Add Java 14 support by replacing the final field access

pom.xml

@@ -12,7 +12,7 @@
     <name>Tamablefoxes</name>
 
     <properties>
-        <java.version>1.8</java.version>
+        <java.version>1.14</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     </properties>
 
@@ -24,8 +24,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.7.0</version>
                 <configuration>
-                    <source>${java.version}</source>
+                    <source>9</source>
-                    <target>${java.version}</target>
+                    <target>9</target>
                 </configuration>
             </plugin>
             <plugin>

src/main/java/net/seanomik/tamablefoxes/versions/FieldHelper.java

@@ -0,0 +1,34 @@
+package net.seanomik.tamablefoxes.versions;
+
+import java.lang.invoke.MethodHandles;
+import java.lang.invoke.VarHandle;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+public final class FieldHelper {
+
+    private static final VarHandle MODIFIERS;
+
+    static {
+        try {
+            MethodHandles.Lookup lookup = MethodHandles.privateLookupIn(Field.class, MethodHandles.lookup());
+            MODIFIERS = lookup.findVarHandle(Field.class, "modifiers", int.class);
+        } catch (IllegalAccessException | NoSuchFieldException ex) {
+            throw new RuntimeException(ex);
+        }
+    }
+
+    public static void makeNonFinal(Field field) {
+        int mods = field.getModifiers();
+        if (Modifier.isFinal(mods)) {
+            MODIFIERS.set(field, mods & ~Modifier.FINAL);
+        }
+    }
+
+    public static void setField(Field field, Object obj, Object value) throws IllegalAccessException {
+        makeNonFinal(field);
+        field.setAccessible(true);
+        field.set(obj, value);
+        field.setAccessible(false);
+    }
+}

src/main/java/net/seanomik/tamablefoxes/versions/version_1_14_R1/NMSInterface_1_14_R1.java

@@ -4,6 +4,7 @@ import net.minecraft.server.v1_14_R1.EntityFox;
 import net.minecraft.server.v1_14_R1.EntityTypes;
 import net.seanomik.tamablefoxes.Utils;
 import net.seanomik.tamablefoxes.io.LanguageConfig;
+import net.seanomik.tamablefoxes.versions.FieldHelper;
 import net.seanomik.tamablefoxes.versions.NMSInterface;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
@@ -19,20 +20,7 @@ public class NMSInterface_1_14_R1 implements NMSInterface {
     public void registerCustomFoxEntity() {
         try { // Replace the fox entity
             Field field = EntityTypes.FOX.getClass().getDeclaredField("aZ");
-            field.setAccessible(true);
+            FieldHelper.setField(field, EntityTypes.FOX, (EntityTypes.b<EntityFox>) EntityTamableFox::new);
-
-            // If the field is final, then make it non final
-            if ((field.getModifiers() & Modifier.FINAL) == Modifier.FINAL) {
-                Field fieldMutable = field.getClass().getDeclaredField("modifiers");
-                fieldMutable.setAccessible(true);
-                fieldMutable.set(field, fieldMutable.getInt(field) & ~Modifier.FINAL);
-                fieldMutable.setAccessible(false);
-            }
-
-            field.set(EntityTypes.FOX, (EntityTypes.b<EntityFox>) (type, world) -> new EntityTamableFox(type, world));
-
-            field.setAccessible(false);
-
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.GREEN + LanguageConfig.getSuccessReplaced());
         } catch (Exception e) {
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.RED + LanguageConfig.getFailureReplace());

src/main/java/net/seanomik/tamablefoxes/versions/version_1_15_R1/NMSInterface_1_15_R1.java

