Java Core

Create a Java project with Apache Maven


In this tutorial, we will learn how to create a Java project with Maven, imports it into the Eclipse IDE, and package the Java project into a jar file. Tools used : Maven 3.2.5 (For how to install, click here) Eclipse (Kepler Release) JDK 7 A. Create a Java Project from Maven Template In a terminal (*uix or Mac) or ... Read More »

Regular Expression in Java


Java provides the java.util.regex package for pattern matching with regular expressions. A regular expression is a special sequence of characters that helps you match or find other strings or sets of strings, using a specialized syntax held in a pattern. They can be used to search or edit or manipulate data. The java.util.regex package primarily consists of the following three ... Read More »

Getting System Out to Write to a Particular File on System


This tutorial redirects the System.out to a file provided by the user. Steps to follow – 1. Create a file myconsole.txt. 2. Create a PrintStream which uses FileOutputStream 3. Set the System Out with PrintStream object. package com.jkoder; import; import; import; import; public class RedirectSystemOutput { public static void main(String[] args) throws FileNotFoundException { System.out.println("This output ... Read More »

Direct Web Remoting

DWR is Open Source, available under the Apache Software License v2. DWR is a Java library that enables Java on the server and JavaScript in a browser to interact and call each other as simply as possible. DWR will generate the JavaScript to allow web browsers to securely call into Java code almost as if it was running locally. It ... Read More »

How to do Reverse DNS (rDNS) lookup in java


What is Reverse DNS Lookup Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address using the Domain Name System (DNS) of the Internet. Computer networks use the Domain Name System to determine the IP address associated with a domain name. This process is also known as ... Read More »

Executing Operating System/ Shell Commands In Java


In Java, you can execute external OS/shell commands. There are two ways to start an operating system process/execute shell command within Java: java.lang.Runtime#exec(java.lang.String), since Java 1 java.lang.ProcessBuilder, since Java 5 We will here show you both ways to execute Operating System/ Shell Commands 1. Using java.lang.Runtime The java.lang.Runtime class allows the application to interface with the environment in which the ... Read More »

How To Use HttpClient


This java based tutorial is designed to provide a basic overview of how to use HttpClient. Downloaded HttpClient and dependencies listed below that are required to put them on your classpath. httpclient-4.2.3.jar from> commons-codec.jar from commons-logging.jar from junit.jar from The general process for using HttpClient consists of a number of steps: Create an instance of HttpClient. ... Read More »

How To Set Fake User Agent


How to set fake user agent What is user agent? User agent is software agent that is acting on behalf of a user. For example, an email reader is a mail user agent, and in the Session Initiation Protocol (SIP), the term user agent refers to both end points of a communications session. User agent acts as a client in ... Read More »

How To Avoid Memory Leak in Java


How to avoid Memory leak issue in Java What is Memory Leak? Memory leak mainly occurs when a program does not release the memory it has obtained for temporary use, it is the condition where the available computer memory reduces gradually there by resulting in poor performance. How to determine if Memory Leak exists in a Java application? If the ... Read More »