Upgrade to Java 17: The Power pack Upgrade to Java Development

Gaurav Rajapurkar - A Technology Enthusiast

10 min readSep 30, 2023

Hi All ,

Today, We will go through an Overview of Upgrading Java 8 /Java 11 to Java 17 and the benefits it brings to Application Developers.

Let’s Get Started .

Java 17 Upgrade: Why and How

Technology is changing faster than ever, and Java is no exception. With the release of Java 21 . JDK 21 reached General Availability on 19 September 2023. it’s time to start thinking about upgrading your applications.

JDK 21

This release is the Reference Implementation of version 21 of the Java SE Platform, as specified by JSR 396 in the Java…

openjdk.org

If we are at Java 17 then it’s easier for your company to upgrade to Java 21 and so on.

Here are a few reasons why you should consider the upgrade to Java 17:

Improved performance: Java 17 includes a number of performance enhancements, such as improved garbage collection algorithms and a new JIT compiler.
New language features: Java 17 introduces a number of new language features, such as sealed classes and records. These features can make your code more concise, readable, and maintainable.
Security updates: Java 17 includes a number of security updates, such as support for new TLS versions and improved certificate validation.
Better tool support: Java 17 includes improved support for popular development tools, such as Eclipse and IntelliJ IDEA.

If you’re still using an older version of Java, don’t worry. There are two easy ways to upgrade:

Migrate directly from Java 8 to Java 17: This is the quickest and easiest way to upgrade, but it’s important to test your code thoroughly to make sure that it still works correctly with Java 17.
Migrate from Java 8 to Java 11 and then to Java 17: This approach is a bit more involved, but it can be helpful if you have any compatibility issues with Java 17.

No matter which approach you choose, upgrading to Java 17 is a good way to improve the performance, security, and maintainability of your applications.

Java 17 was released on September 14, 2021. It is an important long-term support (LTS) release in the Java development cycle, meaning it will receive updates and support for an extended period, making it a reliable choice for many Java applications.

Upgrading to Java 17 can indeed bring significant benefits in terms of modern Java development. Java 17 was released in September 2021 as a long-term support (LTS) version, which means it will receive updates and support for a longer period. Here are some of the key features and improvements in Java 17:

Sealed Classes: Sealed classes allow you to restrict which other classes or interfaces can extend or implement them. This can help you enforce better encapsulation and control over your class hierarchies.
Pattern Matching for instanceof: Pattern matching simplifies and streamlines conditional code. It can make your code more concise and readable, especially in situations where you need to check and cast objects.
Records: Records are a new type of class introduced in Java 16 that make it easier to create simple, immutable data objects. They automatically generate constructors, accessor methods, and other standard methods, reducing boilerplate code.
New Garbage Collectors: Java 17 includes two new garbage collectors, Z Garbage Collector and Shenandoah Garbage Collector. These collectors are designed to improve application responsiveness and reduce pause times.
Strong Encapsulation of Internal APIs: Java has been working on encapsulating internal APIs to make the platform more modular and maintainable. With Java 17, there are further restrictions on accessing internal APIs, which might require you to refactor your code.
Foreign Function & Memory API (Incubator): This is an incubator feature that allows you to interact with native code and memory more easily and safely. It can be beneficial for tasks like interoperation with C libraries.
Deprecation of Legacy Features: Java 17 continues the deprecation of older and less-used features, which means you might need to update your code to use more modern alternatives.
Performance Improvements: Every new Java version typically includes various performance enhancements, which can lead to faster execution of your applications.
Project Loom (Incubator): While not fully released in Java 17, Project Loom introduces lightweight, user-mode threads called fibers. This can be a game-changer for building highly concurrent and efficient applications.
Security Enhancements: Java updates often include security fixes and improvements. Upgrading to Java 17 ensures that you have the latest security patches.

Before upgrading to Java 17, it’s essential to consider the following steps at high level:

Review Your Codebase: Check your existing code for any deprecated or removed features that may require updates.
Testing: Thoroughly test your application with Java 17 to identify any compatibility issues or performance improvements.
Dependencies: Ensure that your third-party libraries and frameworks are compatible with Java 17.
Migration Plan: Develop a migration plan that outlines the steps to upgrade, including any necessary code changes and testing.
Performance Profiling: Use profiling tools to analyze the performance of your application with Java 17 and identify areas for optimization.
Backup: Make sure to have a backup of your project before the upgrade, so you can revert if any critical issues arise.

Upgrading to Java 17 can provide your application with the latest features, better performance, and long-term support. However, it’s crucial to plan and execute the upgrade carefully to minimize potential disruptions and ensure a smooth transition to the new version.

When upgrading from Java 8 or Java 11 to Java 17, it’s important to be aware of features and APIs that may have been deprecated, removed, or had their behavior altered. While Java strives to maintain backward compatibility, certain elements have evolved over time. Here are some changes and features from Java 8 and Java 11 that might not be supported or behave differently in Java 17:

Java 8 Features:

JavaFX: JavaFX, which was bundled with Java 8, is no longer included with Java starting from Java 11. You need to manage JavaFX separately if your application relies on it.
Nashorn JavaScript Engine: The Nashorn JavaScript engine, introduced in Java 8, has been deprecated and removed starting from Java 11. If you were using Nashorn, you’ll need to find an alternative JavaScript engine.

