lower JDK version to 17

README.md

@@ -0,0 +1,39 @@
+# Bring Powersort to Java
+
+## Gradle
+
+### Setup
+
+Check which Java toolchains can be found by Gradle:
+
+```shell
+./gradlew javaToolchains
+```
+
+This should include version >= 17, e.g.:
+
+```
+ + N/A JDK 23-ga
+     | Location:           /nix/store/48290hnlb13xmwjw9y16a1s785993bv7-openjdk-23-ga/lib/openjdk
+     | Language Version:   23
+     | Vendor:             N/A
+     | Architecture:       amd64
+     | Is JDK:             true
+     | Detected by:        Current JVM
+```
+
+### Tasks
+
+List all tasks:
+
+```shell
+./gradlew tasks
+```
+
+## Test Cases
+
+Run the task "test":
+
+```shell
+./gradlew test
+```

app/build.gradle.kts

@@ -28,7 +28,7 @@ dependencies {
 // Apply a specific Java toolchain to ease working on different environments.
 java {
     toolchain {
-        languageVersion = JavaLanguageVersion.of(23)
+        languageVersion = JavaLanguageVersion.of(17)
     }
 }