Sometime configuring Log4j using XML or properties file looks annoying, especially if your program not able to find them because of some classpath issues, wouldn't it be nice if you can configure and use Log4j without using any configuration file e.g. XML or properties. Well, Log4j people has thought about it and they provide a BasicConfigurator class to configure log4j programmatically, thought this is not as rich as there XML and properties file version is, but it's really handy for quickly incorporating Log4j in your Java program. One of the reason programmer prefer to use System.out.println() over Log4j, of-course for testing purpose, because it doesn't require any configuration, you can just use it, without bothering about XML or properties file configuration, but most programmer will agree that, they would prefer to use Log4j over println statements, even for test programs if it's easy to set them up. By the way, for production use prefer SLF4J over Log4J. In this Java tutorial, we will see a nice little tip to use Log4j right away by configuring in couple of lines. In fact you can configure Log4J in just one line, if you intend to use there basic configuration which set's the log level as DEBUG.
Thursday, December 12, 2013
Wednesday, December 4, 2013
Final keyword in Java is not as mysterious as volatile or transient, but still it creates lot of doubts on programmers mind. I often receives questions like, When to make a method final in Java or When to make a method static in Java, later I answered in my earlier post. Questions like this is not trivial, knowing what a keyword does is just small part of mastering that functionality. Similar to real world, where knowing that a sword can cut lot of things is not enough for a warrior to survive, you need to know how to use that and more importantly, use if effectively. Final keyword can be applied to class, methods and variable and has different meaning for each of them, but the motive remains same, it state completeness, it opposes change. For example, final class can not be extended, value of final variable can not be change and a final method can not be overridden in Java. This gives you first hint, when to make a method final in Java, obviously to prevent subclass for changing it's definition, technical preventing it from overridden. There are lot of clues on How to use final keyword on methods in Java API itself, one of the prime example of this java.lang.Object class, which declares a lot of method final including wait method with timeout. Another example of making a method final is template method, which outlines algorithm in Template method design pattern. Since, you don't want a sub class to change the outline of algorithm, making it final will prevent any accidental or malicious overriding. In this tutorial, we will learn few things, which will help you to effectively use final keywords with Java methods.
Friday, November 29, 2013
Java and Python are two of most popular and powerful programming language of present time. Beginner programmer often get confused, one of the most frequently asked question is should I learn Java or Python, Is Python is good programming language to start with, Which programming language would you recommend for beginners to learn first etc. Since I am a Java developer, my opinion is biased, I will always suggest you to start with Java and then learn Python, but if you ask this question to a Python developer, you might get just opposite answer. I have well documented my reasons as Why Java is best Programming language and Why a programmer should learn Java. One of the most important reason you would see on that blog post is strong Java community, which will help you though out your Java career. You can ask some beginner stuff starting from how to set PATH and classpath to advanced stuff about debugging Java program in Eclipse, no matter what kind of question is, there is always some one is Java community, who is ready to answer and help you. This is one of the reason that StackOverflow is full of Java questions. By the way Python is not spring chicken anymore, it has fully grown and giving strong competition to main stream language like Java and C++. When I first come across Python, I thought it's a scripting language, but that is an understatement. You can do object oriented programming in Python as well. On beginners point of view, I always suggest pick a language which is easier to learn, powerful to attract you and have strong community support, now both Java and Python fits this bill, and until you do some really good comparative analysis, you can not decide which language to learn from Java vs Python. Thankfully, we have an infographic, which highlights some important difference between Python and Java, I am sure after taking a look on this Infographic, you will be able to decide which is the right programming language to start with.