Java Development for iOS Applications

Mobile app development typically falls into three categories: Android, iOS, and cross-platform technologies. The third option, cross-platform development, has evolved into a field of its own, as developers aim to bridge the gap between Android and iOS. A common question is whether Java, traditionally used for Android, can also be effectively used for iOS app development.

The answer to this cross-platform challenge is more nuanced than it seems. There are various approaches to this issue, each with its own pros and cons, depending on the specific project and team requirements.

In this post, we’ll explore whether Java development for iOS is a viable solution for your team and how you can leverage it to build high-performance apps that reach a wider audience.

Mobile iOS App Development Today

The first step to understating iOS apps is understanding where the mobile app platform currently sits today.

Traditionally, native iOS app development has focused on Objective-C development—a language originally developed in the 1980s to implement object-oriented features on C-like code. More recently, Swift has become the default language for building ioS and macOS applications due to its modernized approach and design.

Similarly, Java was adopted as the initial language of native Android development until giving way to modernized Kotlin code in more recent years.

While cross-platform frameworks have long provided developers with ways to reduce the code necessary to target both platforms, early attempts introduced performance issues, design challenges, and often integration disasters. For as long as there have been smartphone applications, however, there’s been a desire for a native development tool capable of targeting each of the major platforms with a single codebase.

Some key reasons developers may want to use Java to target iOS devices include:

• Having an existing Android app to port to iOS. Developers and companies might have a highly successful Android solution that could prove successful in the iOS app store. Currently, using both platforms’ native languages doubles development, testing, and deployment efforts
• Java developers would appreciate an additional platform to broaden their opportunities for producing apps
• Companies with significant investment in Java tools and skills would similarly appreciate being able to target iOS Without additional investment in new developers, tools, and resources

So far, outside of cross-platform frameworks and niche tools, the opportunity to write native code that works on both Android and iOS has been very limited. Developers tend to have to compromise between extended testing and troubleshooting to iron out issues or extended development time in rewritingrewriting code from the ground up.

Yet, even within the field of mobile development, Java has a major role to play as a key technology for developers.

To help understand the Java development skills in high demand today, we’ve prepared an expert article that takes a deep dive into thethe skills and technologies your teams should know.

Reasons for Developers to Learn Java

Android Development

Google recommends Kotlin for new projects, but Java has been the dominant development language for the platform since its initial release. For Android mobile development, being able to maintain legacy apps and lean on Java libraries for future development is a significant advantage for teams.

Legacy Big-data tools

While modern data analysis is increasingly moving to Python and related languages, many tools such as Spark, Hadoop, and neo4j have a grounding in Java—making the language a useful one to know.

Approachable to Beginners

Java is widely regarded as an excellent language for learning software development and getting started with big projects. While few development teams are going to be starting newcomers with complex software engineering projects on day 1, the approachable nature of the language makes it easier to onboard junior developers from other disciplines in a short amount of time.

Versatility and Flexibility

A language that was designed from the ground up to be able to run anywhere, Java has maintained a lot of its versatility as it’s grown through the years. Today, Java is used to target a broad spectrum of apps and services from desktop applications to cloud computing resources.

Drawbacks of Java

Overhead

The JVM (Java Virtual Machine) introduces significant overhead in both resource use and the complexity of integrating code with other systems. For embedded systems and lightweight hardware, this completely rules out the language for use.

Compatibility Issues

Differences in implementation and use that have crept in between Oracle’s Java implementation and open Java platforms have caused issues in many codebases. These issues can extend beyond the technical into licensing problems too

Few Good UI tools

Java has never been a language known for promoting exceptional design and user experience. There are still few exceptionally capable frameworks for creating attractive, functional, and ground-breaking user interfaces for Java applications. For mobile apps, this can be a significant drawback as UI is often a make-or-break feature for users.

