JavaBeat

1) Introduction Regular Expressions are basically patterns of characters which are used to perform certain useful operations on the given input. The operations include finding particular text, replacing the text with some other text, or validating the given text. For example, we can use Regular Expression to check whether the user input is valid for [...]

The Rounding Mode Enum in java.math package is used to perform precise rounding of decimal values. It was introduced in Java 5.0. This Enum provides various constants each of which is used for different modes of rounding. The decimal value would be rounded off to the number of decimal places based on the scale that [...]

Prototype pattern is one of the creational patterns that concentrate on duplicating objects if needed. Assuming that we are in process of creating a template. Most of the times, we copy an existing template, do some changes in it and then will use it. Technically, we make a copy of the source, make some changes [...]

The Java Mail API provides support for sending and receiving electronic mail messages. The API provides a plug-in architecture where vendor’s implementation for their own proprietary protocols can be dynamically discovered and used at the run time. Sun provides a reference implementation and its supports the following protocols namely, Internet Mail Access Protocol (IMAP) Simple [...]

Arguments and properties can be passed to a java application from command line. In this techical tip, let us see how to pass arguments as well as properties from command line. Passing arguments from command line The syntax to pass arguments from command line is as follows, 1 2   java <classname> <argument1> <argument2> <argument3> [...]

Random numbers in java can be generated either by using the Random class in java.util package or by using the random() method in the Math class in java.lang package. In both these approaches, we only get a pseudo random number and not a true random number because it is all generated based on some mathematical [...]

Let us write a Simple Downloader in this techincal tip by making use of the classes with java.net package. URL stands for Uniform Resource Locator and it is used to locate a resource in the Web in a standard fashion. A resource in the Web can be anything; it can be as simple as Html [...]

Though Java provides an extensive set of in-built exceptions, there are cases in which we may need to define our own exceptions in order to handle the various application specific errors that we might encounter. While defining an user defined exception, we need to take care of the following aspects: The user defined exception class [...]

In this technical tip, let us see an easy way of achieving file copy using File Channels. File Channels are part of Java New I/O Packages. A file can be viewed as a sequence of bytes. The various Buffer classes in New I/O Packages serve as a container for manipulating the primitive byte contents. It [...]