Why You Should Migrate from JDK 9 Before It's Too Late

Java Development Kit (JDK) is crucial for Java developers. However, the evolution of this toolkit means that older versions can quickly become obsolete. If you're still using JDK 9, it’s time to reconsider your options. In this blog post, we will discuss why you should migrate from JDK 9, the benefits of upgrading to a later version, and steps to make the transition smoother.

The State of JDK 9: A Quick Overview

Released in September 2017, JDK 9 introduced several exciting features, such as:

Java Platform Module System (JPMS): This functionality improved code encapsulation and modularization.
JShell: A Read-Eval-Print Loop (REPL) tool that bolstered rapid Java development.
Improved performance: Enhancements to the Java runtime improved overall performance.

The Downside of Staying with JDK 9

Despite these advantages, staying with JDK 9 comes with several significant drawbacks. The Java community is continuously evolving, and so are development practices. Here are some compelling reasons to migrate now.

End of Public Updates: JDK 9 reached its end of updates in March 2018. This means no more standard support or security patches are available. Running legacy software is akin to inviting security vulnerabilities into your applications.
Incompatibility Issues: New libraries, frameworks, and tools are less likely to support older versions. This incompatibility can prevent you from leveraging new features or bug fixes.
Community Support: Community engagement usually shifts toward newer versions. If you encounter bugs or issues, you may find it difficult to source help or information.

Benefits of Migrating to a Later Version

Here are key benefits to consider when contemplating an upgrade.

Long-Term Support (LTS)

Versions like JDK 11 and JDK 17 are Long-Term Support releases. They receive critical updates, security patches, and bug fixes for several years.

Robust Security Features: JDK 11 introduced various security improvements, including better TLS and enhanced cryptography.
Ongoing Performance Improvements: Each iteration sees enhancements in garbage collection, memory management, and speed.

New Features and Improvements

Upgrading unlocks a host of new features. Let's explore some worthwhile additions in JDK 11 and JDK 17.

Local-Variable Syntax for Lambda Parameters (JDK 11): This feature allows you to use var in lambda expressions, making your code cleaner.
```
// Before JDK 11
(String s) -> s.length();

// With JDK 11
(var s) -> s.length();
```

Pattern Matching for instanceof (JDK 16): This feature streamlines type checks in Java.

// Before
if (obj instanceof String) {
    String s = (String) obj;
}

// With JDK 16
if (obj instanceof String s) {
    // Use s directly, no need for casting
}

For deeper insights into new Java features, you might consult the Java documentation.

Agile Development

Keeping your tools updated means the ability to incorporate best practices and newer methodologies more seamlessly into your development processes. Features such as Project Loom promise to simplify concurrent programming, thereby enhancing productivity.

Steps for a Smooth Migration

Migrating from JDK 9 to a newer version can seem daunting. However, breaking it down into manageable steps can help.

Step 1: Audit Your Current Applications

Start by identifying applications running on JDK 9. Document their dependencies and libraries, and check their compatibility with JDK versions 11 and 17.

Step 2: Test Your Codebase

Create a workspace to test your existing codebase with a newer JDK version:

Use unit tests to ensure that functionality remains intact.
Check for deprecations or incompatible APIs.

Step 3: Update Dependencies

Updating your application often means updating libraries and frameworks as well. Use a build tool like Maven or Gradle to manage your dependencies automatically.

In Maven, you can easily update the version in the pom.xml:

<dependency>
    <groupId>org.example</groupId>
    <artifactId>my-library</artifactId>
    <version>1.2.0</version>
</dependency>

Step 4: Execute a Staged Rollout

If feasible, run your updated application in a staging environment before moving to production. This strategy minimizes risk and helps catch unforeseen issues.

Step 5: Continuous Monitoring

Once deployed, keep an eye on your application. Monitor performance metrics and error rates. This vigilance provides insight into areas where optimization might be necessary.

Remember to Consider Future Upgrades

Migrating to a new version of JDK is not the end of the journey. The Java community is growing, and new features will continuously emerge. For example, Project Panama aims to improve native access, while Project Valhalla focuses on enhancing the Java language itself.

Whenever a new version is released, evaluate the features and community support before committing to it. Staying ahead of the curve ensures that you reap the benefits of Java's ongoing evolution.

The Closing Argument

If you're still operating on JDK 9, the risks of staying outdated significantly outweigh the comfort of familiarity. Security vulnerabilities, lack of support, and missed opportunities for improvement are just a few reasons to consider migration. Emphasizing on best practices will ensure a smooth transition to a more resilient application structure.

Don't postpone your migration; act now. The benefits of using a newer JDK version are numerous, and the transition becomes even simpler with thorough planning. Embrace the latest advancements in the Java ecosystem and future-proof your applications today.

For detailed migration guides, you can visit Oracle's official migration documentation.

Remember, Java is constantly evolving. Don't let your projects become obsolete—upgrade today!