15 Important Java Developer Skills (And How To Improve)

Updated 17 March 2023

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Software developers consider Java as a foundational coding language, and they use it to develop web-based applications and software for multiple platforms. Though Java is a basic programming language, professionals may learn specific skills to become advanced programmers. Along with coding skills, you may need technical abilities and soft skills to work to your full potential. In this article, we examine the top 15 Java developer skills that can help you become successful in this job role.

What does a Java developer do?

A Java developer is a programmer who works with other programmers, software developers and software engineers to integrate Java programming with websites, applications and other business software. A Java developer also takes responsibility for other duties, including designing and testing during the app or software development cycle. They may:

work with team members to design, roll out and maintain each of the Java application development phases
participate in developing the software architecture
transform client requirements into stipulations or guidelines
conduct testing, debugging and software analysis
understand all issues and risks related to production and roll-out
maintain application software
work out changes and recommend them to stakeholders
be in touch with clients after release to help with any unexpected problems

Top 15 Java developer skills

Since Java developers are involved in multiple activities other than coding, they have to equip themselves with many relevant skill sets. Though basic Java is easy to pick up, they may acquire intermediate and advanced Java coding skills to advance their career. These are some important skills for Java developers:

1. Java systems

Sun Microsystems released Java in 1995, and they update their system every few years. In recent times, new rollouts happen once every six months. It is not easy to know about every update, and hence, it is generally advised that Java developers understand Java systems from Java 8 iteration onwards. Java developers benefit from familiarising themselves with the latest revisions, to stay updated.

2. Core Java skills

Java developers require a basic understanding of core concepts like:

Object-Oriented Programming: OOP, as it is known, is a programming model that organises software around data and objects instead of logic. This basic Java skill combines objects and enhances the security and stability of a code.
Design patterns: These are programs that help find a solution to frequently occurring problems during coding. Java developers need to familiarise themselves with the three categories of design patterns.
Abstract classes: Abstraction is used in OOP to simplify coding. Developers use a Java interface for advanced coding.
Serialisation: It is a mechanism in Java where one object is represented as a sequence of bytes. The Java process does the serialisation that transports objects between Java virtual machines.

3. Java build tools

Java developers use Java build tools to automate source code applications. They can choose from a range of tools that help them complete their projects efficiently. A few examples of Java build tools include Apache, Sonatype, Gradle, Bazel, Nexus and Cmake.

4. Java EE components

Java EE (Enterprise Edition) has many components. A Java developer requires a good understanding of how to compose server-side applications using EE components. Some of the important components are Java Beans, Java Server Pages and Servlets.

5. Java testing tools

Apart from coding, Java developers may be part of the testing processes too. Testing tools allow developers to test their code through a separate database without using a web browser to launch the application. Tools like TestNG and Selenium allow Java developers to test multiple processes easily.

6. Big data

Developers prefer Java as it is one of the best languages to learn Big Data. Hadoop and HDFS are written in Java. Developers have used Java in building many ETL applications like Apache Kafka and Apache Camel, which are useful for data extraction and loading. Good knowledge of Java helps in working with Big Data.

7. Application containers

Developers use application containers as components required in a software program. JBoss and Jetty application containers are popular among developers. They cover many functions, from logging into a database to authenticating a user.

8. SOLID principles

These are principles of object-oriented programming that aim to improve quality as well as maintenance processes. SOLID includes:

Single responsibility: Developers make a class responsible for just one item to avoid interconnected problems within a program.
Open-closed: Functions, classes and modules remain open for extensions but not for modifications.
Liskov substitution: This principle advises developers that subclasses should replace related superclasses.
Interface segregation: Developers should create interfaces specific to one client to avoid irrelevant interfaces in a program design.
Dependency inversion: Java developers create dependency objects as abstractions instead of specific items. Another aspect of this principle states that high-level modules do not depend on low-level modules.

9. Spring framework

Spring framework is a simplified process and has superior capabilities for object injection. Many developers prefer using it to build Java applications. Developers can use the Spring framework at all levels of software development.

10. Android/Kotlin

Java is a popular language to develop mobile applications. It is beneficial for developers to learn Kotlin, a revised Java language which is currently considered an industry standard to develop mobile apps. Kotlin is interoperable with Java, and hence learning Kotlin will be a value addition for developers.

11. DevOps tool

Software developers apply DevOps processes like continuous integration and deployment to their app development process. Hence, Java developers benefit from updating their skills and learning DevOps tools. Some of the important DevOps tools are Jenkins, Kubernetes, Docker, Chef and Maven.

12. Blockchain

Developers prefer to use Java to develop blockchain. This technology helps developers create systems that are more secure and can prevent invasive attempts. A blockchain makes a note of all digital transactions on a computer network. Knowing about blockchain helps developers make use of opportunities that lie in this domain.

13. Soft skills

Apart from technical skills, developers may focus on developing soft skills that are crucial to their work. They work with a team from the concept development stage, all the way till the software is rolled out. Soft skills allow professionals to step up for tasks that may not be part of their prescribed responsibility.

14. Time management

A Java developer works under deadlines and a well-defined time frame for every phase of the application development cycle. They assess how much time is required to fulfil each phase from the start of the development process. They ensure that they complete all required phases on time, as per the client's requirements.

15. Communication skills

Java developers constantly communicate with their team members. They talk to clients and other stakeholders. They prepare manuals and documentation during various stages of a project. Hence, strong written and verbal communication skills are key for a Java developer.

What are Java full stack developer skills?

A full-stack developer works on both the server-side and client-side of an application. So, they can perform both front-end and back-end tasks related to Java software development. Since their work is all-inclusive, their skill set is also wide. Full-stack developers may be skilled in front end technology like HTML5 and CSS3 and may know multiple programming languages like Java, Ruby, Python and .Net.

Full-stack developers are experts at handling servers like Apache or Nginx and Version Control Systems like Git. They may require knowledge in database and cache technology as well as UI/UX design principles. They may also have experience with web services or API creations, REST and SOAP. They may be required to write unit tests and have good knowledge of algorithms, syntax and data structures.

How can I improve my Java skills?

Since the parent company revises Java continuously and periodically, it is important that developers also improve their Java skills to stay updated. Getting trained in the latest system, attending training programmes and getting certified in Java's latest components are common ways for improving Java skills. Constantly reading code, practising data structure and algorithms and using online resources like videos and training material are other ways to improve Java skills.

What can I do with Java skills?

If you are a Java developer who is up-to-date with the current system, you can build mobile applications and work with big data. WIth good Java skills, you can explore opportunities to work on cloud-based applications and develop artificial intelligence. You can participate in open source communities and be a part of many open source projects. Space programmes, automobile innovations, new-age technologies and applications are written in Java, and you can aspire to be part of these projects.

What makes a good Java developer?

A good Java developer is both skilled in coding and has good knowledge of Java's ecosystem. Some of the technologies associated with Java are constantly updated. A good Java developer has to be aware of the latest developments and revisions of Java. A Java developer who is a team player and problem-solver is a great asset to a software development team.

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