Java Development for iOS Today

For developers then, there are several reasons to jump into learning Java to develop apps. When it comes to approaching iOS development with Java there are just a handful of capable, productive, and reliable tools we can lean on to build great software. These include:

Translation to Objective-C

The simplest way for developers to convert a Java mobile application to run natively on iOS is to simply translate the code into Objective-C. This allows for an existing Android or desktop app to be converted to its equivalent iOS app with a suite of automated tools.

While this won’t run a Java app on the iOS platform, it’s a strong option for developers with an existing piece of software that they’d like to port to the Apple app store.

j2objc is a tool still in a beta stage of development but has also seen widespread use and a great deal of appreciation from its community.

Platform Independent Java Code

Over the past decade, there have been significant efforts from the OpenJDK mobile community to port the Java Development Kit to all major mobile platforms. This project already supports Android’s use of both Java and Kotlin with significant progress being made in extending this platform to iOS and Windows mobile devices in recent years.

When it comes to iOS development, there are options available to build and maintain the JDK on iOS devices to support natively produced Java applications. While far from straightforward in comparison to conventional iOS development, restricted in implementation, and requiring some workarounds to fully function—this approach to running Java code in the iOS environment can make an ideal testing suite or suit some limited production use cases.

To help build the teams that can write Java applications for your business, we’ve compiled a complete guide to working with remote Java Developers to avoid the pitfalls and traps that often come with the field.

Java Mobile Framework

The most well-supported approach to Java development for iOS is inevitably going to be a framework that allows developers to target the platform as one of several app environments.

Since the launch of the app store in 2008, frameworks targeting multiple mobile platforms have been a key part of development. These are often grounded in JavaScript or a similar accessible language that can later be compiled to Objective-C, Java, or something else.

One of the leading options for cross-platform Java development comes from Codebase One. The framework allows developers to create truly native mobile applications for each of the major platforms while writing apps in Java. While this approach locks developers into the framework’s existing ecosystem, the broad opportunities it provides in unlocking mobile and desktop platforms may well be worth the trade-off.

We’ve prepared a guide to hiring, managing, and maintaining mobile application developers within your teams to help bring these technologiestechnologies into your organization.

iOS Java Development

There’s no doubt that Java development on iOS is a somewhat niche use of the language. While many developers have thought of and wished for the technology at one time or another, the tools and resources out there to support it are still exceptionally limited today.

Yet, if you have a compelling enough case to overcome the technical hurdles for your next project, it’s a goal that is entirely reachable. Using the Java cross-platform framework, JDK port, or a simple translation of Java code to Objective-C Java development for iOS apps is entirely possible.

Any of these three approaches can bring you Java application development on iOS to build novel, interesting, and exciting solutions within your teams.

FAQs

Q1. Is it possible to use Java with iOS?

Yes, it’s entirely possible to use Java with iOS to create mobile apps on the Apple platform. While using Java to target iOS is still a relatively niche use, it can be achieved with some technical work and planning.

Apps built using Java for the iOS platform should be thoroughly tested and managed well to limit issues arising from using the technologies in this way.

Three key ways you can use Java with iOS are:

• Using a Java to Objective-c translation tool. Able to take existing production code and convert it into an equivalent iOS app, this tool can be an excellent choice if you already have an application you want to port
• Porting the OpenJDK to iOS. A project that has been decades in the making, it’s possible to run the OpenJDK on the iOS platform and run Java code natively on the device
• Java Framework. A framework such as Codebase One can target iOS as one of its development platforms and create apps using Java

Q2. Can I Write Java code directly on my iPhone?

There are multiple ways for developers to write and run code directly on an iPhone today. While mobile devices are notably less powerful than desktop machines, there are plenty of reasons to want to try out a small piece of code or project solution on the go.

The easiest way to get started with programming on iOS is one of the available code editor apps available on the app store. Apps such as Koder and Textastic allow for code to be written and edited right there in the app. Both apps support remote connections and a suite of tools that can make connecting and running Java code while on the move a breeze.

Additionally, online IDEs are increasingly available and capable ways for developers to build and run applications. These can be accessed and shared anywhere from any kind of device and allow for programming in almost any language from an iPhone or iPad.