles.info/title/Java-Methods/ Sat, 29 Dec 2007 10:31:20 GMT The ability to choose the path that your program takes, based on any given data, is the key to all functionality in programming. In order to create conditional statements, we must first learn about the relational operators that we will use with these statements. The following table is a list of the relational operators in Java. Operator Returns true if… < Left operand is less than the right operand <= Left operand is less than or equal to the right operand == Operands are equal >= Left operand is greater than or equal to right operand > Left operand is greater than right operand != Operands are not equal The equality operator (==) is different from the other relational operators in that it can be used to test the value of any similar data types, such as two integer expressions, two Boolean expressions, or even two objects... http://JAVA.e-articles.info/title/Conditional-Statements/ http://JAVA.e-articles.info/title/Conditional-Statements/ Sat, 29 Dec 2007 11:39:25 GMT Character escape sequences allow for a character to be interpreted differently than its literal value. Character escape sequences are defined using the backslash (\) character, followed by the escape sequence code. The following table shows a list of character escape sequences with a description of what they do. Character Escape Sequence Description \b Backspace \f Form feed \n New line \r Carriage return \t Tab \u{hex} Unicode escape sequence \\ Backslash character... http://JAVA.e-articles.info/title/Character-Escape-Sequences/ http://JAVA.e-articles.info/title/Character-Escape-Sequences/ Sat, 29 Dec 2007 12:47:30 GMT The following table shows the standard bitwise operators in Java and a description of them. Operator Description & Bitwise AND | Bitwise inclusive-OR (generally known as OR) ^ Bitwise exclusive-OR (generally known as XOR) ~ Bitwise NOT To illustrate the function of these bitwise operators, we can use two byte values, A and B, which in java could be represented by a variable of type byte. The following table shows the binary notation of A and B (as there are 8 bits in a byte). Byte Binary Value A 01101010 B 11110000 The AND (&) operator tests two bits and returns the resulting bit true if both test bits are true; otherwise, the return bit is false... http://JAVA.e-articles.info/title/Bitwise-Operators/ http://JAVA.e-articles.info/title/Bitwise-Operators/ Thu, 03 Jan 2008 13:55:35 GMT The following assignment operators are similar to the increment and decrement operators that we have just seen. They are used so that you do not need to enter the source variable twice when assigning a value to a variable based on its current value. The following table shows a list of arithmetic assignment operators for the arithmetic operators: Operator Description *= Multiplication assignment /= Division assignment += Addition assignment –= Subtraction assignment %= Remainder assignment So we can set a value to a variable and then double its current value as follows: int number = 22; number *= 2; // all the fours, 44 In fact, it is possible to assign values to variables using the assignment operators wherever the value type is valid, even in mid-code, so to speak. int numberA = 30; int numberB = 7; numberA /= numberB -= 4; The last line of code first subtracts 4 from numberB, setting it to the value of 3... http://JAVA.e-articles.info/title/Arithmetic-Assignment-Operators/ http://JAVA.e-articles.info/title/Arithmetic-Assignment-Operators/ Thu, 03 Jan 2008 14:23:40 GMT Operator precedence deciphers the order in which calculations in an expression occur. Looking at the calculation example 3 + 4 * 6, the answer could be calculated by adding 3 and 4, which gives 7, and then multiplying 7 by 6, giving the answer of 42. However, we could also multiply 4 and 6 first, which gives 24, and then add on the 3, giving an answer of 27. The multiplication operator (*) actually has a higher precedence than the addition operator (+)... http://JAVA.e-articles.info/title/Operator-Precedence-in-programming-languages/ http://JAVA.e-articles.info/title/Operator-Precedence-in-programming-languages/ Thu, 03 Jan 2008 15:31:45 GMT The transition from a procedural programming (non-OOP) language to an object-oriented programming language is a large step for many programmers. It is true that both methods of programming can ultimately achieve the same goals, but you