Java for mobile app development: How to create Android apps in 2025

by Sarah Dunsby

Java has been a dominant and widely adopted programming language in mobile application development for many years. Even as new languages and frameworks emerge, Java remains a core technology, especially for Android development. In 2025, Java continues to be a reliable and well-supported option for mobile app developers, particularly those targeting the Android ecosystem. In this article, we explore why Java still matters, how to create an app using Java, and what tools and practices are relevant today.

The continued role of Java in Android development

Java and Android development have been closely connected since Android’s inception. Although Kotlin has become increasingly popular in recent years, Java remains officially supported and continues to be widely used. According to recent developer surveys, a significant number of Android apps are either fully built in Java or include substantial Java codebases.

As of 2025, Java continues to play an essential role within Android Studio, the official integrated development environment for Android. Developers who prefer Java benefit from strong documentation, backward compatibility, and a large community. Additionally, the Android SDK still offers extensive support for Java, making it a viable choice for both new apps and the maintenance of existing ones.

Why choose Java for mobile app development?

When evaluating a programming language for mobile app development, several important criteria are considered, such as performance, security, community support, and ease of learning. Java consistently performs well across all of these areas.

Its mature ecosystem is one of its greatest strengths, offering a long history of development supported by a wide range of tools and established best practices.

While Java is primarily known for its role in Android development, it also supports cross-platform development through frameworks like Codename One and J2ObjC, making it more versatile than often assumed.

In terms of security, Java offers robust built-in protections, including sandboxing and bytecode verification, which help safeguard applications from common threats.

Java also offers excellent scalability, making it a strong fit for both simple mobile apps and large-scale, enterprise-grade solutions. These combined advantages position Java as a strong and reliable choice for startups and large organizations.

Fundamental principles of mobile app development with Java

Before starting the development process, it’s important to grasp the underlying architecture of an Android application. Android apps built with Java generally consist of the following core components:

• Activities: Represent screens with which users interact.
• Services: Handle background processing.
• Broadcast Receivers: Handle and react to broadcast messages sent across the system.
• Content Providers: Facilitate access to and management of shared data across different applications.

Understanding these components helps developers organize their code and ensure their apps function smoothly across different Android devices.

How to create an app using Java in 2025

Although tools and technologies have advanced, the fundamental process of developing an Android app with Java has remained mostly unchanged. Here are the key steps involved:

1. Set up the development environment

Android Studio is the go-to IDE for Java and Android development. It includes all the necessary tools for developing, testing, and deploying mobile applications. Setting it up involves installing the Java Development Kit (JDK) and the Android SDK, which are essential components of the development environment. Java 17 or newer is recommended, as Android supports modern Java features.

2. Design the user interface

Android apps use XML for designing UI layouts. Java then connects the XML layouts to backend logic using activity or fragment classes. This division of responsibilities results in more organized code and simplifies the debugging process.

3. Implement app logic

With the UI in place, developers can write Java code to handle user input, manage app states, and integrate APIs. Thanks to its object-oriented design, Java simplifies maintaining and scaling the application’s logic.

Typical tasks include fetching and displaying data from local databases or remote servers, managing app state and navigation between screens, and handling background tasks like downloading files or syncing data.

4. Test your application

Testing plays a vital role in the mobile app development process. Android Studio supports unit testing, UI testing, and integration testing, all of which can be written in Java. Tools like Espresso and JUnit help ensure code reliability.

Android Studio enables developers to easily execute and debug tests right within the integrated development environment. You can also integrate testing into a Continuous Integration (CI) pipeline to automate this step during development.

5. Deploy and maintain

Once the app is tested, it can be packaged and deployed via the Google Play Store.

1. Use Android Studio to generate a signed APK or Android App Bundle (AAB).
2. Set up a developer account on the Google Play Console.
3. Upload your app, include details like description and screenshots, and set pricing or availability.
4. Submit your app for review, and once it’s approved, it will be available on the Play Store.

Continued maintenance, such as updates and bug fixes, can be handled within the same Java codebase.

Best practices for developing mobile apps with Java

In 2025, best practices for Java mobile app development have evolved to include a range of modern methodologies and tools that improve maintainability and overall code quality.

One important approach is the use of modular architecture, with patterns like MVVM (Model-View-ViewModel) helping developers structure code in a more organized and scalable way.

Dependency management has also become more streamlined through the use of libraries such as Dagger and Hilt, which simplify and automate the process of injecting dependencies throughout an application.

