Java Frameworks and tools Interview Questions

Java has been one of the most popular programming languages for years. Java has object-oriented features along with primitive data types. Java was originally developed by James Gosling at Sun Microsystems and released in 1995 and initially named as 'Oak'. It formed the core component of Sun Microsystems' Java platform. Java codes achieve platform independence by compiling its codes into bytecodes with the help of Java Virtual Machine (JVM). Java is widely used in Java is used in almost every kind of application like Mobile Applications, desktop applications, web applications, and many more. The most popular Android is based on Java.

Vaadin is a platform for web application development. It is an open-source platform widely used by developers. It is built on Google Web Toolkit (GWT) and uses JavaScript in the browser to communicate with various components on the server. The Vaadin Platform is made of

• a set of web components
• a Java web framework
• a set of tools and application starters.

The Vaadin Platform, previously Vaadin Framework, allows the developers to implement HTML5 web user interfaces along with Java Programming Language for the back-end. Vaadin provides numerous of out-of-the-box components. Other than that, Vaadin lets the developers create client-side widgets, which are compiled by the Vaadin Client Compiler to accommodate high customization.

Scala stands for Scalable language and is a combination of object-oriented and functional programming and thereby a high-level and multi-paradigm language. It was designed by Martin Odersky, professor at École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and was published in 2004. Scala's avoids bugs in various complex applications with the help of its static types. It does not support any type of primitive data and deals only with objects. Scala integrates with JVM and JavaScript runtimes which allow developers to build high-performance systems. Scala also gives easy access to huge ecosystems of libraries. The high scalability of Scala has attracted popular companies like Apple, Twitter, Walmart, and Google.

Maven is a build software project management and comprehension tool used primarily for Java projects but can be extended to manage projects in C#, Ruby, Scala, and many other languages. Maven was created by Jason van Zyl and came up as a subproject of Apache Turbine in 2002. The Maven project is now hosted by the Apache Software Foundation. It mainly highlights the two aspects of building software successfully-

• how software is built
• dependencies of the software.

Maven is based on a plugin-based architecture. Thus it can use any application controllable through standard input. Maven is also interoperable with a wide range of IDE.

Apache Groovy is a powerful object-oriented programming language for the Java platform. Groovy can act as both a programming language and a scripting language. It is smoothly interoperable with various Java code and libraries. Groovy has easy to learn syntaxes and focuses on improving the productivity of the developers The codes in groovy are compiled by Java Virtual Machine into bytecodes and hence are platform-independent. It acts as static as well as a dynamic language. Python, Ruby, and Smalltalk have deeply influenced the development of Groovy. Groovy also provides support for various markup languages like XML and HTML. Groovy 2.5.8 is the latest stable version available now.

Hibernate is a Java framework for simplifying the development of Java application to interact with the database. It is open-source software with ORM (Object Relational Mapping) tool. Hibernate is lightweight and implements the specifications of JPA (Java Persistence API) to keep data persistent. In Hibernate framework cache is internally used. This improves the performance of Hibernate by making it faster. Hibernate Query Language (HQL) used in Hibernate generates the database-independent queries and hence a change in the database does not alter query. Thus maintenance becomes easy with Hibernate.

Java Grails is an open-source web application framework written Apache Groovy programming language. It forms a consistent development framework for the developers. The convention-over-configuration, sensible defaults, and Groovy language together make Java Grails easy to learn and has become a high productivity framework. Java Grails smoothly interoperates with Java, the JVM, and existing Java EE containers. Java Grails is built on Spring Boot and hence is characterized by a time-saving feature. It also integrates GORM thus integrating implementations for Hibernate (SQL), MongoDB, Cassandra, and Neo4j. No XML configuration ready-to-use development environment, and functionality available through mixins differentiate Java Grills from traditional Java frameworks.

Apache Kafka is open-source stream-processing software that provides a unified platform for handling real-time data feeds. It is a high-throughput, low-latency software developed by LinkedIn and donated to the Apache Software Foundation. Apache Kafka is written in Scala and Java. Kafka connects to external systems for data import and export with the help of Kalfla Streams. Kafka also provides Kafka Streams as the stream processing library. Kafka is a favorite as it allows its users to publish to any number of systems and real-time applications. The most common example of the application of Apache Kafka is passenger management and driver matching in Uber cab service.

Gradle is an open-source build automation system that aims to increase the productivity of the developers. The concepts of Apache Ant and Apache Maven forms the base of Gradel. Unlike Apache Maven, Gradle does not use XML. Instead, it uses a Groovy-based domain-specific language. But it also supports many other programming languages. Gradle helps in the management of projects which are supposed to grow with time. Starting with mobile apps to big enterprises, Gradle assists in team building, automation and delivering the best software in the least time. Gradle has been noted for assisting 20 top open-source projects and has earned the trust of millions of developers.

Java Server Faces (JSF) is a Java-based web application framework that supports HTML5. It is popular among developers as it simplifies the development integration of web-based user interfaces. The Java Community Process has determined its specifications. Java Server Faces forms the standard display technology. JSF is based on the MVC framework and provides a very simple user interface for server-side applications and uses Facelets technology. JSF also encourages connecting user interface widgets with data sources. In JSF users can reuse and extend various user interface components. JSF also manages UI state across multiple server requests along with connecting client-side events to the server-side application code.

JSP (Java Server Pages) is a collection of technologies that are used to create dynamic, platform-independent methods for creating powerful web pages using MTML, SOAP, XML, and many more. JSP technology has many similarities with Servlets and ats an extension of the later. But JSP has lesser code length as compared to Servlets. Developers can easily embed java codes in HTML simply by introducing JSP tags. JSP shoes significantly high performance by allowing embedding dynamic elements in HTML pages. Moreover, JavaServer Pages form an integral part of Java EE. Thus JSP can become a unit in the simplest application of an extensive and complicated project.

Spring framework is an open-source Java platform which forms the inversion control container. Spring framework was initially developed by Rod Johnson and was released in June 2003. It provides comprehensive infrastructural support for building robust Java applications in minimum time. Spring has become one of the most popular enterprise Java owing to its high performance, easy testability, and reusability of codes. Spring is based on MVC architecture and can smoothly integrate with other existing frameworks like JEE, Quartz, JDK timers, and many more. Spring framework is also lightweight owing to its size and transparency. All these features together have made Spring a popular framework for Java developers.

Spring Boot is an open-source Java-based framework developed by Pivotal. It is widely used for developing scalable applications. It is used to create a micro Service and build stand-alone, production-ready spring applications. With the help of Micro Service Spring Boot allows the developers to develop and deploy services independent of each other. Spring Boot aims to reduce the development time considerably and run the applications built independently. It has gained popularity owing to its flexible way to configure Java Beans, Database Transactions, and XML configurations. The exclusive dependency management and auto-configuring capability of Spring Boot give the developers an added advantage.