will find OOP is a neater and faster way to program, it is more suitable for teamwork, and programs are usually easier to design using the object-oriented approach. With OOP in Java, you will find that programming is challenging to begin with, yet very easy and very rewarding once you master it. What Is an Object? Objects are the building blocks that make up a program... http://JAVA.e-articles.info/title/Introduction-to-Object-Oriented-Programming-(OOP)/ http://JAVA.e-articles.info/title/Introduction-to-Object-Oriented-Programming-(OOP)/ Thu, 03 Jan 2008 16:39:50 GMT In a heterogeneous application and platform environment, IT managers are faced with different and often incompatible management frameworks. IT organizations often partition the heterogeneous platforms into groups of application "silos"subsystems with a common management infrastructure. Third-party products such as HP OpenView or CA Unicenter provide management consoles that consolidate the platform-specific management information and provide a common view of managed components. As for SOA, custom solutions from companies such as Infravio facilitate SLA compliance of deployed Web services... http://JAVA.e-articles.info/title/ISO-Management-Elements-in-Java-EE-.NET-Platforms/ http://JAVA.e-articles.info/title/ISO-Management-Elements-in-Java-EE-.NET-Platforms/ Wed, 28 Nov 2007 17:47:55 GMT The Java EE application program interface (API) consists of a suite of technology components and services that are used to build enterprise applications. It includes components that may be used to build presentation and business logic, APIs for managing business transactions, security and infrastructure tools to support the application operating environment, and tools for both internal and external integration. The following is a list of major technologies provided by Java EE. Enterprise Applications and Transactions Components Servlet, JavaServer Pages (JSP), Java Server Faces (JSF), and EJB are server-side components that are used to define presentation logic and business logic... http://JAVA.e-articles.info/title/Java-EE-Architecture/ http://JAVA.e-articles.info/title/Java-EE-Architecture/ Tue, 27 Nov 2007 18:55:15 GMT Java is a programming language. The Java EE Platform provides a runtime environment (also known as JRE or Java Runtime Environment) as well as a development kit (also known as JDK or Java Development Kit) for building applications in Java. There are a few variants of the platform: Java Platform, Standard Edition (Java SE) is the core of Java technology used mostly for application development. The runtime environment is widely used in Web browsers to run small applications known as applets... http://JAVA.e-articles.info/title/Java-EE-Platform/ http://JAVA.e-articles.info/title/Java-EE-Platform/ Tue, 27 Nov 2007 19:23:20 GMT This tutorial covers some common problems that you might encounter when writing Java applets. After each problem there is a list of possible solutions. Problem: Applet Viewer says there is no <APPLET> tag on my HTML page, but it really is there. Solution: Check whether you have a closing applet tag: </APPLET> Problem: I recompiled my applet, but my applet viewing application would not show the new version even though I told it to reload it... http://JAVA.e-articles.info/title/Common-Java-Applet-Problems/ http://JAVA.e-articles.info/title/Common-Java-Applet-Problems/ Sun, 10 Dec 2006 20:31:25 GMT You can deploy applets for users of both Internet Explorer and the Mozilla family of browsers in one of two ways: Through pure HTML Through JavaScript Using Pure HTML When using a pure HTML approach to deploy applets in a mixed-browser environment, note the following: 1. Internet Explorer Recognizes the object tag Ignores the contents of the comment tag 2. Mozilla browsers Ignore an object tag with the classid attribute Interpret the contents of the comment tag Consider the following example code from an HTML page: <object classid="clsid:CAFEEFAC-0016-0000-0000-ABCDEFFEDCBA" <param name="code" value="Applet1.class"> <comment> <embed code="Applet1... http://JAVA.e-articles.info/title/Deploying-Java-Applets-in-a-Mixed-Browser-Environment/ http://JAVA.e-articles.info/title/Deploying-Java-Applets-in-a-Mixed-Browser-Environment/ Wed, 09 Aug 2006 21:39:30 GMT How you deploy an applet depends on whether users access the Web page through the Internet or an Intranet, and the type of browser