I am starting a new series called Java Coding Quiz, in which I'll show you subtle Java concepts hidden in the code. This is an OCAJP or OCPJP style question but focused on teaching subtle details of Java programming language. In today's puzzle, you will learn about one of the key concepts about how floating point and integer arithmetic works in Java. This is a very important concept for any Java developer because Java behaves differently when the same operation is performed by different types of variable but of the same value.
Spring and Hibernate are two of the hottest and most in-demand web frameworks in Java world and also two of the most essential skill for any Java programmer to get a Job in web development space. The Spring framework is in around from 2004 and established itself as the leading framework to develop Java applications both in core Java and web development area. The Spring framework comes with a lot of modules to support a different kind of developments e.g Spring Security to address the security requirements of most web and enterprise Java applications. It supports single sign-on, LDAP authentication, Role-based access control, and much more such essential features. Spring also supports the development of REST services which is no become standard way to provide web services.
Java 5 added Executor Framework to provide out-of-box thread pool to Java programmers and Java 7 added ForkJoinPool an implementation of ExecutorService which specifically designed to execute ForkJoinTask. The Executor Framework provides several classes e.g. Executor, ExecutorService, and Executors for execution and creating thread pools. It also provides several built-in, ready to use thread pools like a pool of fixed threads, cached thread pool which can expand itself, spawn new threads if required due to heavy load.