logback-classic 1.3.5的build-jdk-spec含义及JDK8兼容问题咨询

Hey there! Let's unpack what's going on here, step by step.

What does build-jdk-spec: 19 mean? #

That entry in the logback-classic 1.3.5 Manifest file tells you two key things:

• When the Logback team built this version of the library, they used JDK 19's API specification as their target.
• This doesn't mean you have to run your app on JDK 19, but it does mean the code was compiled using features, classes, or methods that are part of JDK 19's standard library—many of which aren't available in older JDK versions like 8.

Why are you seeing UnsupportedOperationException on JDK 8? #

The short answer: Logback 1.3.x dropped support for JDK 8 entirely.

The 1.2.x branch of Logback is the last one designed to work with JDK 8. Starting with 1.3.x, the library requires a minimum JDK version of 11 (and in this case, compiled against JDK 19's specs, which is even further ahead). When you try to run code compiled for JDK 19 on JDK 8, you'll hit missing APIs or incompatible method signatures—hence the UnsupportedOperationException you're seeing.

How to fix this issue #

You have two straightforward options:

• Stick with JDK 8: Downgrade your Logback dependency to the latest version in the 1.2.x branch (currently 1.2.12 is the final stable release for JDK 8 compatibility).
• Upgrade your JDK: If your project can support it, upgrade to JDK 11 or higher (JDK 17 or 19 are great LTS options). This will let you use Logback 1.3.5 without compatibility issues, plus you'll get all the security and performance improvements from newer JDK versions.

内容的提问来源于stack exchange，提问作者Saurabh Kulkarni