To ensure responsive performance, developers now rely heavily on asynchronous programming techniques, utilizing APIs like ExecutorService as well as more modern reactive libraries.

Version control remains essential for team collaboration, with Git continuing to serve as the standard tool for tracking changes and managing codebases.

Furthermore, implementing continuous integration and continuous deployment (CI/CD) pipelines has become a common practice, enabling automated testing and quicker release of updates. Together, these practices support the creation of more stable, maintainable, and high-performing mobile applications.

Java vs. Kotlin: Which to choose in 2025?

Although Kotlin has become the preferred language for many Android developers, Java continues to be favored for several key reasons:

• Legacy Codebases: Many large apps are still written in Java and require ongoing support.
• Interoperability: Kotlin and Java work seamlessly together, allowing them to be used side by side within a single project.
• Learning Curve: Java is often easier to learn for those new to programming.

Choosing between Kotlin and Java depends on the project requirements and the team’s familiarity with the language. However, Java continues to be a solid and dependable choice for mobile app development.

Tools and libraries supporting Java in 2025

Several modern tools and libraries boost the development experience when using Java for mobile apps:

• Room: A persistence library for local data storage.
• Retrofit: For handling API calls and network operations.
• Glide: For image loading and caching.
• Firebase: Offers cloud-based services like real-time databases and analytics.
• Crashlytics: Helps monitor app crashes in real time.

These tools are all compatible with Java and help accelerate the development process while improving app performance and reliability.

Java software outsourcing: Scaling mobile projects

While the process of developing an Android app may seem easy on the surface — especially with that many tools and online tutorials — the reality is far more complex. Building a stable and scalable mobile app requires consistent coding practices, testing, and ongoing updates. Many in-house teams may lack the experience or capacity to handle this entire lifecycle, which is why outsourcing becomes a strategic choice.

Many companies turn to outsourcing to scale their development efforts. Working with a specializedjava software outsourcing company can provide access to skilled developers, reduce time to market, and cut down on costs. These companies often have deep expertise in Java mobile app development and can assist in everything from initial planning to long-term maintenance.

Outsourcing is beneficial for startups looking to bring an MVP to market quickly, enterprises that need to maintain legacy systems, or businesses that require specialized skills or domain expertise.

Future outlook for Java and Android development

As Android continues to evolve, so too does the ecosystem around Java. In 2025, Java remains a cornerstone of Android development, bolstered by strong community support and ongoing updates. The language has seen performance improvements and syntactical enhancements that make development faster and more intuitive.

Mobile apps are increasingly enhanced by advancements in machine learning, IoT integration, and edge computing. Java is well-positioned to support these trends, particularly due to its stability and libraries.

Conclusion

Java continues to thrive as a leading option for mobile app development. Its seamless compatibility with the Android SDK makes it a practical choice in 2025. Regardless of whether you’re а beginner or a seasoned developer, Java provides the necessary tools to create impressive applications.

However, building a competitive mobile app today often demands more than internal resources can support. From evolving platform requirements to continuous maintenance, mobile development has grown increasingly complex. Collaborating with an outsourcing company allows businesses to tap into specialized expertise and speed up time to market.

FAQs: Java for mobile app development in 2025 Is Java still a good choice for Android development in 2025?

Yes. Even with Kotlin’s growing popularity, Java continues to be a stable and officially supported language for Android development, extensively utilized in both legacy systems and new projects.

What are the primary advantages of using Java for developing mobile applications?

Java offers a mature ecosystem, strong security, and cross-platform potential. It supports scalable architecture and works well for small MVPs and enterprise applications. Its object-oriented structure also makes it suitable for modular and maintainable codebases.

Is it possible to develop cross-platform mobile apps using Java?

While Java is most commonly used for Android, there are frameworks such as Codename One and J2ObjC that allow partial cross-platform development using Java. However, for full cross-platform solutions, other tools like Flutter or React Native are typically used in conjunction with platform-specific languages.

How much time does it take to develop an Android app with Java?

The timeline depends on the app’s complexity, team size, and development process. Developing a simple MVP could take a week or two, whereas building a comprehensive enterprise-level app may require more time.

Is outsourcing Java development a viable option for startups?

Yes. Outsourcing allows startups to create dependable mobile applications without the need to assemble a complete in-house development team. Experienced outsourcing partners can also assist with long-term support.

Will Java continue to be relevant for mobile apps in the future?

Yes. Java has shown long-term resilience and adaptability. With continuous updates and wide usage in Android development, Java is expected to remain relevant for mobile app development well beyond 2025.