they use. Note this information about your users, then follow the general guidelines below. Deploying Applets on the Internet versus an Intranet When deploying applets: Use the applet tag if the Web page is accessed through the Internet or if it is accessed through an Intranet in which people use different browsers. Use the object or embed tag if the Web page is accessed through an Intranet and you know which browser people use... http://JAVA.e-articles.info/title/General-Java-Applet-Deployment-Considerations/ http://JAVA.e-articles.info/title/General-Java-Applet-Deployment-Considerations/ Fri, 04 Aug 2006 22:47:35 GMT Stop! Before you let the whole world know about your applet, make sure the answer to all of the following questions is yes: 1. Have you removed or disabled debugging output? Debugging output (generally created with System.out.println), while useful to you, is generally confusing or annoying to users... http://JAVA.e-articles.info/title/What-should-you-know-before-you-ship-your-Java-applet-~-The-perfectly-finished-applet/ http://JAVA.e-articles.info/title/What-should-you-know-before-you-ship-your-Java-applet-~-The-perfectly-finished-applet/ Fri, 18 Aug 2006 23:55:40 GMT An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions. Advantage 1: Separating Error-Handling Code from "Regular" Code Exceptions provide the means to separate the details of what to do when something out of the ordinary happens from the main logic of a program. In traditional programming, error detection, reporting, and handling often lead to confusing spaghetti code. For example, consider the pseudocode method here that reads an entire file into memory: readFile { open the file; determine its size; allocate that much memory; read the file into memory; close the file; } At first glance, this function seems simple enough, but it ignores all the following potential errors: • What happens if the file can't be opened? • What happens if the length of the file can't be determined? • What happens if enough memory can't be allocated? • What happens if the read fails? • What happens if the file can't be closed? To handle such cases, the readFile function must have more code to do error detection, reporting, and handling... http://JAVA.e-articles.info/title/Advantages-of-exceptions-in-Java-programming-language/ http://JAVA.e-articles.info/title/Advantages-of-exceptions-in-Java-programming-language/ Sun, 30 Jul 2006 01:23:45 GMT An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions. When an error occurs within a method, the method creates an object and hands it off to the runtime system. The object, called an exception object, contains information about the error, including its type and the state of the program when the error occurred. Creating an exception object and handing it to the runtime system is called throwing an exception... http://JAVA.e-articles.info/title/The-Three-Kinds-of-Exceptions-in-Java-applications/ http://JAVA.e-articles.info/title/The-Three-Kinds-of-Exceptions-in-Java-applications/ Tue, 07 Nov 2006 02:31:50 GMT The following rules define a simple strategy for creating immutable objects. Not all classes documented as "immutable" follow these rules. This does not necessarily mean the creators of these classes were sloppy they may have good reason for believing that instances of their classes never change after construction. However, such strategies require sophisticated analysis and are not for beginners... http://JAVA.e-articles.info/title/A-Strategy-for-Defining-Immutable-Objects-in-a-Java-application/ http://JAVA.e-articles.info/title/A-Strategy-for-Defining-Immutable-Objects-in-a-Java-application/ Tue, 24 Oct 2006 03:39:55 GMT In concurrent programming, there are two basic units of execution: processes and threads. In the Java programming language, concurrent programming is mostly concerned with threads. However, processes are also important. A computer system normally has many active processes and threads... http://JAVA.e-articles.info/title/Processes-and-Threads-in-Java-programming-language/ http://JAVA.e-articles.info/title/Processes-and-Threads-in-Java-programming-language/ Wed, 29 Nov 2006 04:47:15 GMT The process of writing a custom implementation follows: 1. Choose the appropriate abstract implementation class from the preceding list. 2. Provide implementations for all the class's abstract methods... http://JAVA.e-articles.info/title/Steps-to-follow-when-writing-a-custom-implementation/ http://JAVA.e-articles.info/title/Steps-to-follow-when-writing-a-custom-implementation/ Mon, 04 Dec 2006 05:55:20 GMT Many programmers will never need to implement their own Collections classes. Someday you might want to write your own implementation. It is fairly easy to do this with the aid of the abstract implementations provided by the Java platform. Before we discuss how to write an implementation, let's discuss why you might want to write one... http://JAVA.e-articles.info/title/Reasons-to-Write-a-Custom-Collection-Implementation-in-JAVA/ http://JAVA.e-articles.info/title/Reasons-to-Write-a-Custom-Collection-Implementation-in-JAVA/ Wed, 22 Nov 2006 06:23:25 GMT A collections framework is a unified architecture for representing and manipulating collections. All collections frameworks contain the following: Interfaces These are abstract data types that represent collections. Interfaces allow collections to be manipulated independently of the details of their representation. In object-oriented languages, interfaces generally form a hierarchy... http://JAVA.e-articles.info/title/Benefits-of-the-Java-Collections-Framework/ http://JAVA.e-articles.info/title/Benefits-of-the-Java-Collections-Framework/ Sat, 09 Dec 2006 07:31:30 GMT Creating a JAR File The basic format of the command for creating a JAR file is: jar cf jar-file input-file(s) The options and arguments used in this command are: The c option indicates that you want to create a JAR file. The f option indicates that you want the output to go to a file rather than to stdout. jar-file is the name that you want the resulting JAR file to have. You can use any filename for a JAR file... http://JAVA.e-articles.info/title/How-to-create-view-extract-and-update-a-JAR-file-archive/ http://JAVA.e-articles.info/title/How-to-create-view-extract-and-update-a-JAR-file-archive/ Wed, 06 Dec 2006 08:39:35 GMT The basic format of the command for creating a JAR file is: jar cf jar-file input-file(s) The options and arguments used in this command are: The c option indicates that you want to create a JAR file. The f option indicates that you want the output to go to a file rather than to stdout. jar-file is the name that you want the resulting JAR file to have. You can use any filename for a JAR file... http://JAVA.e-articles.info/title/How-to-create-a-JAR-File/ http://JAVA.e-articles.info/title/How-to-create-a-JAR-File/ Thu, 23 Nov 2006 09:47:40 GMT This section explains how to use the PATH and CLASSPATH environment variables on Microsoft Windows, Solaris, and Linux. Consult the installation instructions included with your installation of the Java Development Kit (JDK) software bundle for current information. After installing the software, in the JDK directory, the bin directory contains both the compiler and the launcher. Update the PATH Variable (Microsoft Windows NT/2000/XP) You can run Java applications just fine without setting the PATH variable... http://JAVA.e-articles.info/title/How-to-use-the-PATH-and-CLASSPATH-environment-variables-on-Windows-Solaris-and-Linux/ http://JAVA.e-articles.info/title/How-to-use-the-PATH-and-CLASSPATH-environment-variables-on-Windows-Solaris-and-Linux/ Wed, 22 Nov 2006 10:55:45 GMT To create a Java program with a graphical user interface (GUI), you'll want to learn about Swing. The Swing toolkit includes a rich set of components for building GUIs and adding interactivity to Java applications. Swing includes all the components you would expect from a modern toolkit: table controls, list controls, tree controls, buttons, and labels. Swing is far from a simple component toolkit, however... http://JAVA.e-articles.info/title/What-Is-Swing/ http://JAVA.e-articles.info/title/What-Is-Swing/ Fri, 08 Dec 2006 11:23:50 GMT Objects are key to understanding object-oriented technology. Look around right now and you'll find many examples of real-world objects: your dog, your desk, your television set, your bicycle. Real-world objects share two characteristics: They all have state and behavior. Dogs have state (name, color, breed, hungry) and behavior (barking, fetching, wagging tail)... http://JAVA.e-articles.info/title/What-Is-a-Java-Object-~-Advantages-of-bundling-code-into-individual-software-objects/ http://JAVA.e-articles.info/title/What-Is-a-Java-Object-~-Advantages-of-bundling-code-into-individual-software-objects/ Sat, 25 Nov 2006 12:31:55 GMT