Java was introduced in 1995 and it remains one of the most popular programming languages despite competition from new programming languages. Java is widely used to build cross-platform Android and web applications. Cloud systems, machine learning environments and Internet of Things are also widely built using Java.
Technology companies regularly Hire Java Programmer because Java is very much in demand. 40% of the developers all over the world use Java. However, companies look for Java programmers who are not only well versed in core or basic Java skills but are also conversant with the latest developments. Some of the essential skill sets to get hired as a Java programmer have been discussed here.
Core Java Skills
Core Java Skills which companies looking to Hire Java Programmers are object-oriented, design patterns, abstract classes and serialization.
Object-Oriented Programming or OOP is a class and object style of coding which encompasses various concepts such as inheritance, encapsulation, abstraction, polymorphism, operations, pre-defined types and user-defined types. OOP enhances the stability and security of the code by binding the data and functions. The Java programmer should understand the five principles of object-oriented programming which are as follows.
- The single responsibility principle states that a single class should be responsible for only one thing. In case, a single class is responsible for solving several problems, its subsystems for solving those problems are connected.
- Open-Closed principle states that classes, functions and modules can be open for extension only and cannot be modified.
- Liskov substitution principle states that subclasses should replace their superclasses.
- The interface segregation principle states that each interface should be created for a specific client.
- Dependency inversion principle states that higher-level modules should not depend on lower-level modules and abstractions should be independent of details.
Design patterns are templates that are used to solve design problems that crop up during software development. A design pattern can be customized to rectify any design problem in code for seamless software development.
Abstract classes enhance the code readability by showing only the necessary details of the object. Abstraction is an essential component of object-oriented programming to reduce code complexity. For example, Java Interface is an advanced abstraction class to provide efficient abstraction in Java.
Serialisation enables the Java programmer to transport Java objects from one Java virtual machine to another by converting the Java objects into a byte stream and reversing them into original objects after completing the transportation process.
Microservices
Java programmers should know how to develop Microservice applications because such applications are in demand. To this end, Java programmers must be well versed with Docker Container. This is because Docker Container is used for creating and compiling Microservice applications in various environments.
As regards to Microservices Software Development architecture, the Java programmer must be conversant with authentication, authorisation, data security, network security and deployment. There is numerous microservices pattern that the programmer needs to learn. These include GraphQL APIs, HTTPS for security, Access and Identity Tokens, RSocket Endpoints, Scan Docker and Kubernetes Configuration, Docker Rootless Mode, best practices for Cloud and Cluster specific security, time-based security, handling sensitive information and delivery pipeline.
Build tools
A Java programmer should know how to use Java Build Tools. Java Build Tools such as Maven and Gradle are programs that automatically create executable applications from source codes. The programmer needs to use a specific build tool for a particular task as per the nature of the task.
APIs
Java programmers should learn several APIs such as XML processing APIs, JSON processing APIs, Collection APIs, Logging APIs and Date, and Time APIs. Java Libraries for XML processing APIs are Stax and JAXB. JSON processing APIs which should be learned by Java programmers include JSON-io, Jackson, Genson and Gson. JSON-p package comes in standard Java libraries. There are many Java Collection APIs to learn such as PriorityQue, HashSet, LinkedHashSet, ArrayList, LinkedList, ArrayDeque, Vector and Stack.
Open Source Big Data Tools
To land a job as a big data developer, a Java programmer can learn to process huge datasets. There are a few open sources big data tools which can be used with Apache for huge datasets. These include Hadoop, Spark, Storm and Mahout. Other tools such as Cassandra, RapidMiner and MongoDB can also be learned. Java is all set to become a big deal in the world of big data.
JVM Internals
Java programmer should have sufficient knowledge of JVM Internals. There are numerous topics associated with JVM Internals such as JVM options, JIT, collector, CPU and RAM connections, concurrency handling, race conditions, execution models, garbage collectors and bottlenecks in performance. The concepts of Java byte code and how JVM executes the code in various operating systems such as Windows, Mac and UNIX should be learned. Proper understanding of Java code runtime errors and compiler errors is also important.
Web Frameworks
Knowledge of Java Web Frameworks is a useful advantage for Java programmers. This is because Java Web Frameworks have web services, web resources and web APIs which help in building and deploying web applications on the World Wide Web. Java Web Frameworks also enable developers to build mobile applications studded with features but using limited code. Spring MVC and Play are considered to be the best Java Web Frameworks.
Machine Learning
Machine Learning is the future and it has already been implemented in many applications such as automatic cars, customer service, fraud detection, etc. Thus, it is highly useful for Java programmers to learn machine learning algorithms using Java. There are many machine learning libraries and tools for Java programmers. These include Java-ML, Weka, Apache Spark, Mahout and Deeplearning4j.
IDE Tools
A Java programmer should be well versed with Integrated Development Environment Tools such as Intelli J and Eclipse. Intelli J has a syntax tree that is project-specific and uses indexing for analysing projects. It has to search and autocomplete features. Various versions of control systems are supported by a single interface. Eclipse provides support for different project structures. It has a workspace to manage numerous projects in a single window. It has a framework that adds and creates plugins. Support is also provided for 1276 plugins. Intelli J is suitable for small projects while Eclipse is well suited for large and complex projects.
Cloud environments
Organizations are increasingly moving to cloud platforms. As per research conducted in 2018, 90% of the organizations would eventually migrate to cloud. Thus, it is professionally useful for Java programmers to acquire the skills to develop cloud-based applications. Most of the organizations, 88% as per a survey, are using Amazon Web Services cloud platform. Thus, AWS is a suitable platform to learn. Other cloud platforms such as Microsoft Azure and Google Cloud Platform can also be learned.
Java EE and Spring Framework
Java Enterprise Edition provides libraries, APIs, tools and services to build large-scale server-side applications. Java EE is also suitable for managing web-based clients because it provides JavaServer Pages and Servlet APIs which enable logging using cookies. Apart from Java EE, Spring Framework is also popular among companies because it is open source which reduces the costs of license. A Java programmer should learn both Java EE and Spring Framework.