Java 11 Features:

Applets: Support for Applets was deprecated in Java 9 and removed in Java 11. If your application relies on Java Applets, you will need to rework it to use alternative technologies.
JEP 321: HTTP Client (Incubator): The HTTP Client API introduced as an incubator feature in Java 9 has been standardized in Java 11. Ensure that your code using the HTTP Client is compatible with the standard API.
JEP 330: Launch Single-File Source-Code Programs: If you were using the single-file source-code execution feature introduced in Java 11 (e.g., running Java programs without explicitly compiling them), it remains available in Java 17.
JEP 333: Z Garbage Collector: The Z Garbage Collector, which was introduced as an experimental feature in Java 11, has been enhanced and stabilized in subsequent releases, including Java 17.
JEP 335: Deprecate the RMI Activation System: If your code relies on the RMI Activation System, be aware that it has been deprecated starting from Java 11.
JEP 336: Deprecate the Pack200 Tools and API: The Pack200 tools and API were deprecated in Java 11. Ensure your application does not rely on them.
JEP 340: One AArch64 Port, Not Two: If you’re working on AArch64 platforms, be aware that Java 11 resolved the split between two AArch64 ports, and this continues in Java 17.
JEP 341: Default CDS Archives: Class Data Sharing (CDS) improvements introduced in Java 11 continue to evolve in Java 17.
JEP 343: Packaging Tool (jpackage): The jpackage tool introduced in Java 11 for packaging self-contained Java applications remains available in Java 17.
JEP 345: NUMA-Aware Memory Allocation: NUMA-aware memory allocation enhancements introduced in Java 11 continue to be supported and refined.

It’s essential to thoroughly review your codebase and dependencies when migrating from Java 8 or Java 11 to Java 17. Check for any deprecated APIs, features, or libraries that might have changed or been removed. Update your code accordingly and test rigorously to ensure compatibility and functionality with the newer Java version.

Migrating from Java 8 or Java 11 to Java 17 involves several steps to ensure a smooth transition. Here’s a step-by-step guide to help you migrate your Java application:

1. Review Release Notes:

Before starting the migration, review the release notes for Java 17 to understand the new features, changes, and any potential compatibility issues.

2. Update Development Environment:

Install Java 17 on your development machine. You can download it from the official Oracle website or use a distribution like OpenJDK.

3. Assess Compatibility:

Use tools like the Java Migration Assistant or the javac compiler with appropriate flags to identify any deprecated or removed features in your codebase.

4. Code Refactoring:

Modify your code to address any issues identified in step 3. This may involve:
Replacing deprecated APIs with their modern equivalents.
Updating libraries and dependencies to versions compatible with Java 17.
Addressing changes in API behavior or functionality.
Adjusting code that relies on internal APIs that are no longer accessible.

5. Build and Test:

Rebuild your application with Java 17 to ensure that it compiles without errors.
Conduct thorough testing, including unit tests, integration tests, and functional tests, to verify that your application functions correctly.

6. Performance Profiling:

Use performance profiling tools to analyze the performance of your application on Java 17. Identify any performance bottlenecks or areas for optimization.

7. Third-Party Dependencies:

Ensure that all third-party libraries and frameworks used in your application are compatible with Java 17. Update them if necessary.

8. Update Build Tools:

If you use build tools like Maven or Gradle, update your build configuration to specify Java 17 as the target runtime.

9. IDE Updates:

If you use an Integrated Development Environment (IDE) like IntelliJ IDEA or Eclipse, ensure that it is configured to use Java 17 for your project.

10. Continuous Integration/Deployment (CI/CD): — Update your CI/CD pipelines to use Java 17 for building and testing your application.

11. Documentation: — Update your project documentation to reflect the new Java version requirements.

12. Rollout Plan: — Plan a phased rollout of your application with Java 17 to minimize potential disruptions for users.

13. Monitor and Optimize: — After the migration is complete, continue to monitor your application’s performance and behavior on Java 17. Optimize as needed to take advantage of new features and improvements.

14. Backup: — Ensure that you have a backup of your project before migrating, so you can revert if any critical issues arise.

15. Retain Compatibility: — If you have clients or users still on older Java versions (e.g., Java 8), consider maintaining compatibility or providing migration guidance for them.

16.Communicate with stakeholders: It is important to communicate with stakeholders throughout the upgrade process. This includes keeping stakeholders informed of the progress of the upgrade, as well as any potential risks or delays.

Migrating to a newer Java version like Java 17 can offer numerous benefits, including improved performance, access to new features, and long-term support. However, thorough planning, testing, and careful consideration of your application’s specific requirements are essential to ensure a successful migration without disruptions.

Upgrading Java applications can be a daunting task, but it is an important one. By following the tips above, you can plan and execute a successful upgrade that will improve the performance, security, and maintainability of your applications.

In summary, upgrading to Java 17 is a must for any developer looking to stay current with the latest trends in software development and take advantage of the latest features and improvements offered by the Java platform. So, if you haven’t already made the switch, now is the time to upgrade to Java 17 and experience the benefits of modern Java development.

We hope you liked this post on an Overview of Upgrading Java 8 /Java 11 to Java 17 and the benefits it brings to Application Developers.

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