May 25, 2020

What Does a Java Developer Do?

The king of cross-platform development, Java has a rich history and continues to be a mainstay in the development world.

Java is a programming language that continues to be in high demand, thanks in large part to its cross-platform support, established developer community and powerful features.

Java’s History

The Java language project was created in 1991 at Sun Microsystems, eventually being released as part of the Java platform in 1995, and making its official 1.0 appearance in 1996. Much of Java was eventually open sourced in 2007. In 2010, Oracle acquired Sun Microsystems and Java.

Java was built around the core principle of Write Once, Run Anywhere (WORA). In other words, the goal was to create a programming language that could support and run on virtually any platform from a single code base.

The key to Java’s approach was the Java Virtual Machine (JVM). The JVM is a virtual machine that takes the Java source code the programmer has written and translates it to Java bytecode, using it as an intermediate step. The average Java programmer, however, does not need to know bytecode, they simply need to program using the Java language.

Once the code is in Java bytecode, a Just In Time (JIT) compiler within the JVM converts the bytecode into native instructions, or machine code, for the target platform. Once translated to native code, the JIT compiler keeps it in memory for faster performance.

This process is why Java applications often take longer to start up than a fully native application. Once the translation has taken place and the native code is cached to memory, however, Java applications often provide speed on par with native apps.

Because a Java developer only has to worry about writing source code in the Java language, and letting the JVM do the rest, a developer can WORA—as long as their target platform has a viable JVM.

Language Features

Java shares much in common with C and C++. In fact, a programmer familiar with those two languages will recognize much within Java. At the same time, Java is generally not as low-level of a programming language as either of those two.

Another important differentiation is Java’s emphasis on object-oriented programming. While C is largely procedural and C++ can be either procedural or object-oriented, Java is primarily object-oriented.

One of the more challenging aspects for new programmers to master in many languages is recovering memory from objects that are no longer in use. As a result, the longer an app is running and the more tasks it performs, the more memory it continues to use. Everything it does leads to more and more objects being created, each one of them taking up memory. If a programmer does not properly manage this, the memory consumption can reach the point of crashing the application, or even the computer it’s running on.

In contrast, Java has automatic garbage collection. As objects stop being used, Java automatically recovers the memory from those unused objects. The only issue the programmer needs to worry about is not maintaining a link or reference to an object that is no longer in use. Doing so could still create a memory leak, as described above. Otherwise, the developer can simply let Java handle it.

Java is often cited as one of the most secure languages available. According to research, that claim is not without merit. WhiteSource did a study to determine which open-source languages had the most vulnerabilities.

C had the most, accounting for some 47%. This is not surprising, given that C is the oldest of the languages compared, and has endured more scrutiny than many of the others combined. Next was PHP with 17% of vulnerabilities. Java came in fifth with 12%, while JavaScript, Python, C++ and Ruby rounded out the top four with 11%, 6%, 6% and 5% percent of vulnerabilities respectively.

So while Java may not be the most secure language, it certainly is respectable.

The Type of Projects Java Developers Work On

With such a unique approach, especially its WORA philosophy, it’s little wonder that Java developers can work on a virtually infinite variety of projects.

Java is very popular for high-performance web applications. Twitter, Netflix and Priceline use Java to power their online services. Java is also very popular in the financial sector, with Barclays, Citigroup, Goldman Sachs and others relying on it for server-side applications. Many high-profile software development tools, such as Eclipse, IntelliJ Idea and NetBeans IDE, are written in Java as well.

Of course, one of the biggest markets for Java developers is Android apps. When Google released Android, they chose Java as the native language for creating Android software. As a result, while other languages have gained some traction, the most powerful Android apps are still written in Java and will continue to be.

It’s estimated there will be some 75 billion Internet of Things (IoT) devices by 2025. Given Java’s strengths, specifically its portability, it’s not surprising it is one of the top choices for IoT development.

Java Development: The Possibilities Are Endless

Given Java’s unique nature, widespread use and tangible benefits, it’s easy to see why the programming language not only endures, but continues to be a favorite among developers and corporations alike.

Learning Java, whether as a new or experienced developer, is an investment that will pay off in the long run. Check out the Java homepage to get started with the needed tools.

Tags Java
Matt Milano
Technical Writer
Matt is a tech journalist and writer with a background in web and software development.

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