10 Example of find command in Unix and Linux

The find command is one of the versatile commands in UNIX and Linux  and I used it a lot in my day to day work. I believe having good knowledge of find command in UNIX and understanding of its different options and usage will increase your productivity a lot in UNIX based operating system e.g. Redhat Linux or Solaris. If you are a QA, support personnel, and your works involve lots of searching text on Linux machine or if you are a Java or C++ programmer and your code resides in UNIX, find command can greatly help you to look for any word inside your source file in the absence of an IDE. It is the alternative way of searching things in UNIX, grep is another Linux command which provides similar functionality like find but in my opinion later is much more powerful than grep in UNIX.

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9 difference between Array vs ArrayList in Java

Both array and ArrayList are two important data structure in Java and frequently used in Java programs. Even though ArrayList is internally backed by an array, knowing the difference between an array and an ArrayList in Java is critical for becoming a good Java developer. If you know the similarity and differences, you can judiciously decide when to use an array over an AraryList or vice-versa. In this article, I'll help you understand the difference between ArrayList and array in Java. If you are coming from C or C++ background then you already know that array is one of the most useful data structure in the programming world. It offers O(1) performance for index-based search and one of the fundamental way to store data.

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How to declare and initialize a List (ArrayList and LinkedList) with values in Java

Initializing a list while declaring is very convenient for quick use, but unfortunately, Java doesn't provide any programming constructs e.g. collection literals, but there is a trick which allows you to declare and initialize a List at the same time. This trick is also known as initializing List with values. If you have been using Java programming language for quite some time then you must be familiar with syntax of array in Java and how to initialize an array in the same line while declaring it as shown below:

String[] oldValues = new String[] {"list" , "set" , "map"};

or even shorter :

String[] values = {"abc","bcd", "def"};

Similarly, we can also create List  and initialize it at the same line, popularly known as initializing List in one line example. Arrays.asList() is used for that purpose which returns a fixed size List backed by Array. By the way don’t confuse between Immutable or read only List which doesn’t allow any modification operation including set(index) which is permitted in fixed length List.Here is an example of creating and initializing List in one line:

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3 ways to loop over Set or HashSet in Java? Examples

Since Set interface or HashSet class doesn't provide a get() method to retrieve elements, the only way to take out elements from a Set is to iterate over it by using Iterator, or loop over Set using advanced for loop of Java 5. You can get the iterator by calling the iterator() method of Set interface. This method returns an iterator over the elements in the sets but they are returned in no particular order, as Set doesn't guarantee any order. Though individual Set implementations e.g. LinkedHashSet or TreeSet can impose ordering and in such iterator will return elements on that order. You can only traverse in one direction using iterator i.e. from first to last elements, there is no backward traversing allowed as was the case with List interface and ListIterator. Similarly, if you use advanced for loop, then also you can traverse in only one direction.

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Top 5 Hibernate Books for Java Developers - Best, Must read

Hibernate is one of the most popular, open source ORM (Object Relational Mapping) framework, which has now become a standard for developing persistence layer on Java enterprise application, along with JPA (Java Persistence API). I often receive  requests to suggest which book is best to learn to hibernate or recommendation about some good books on Spring and Hibernate. This motivates me to write this article about some of the best book on Hibernate, available in the market. Earlier I have shared some of the must-read books on Spring framework for Java developer, which is quite helpful for picking a book on Spring. Similar to Spring framework, experience in Hibernate is most sought after thing in Java JEE development roles.

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10 examples of grep command in UNIX and Linux

grep command is one of the most frequently used UNIX command stands for "Global Regular Expression Print" like find, chmod or tar command in Unix. grep command in Unix operating system e.g. Linux, Solaris, BSD, Ubuntu or IBM AIX is used to search files for matching patterns, by using grep command in Unix you can search a file which contains a particular word or particular pattern. UNIX grep command also provides several useful command line option which can be used to enhance the functionality of grep command e.g. by using grep -v you can list down all files which don't contain a word i.e. excluding files which matches a pattern, grep -c will print count of matching pattern in a file etc. One of the popular examples of grep command is to find empty files and directories in Unix.

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5 books to learn Spring framework and Spring MVC for Java Programmers

Spring and Spring MVC is one of the most popular Java frameworks and most of new Java projects uses Spring these days. Java programmer often asks questions like which books is good to learn Spring MVC or What is the best book to learn Spring framework etc. Actually, there are many books to learn Spring and Spring MVC but only certain books can be considered good because of  their content, examples or the way they explained concept involved in Spring framework. Similar to  Top 5 books on Java programming we will some good books on Spring in this article, which not only help beginners to start with Spring but also teaches some best practices.

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