Port AP to Java 17

annotation-processor/build.gradle

@@ -30,7 +30,7 @@ dependencies {
 }
 
 tasks.withType(JavaCompile) {
-    options.release = 21
+    options.release = 17
 }
 
 shadowJar {

annotation-processor/src/main/java/org/fury_phoenix/mixinAp/annotation/ClientMixinValidator.java

@@ -90,24 +90,19 @@ public class ClientMixinValidator {
     }
 
     private boolean targetsClient(Object classTarget) {
-        return switch (classTarget) {
-            case TypeElement te ->
-                isClientMarked(te);
-            case TypeMirror tm -> {
+        if (classTarget instanceof TypeElement te) {
+            return isClientMarked(te);
+        } else if (classTarget instanceof TypeMirror tm) {
             var el = types.asElement(tm);
-                yield el != null ? targetsClient(el) : warn("TypeMirror of " + tm);
-            }
-            // If you're using a dollar sign in class names you are insane
-            case String s -> {
-                var te =
-                elemUtils.getTypeElement(toSourceString(s.split("\\$")[0]));
-                yield te != null ? targetsClient(te) : warn(s);
-            }
-            default ->
+            return el != null ? targetsClient(el) : warn("TypeMirror of " + tm);
+        } else if (classTarget instanceof String s) {
+            var te = elemUtils.getTypeElement(toSourceString(s.split("\\$")[0]));
+            return te != null ? targetsClient(te) : warn(s);
+        } else {
             throw new IllegalArgumentException("Unhandled type: "
                 + classTarget.getClass() + "\n" + "Stringified contents: "
                 + classTarget.toString());
-        };
+        }
     }
 
     private boolean isClientMarked(TypeElement te) {

build.gradle.kts

@@ -91,12 +91,7 @@ tasks.named<Jar>("jar") {
     ))
 }
 
-// We must force the Java 21 compiler to be used because our AP requires Java 21
-
 java {
-    toolchain {
-        languageVersion = JavaLanguageVersion.of(21)
-    }
     val curSourceCompatLevel = JavaVersion.VERSION_17
     sourceCompatibility = curSourceCompatLevel
     targetCompatibility = curSourceCompatLevel