How to add JAR file in Eclipse Project Build path - External dependency

In this Java Eclipse tutorial, I will show you two ways to add external JAR files in Eclipse Java projects. Many times we need to use external JAR files in our Java application for different needs e.g. for general purpose you may use Google Guava or Apache Commons. If you are using Spring or Hibernate framework then you need their JAR files as well. In order to use any third-party library or framework, we have to add their JAR files in the classpath, to compile and run our Java programs. Since Eclipse is the most popular IDE for developing Java applications, it's important to know how you can add external JARs into your Java project's build path. For example, suppose, you have downloaded Apache commons JAR file from the internet and wants to add that file to your Java project. In order to use classes and methods from that library, your project must reference those and this is what we will learn here.

Top 10 OCAJP and OCPJP Exam Simulators for Java Certifications

There is no doubt that exam simulators play an important role in preparing for any Java certification e.g. OCAJP, OCPJP, OCEJWCD,   OCMJEA exams. In fact, they are one of the most important pillars because choosing a good exam simulator with a good book is generally the success mantra of many Java certification aspirants. The exam simulators prepare you well for exams by presenting the the level of questions you can expect in real exams. They provide the must needed practice in exam like environment to gauge your speed and accuracy. I have personally seen difference of 30% in score between people who do a lot of mock exams and who just goes without practicing mock exams. Candidates makes more mistakes when they first took exams and by participating in mock tests, you train your mind to do less mistakes. They also help you to better handle the time pressure of real exam.

2 Best Books to Learn Hibernate for Java Developers

Hibernate is the leading ORM (Object to relational) framework in Java world used to implement persistence layer of enterprise Java applications. It was one of the first Java frameworks on ORM persistence and exists even before the Java Persistence API was introduced. It has since then implement JPA interfaces and you can use Hibernate as one of the JPA implementation. In fact, it is one of the most popular JPA implementation in Java world. I receive a lot of email about books and tutorial to learn Hibernate, especially from intermediate Java developers, who has a couple of years of experience in Java but new to Hibernate. It is also a very useful skill to have on your resume because they are a lot of companies who are using Spring and Hibernate to developer enterprise Java application. So if you are looking for a job in Java world, particularly as Java web development role learning both Spring and Hibernate can help you to get your dream job.

12 Advanced Java programming books for Experienced developers - Part 2

This is the second part of 12 must read advance Java programming books for intermediate and experienced Java programmers. In the first part, I have shared books to learn and master concurrency, performance, design patterns, and Java collection framework. In this part, I will talk about more advanced concepts e.g. security, Java 8, best practices etc. As an experienced Java developer, a lot is expected from you. Junior developers look at you for guidance and project managers look at you to solve problems and bail them out at key junctures. If you don't have solid knowledge of the various aspect of software development, testing, deployment, and documentation, you won't be able to do your job properly and rise in your career.

Best way to Convert Integer to String in Java with Example

Integer to String conversion in Java
There are many ways to convert an Integer to String in Java e.g. by using Integer.toString(int) or by using String.valueOf(int), or by using new Integer(int).toString(), or by using String.format() method, or by using DecimalFormat, String concatenation, or by using StringBuilder and StringBuffer etc. Some of them we have already seen on my earlier posts e.g. how to convert int to String and converting double to String. Even though those posts gives you tricks to convert primitive int to String and primitive double to String, you can still use those tricks to convert a wrapper class object e.g. Integer or Double to String in Java. Both are good ways, but out of those which is the best way to convert an Integer to String in Java?  You will find out in this article.

Top 5 Reasons of Exception in thread "main" java.lang.NoClassDefFoundError in Java

NoClassDefFoundError in Java
The Exception in thread "main" java.lang.NoClassDefFoundError is a common error in Java which occurs if a ClassLoader is not able to find a particular class in the classpath while trying to load it. The Exception in thread "main" suggests that this error has occurred in the main thread, the thread which is responsible for running Java application. This error can occur to any thread but if it happens in main thread then your program will crash. As per Javadoc, NoClassDefFoundError can be thrown during linking or loading of the class file. It's denoted by java.lang.NoClassDefFoundError and comes when that particular class is present during compile time but somehow not available during runtime. This could be due to missing JAR file, any permission issue, or incorrect classpath on runtime, depending upon your environment.