feat(bukkit/paper): Update RegistryReflection for Minecraft 1.21

closes #78

Author: jpenilla

cloud-bukkit/src/main/java/org/incendo/cloud/bukkit/internal/CraftBukkitReflection.java

@@ -24,8 +24,10 @@
 package org.incendo.cloud.bukkit.internal;
 
 import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.function.Supplier;
 import java.util.stream.Stream;
@@ -203,6 +205,14 @@ public final class CraftBukkitReflection {
         }
     }
 
+    public static @Nullable Constructor<?> findConstructor(final @NonNull Class<?> holder, final @NonNull Class<?>... parameters) {
+        try {
+            return holder.getDeclaredConstructor(parameters);
+        } catch (final NoSuchMethodException ex) {
+            return null;
+        }
+    }
+
     public static boolean classExists(final @NonNull String className) {
         return findClass(className) != null;
     }
@@ -235,6 +245,20 @@ public static Stream<Method> streamMethods(final @NonNull Class<?> clazz) {
         return Arrays.stream(clazz.getDeclaredMethods());
     }
 
+    public static Object invokeConstructorOrStaticMethod(
+        final Executable executable,
+        final Object... args
+    ) throws ReflectiveOperationException {
+        if (executable instanceof Constructor<?>) {
+            return ((Constructor<?>) executable).newInstance(args);
+        } else {
+            if (!Modifier.isStatic(executable.getModifiers())) {
+                throw new IllegalArgumentException("Method " + executable + " is not static.");
+            }
+            return ((Method) executable).invoke(null, args);
+        }
+    }
+
     private CraftBukkitReflection() {
     }
 }

cloud-bukkit/src/main/java/org/incendo/cloud/bukkit/internal/RegistryReflection.java

@@ -24,7 +24,7 @@
 package org.incendo.cloud.bukkit.internal;
 
 import io.leangen.geantyref.GenericTypeReflector;
-import java.lang.reflect.Constructor;
+import java.lang.reflect.Executable;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
@@ -51,10 +51,7 @@ public final class RegistryReflection {
             "net.minecraft.resources.MinecraftKey",
             "net.minecraft.resources.ResourceLocation"
     );
-    private static final Constructor<?> RESOURCE_LOCATION_CTR = CraftBukkitReflection.needConstructor(
-            RESOURCE_LOCATION_CLASS,
-            String.class
-    );
+    private static final Executable NEW_RESOURCE_LOCATION;
 
     private RegistryReflection() {
     }
@@ -65,6 +62,7 @@ private RegistryReflection() {
             REGISTRY_REGISTRY = null;
             REGISTRY_GET = null;
             REGISTRY_KEY = null;
+            NEW_RESOURCE_LOCATION = null;
         } else {
             registryClass = CraftBukkitReflection.firstNonNullOrThrow(
                     () -> "Registry",
@@ -90,6 +88,13 @@ private RegistryReflection() {
                     .filter(m -> m.getParameterCount() == 0 && m.getReturnType().equals(resourceKeyClass))
                     .findFirst()
                     .orElse(null);
+
+            NEW_RESOURCE_LOCATION = CraftBukkitReflection.firstNonNullOrThrow(
+                () -> "Could not find ResourceLocation#parse(String) or ResourceLocation#<init>(String)",
+                CraftBukkitReflection.findConstructor(RESOURCE_LOCATION_CLASS, String.class), // <= 1.20.6
+                CraftBukkitReflection.findMethod(RESOURCE_LOCATION_CLASS, "parse", String.class), // 1.21+
+                CraftBukkitReflection.findMethod(RESOURCE_LOCATION_CLASS, "a", String.class)
+            );
         }
     }
 
@@ -122,7 +127,7 @@ public static Object registryByName(final String name) {
 
     public static Object createResourceLocation(final String str) {
         try {
-            return RESOURCE_LOCATION_CTR.newInstance(str);
+            return CraftBukkitReflection.invokeConstructorOrStaticMethod(NEW_RESOURCE_LOCATION, str);
         } catch (final ReflectiveOperationException e) {
             throw new RuntimeException(e);
         }