@@ -2,9 +2,9 @@ package net.seanomik.tamablefoxes.versions.version_1_15_R1;
 
 import net.minecraft.server.v1_15_R1.EntityFox;
 import net.minecraft.server.v1_15_R1.EntityTypes;
-import net.seanomik.tamablefoxes.TamableFoxes;
 import net.seanomik.tamablefoxes.Utils;
 import net.seanomik.tamablefoxes.io.LanguageConfig;
+import net.seanomik.tamablefoxes.versions.FieldHelper;
 import net.seanomik.tamablefoxes.versions.NMSInterface;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
@@ -20,20 +20,7 @@ public class NMSInterface_1_15_R1 implements NMSInterface {
     public void registerCustomFoxEntity() {
         try { // Replace the fox entity
             Field field = EntityTypes.FOX.getClass().getDeclaredField("ba");
-            field.setAccessible(true);
+            FieldHelper.setField(field, EntityTypes.FOX, (EntityTypes.b<EntityFox>) EntityTamableFox::new);
-
-            // If the field is final, then make it non final
-            if ((field.getModifiers() & Modifier.FINAL) == Modifier.FINAL) {
-                Field fieldMutable = field.getClass().getDeclaredField("modifiers");
-                fieldMutable.setAccessible(true);
-                fieldMutable.set(field, fieldMutable.getInt(field) & ~Modifier.FINAL);
-                fieldMutable.setAccessible(false);
-            }
-
-            field.set(EntityTypes.FOX, (EntityTypes.b<EntityFox>) (type, world) -> new EntityTamableFox(type, world));
-
-            field.setAccessible(false);
-
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.GREEN + LanguageConfig.getSuccessReplaced());
         } catch (Exception e) {
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.RED + LanguageConfig.getFailureReplace());

src/main/java/net/seanomik/tamablefoxes/versions/version_1_16_R1/NMSInterface_1_16_R1.java

@@ -2,9 +2,9 @@ package net.seanomik.tamablefoxes.versions.version_1_16_R1;
 
 import net.minecraft.server.v1_16_R1.EntityTypes;
 import net.minecraft.server.v1_16_R1.EntityFox;
-import net.seanomik.tamablefoxes.TamableFoxes;
 import net.seanomik.tamablefoxes.Utils;
 import net.seanomik.tamablefoxes.io.LanguageConfig;
+import net.seanomik.tamablefoxes.versions.FieldHelper;
 import net.seanomik.tamablefoxes.versions.NMSInterface;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
@@ -21,20 +21,7 @@ public class NMSInterface_1_16_R1 implements NMSInterface {
     public void registerCustomFoxEntity() {
         try { // Replace the fox entity
             Field field = EntityTypes.FOX.getClass().getDeclaredField("be");
-            field.setAccessible(true);
+            FieldHelper.setField(field, EntityTypes.FOX, (EntityTypes.b<EntityFox>) EntityTamableFox::new);
-
-            // If the field is final, then make it non final
-            if ((field.getModifiers() & Modifier.FINAL) == Modifier.FINAL) {
-                Field fieldMutable = field.getClass().getDeclaredField("modifiers");
-                fieldMutable.setAccessible(true);
-                fieldMutable.set(field, fieldMutable.getInt(field) & ~Modifier.FINAL);
-                fieldMutable.setAccessible(false);
-            }
-
-            field.set(EntityTypes.FOX, (EntityTypes.b<EntityFox>) (type, world) -> new EntityTamableFox(type, world));
-
-            field.setAccessible(false);
-
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.GREEN + LanguageConfig.getSuccessReplaced());
         } catch (Exception e) {
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.RED + LanguageConfig.getFailureReplace());

src/main/java/net/seanomik/tamablefoxes/versions/version_1_16_R2/NMSInterface_1_16_R2.java

@@ -4,6 +4,7 @@ import net.minecraft.server.v1_16_R2.EntityFox;
 import net.minecraft.server.v1_16_R2.EntityTypes;
 import net.seanomik.tamablefoxes.Utils;
 import net.seanomik.tamablefoxes.io.LanguageConfig;
+import net.seanomik.tamablefoxes.versions.FieldHelper;
 import net.seanomik.tamablefoxes.versions.NMSInterface;
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
@@ -12,7 +13,6 @@ import org.bukkit.craftbukkit.v1_16_R2.entity.CraftEntity;
 import org.bukkit.entity.EntityType;
 
 import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
 
 public class NMSInterface_1_16_R2 implements NMSInterface {
 
@@ -20,20 +20,7 @@ public class NMSInterface_1_16_R2 implements NMSInterface {
     public void registerCustomFoxEntity() {
         try { // Replace the fox entity
             Field field = EntityTypes.FOX.getClass().getDeclaredField("bf");
-            field.setAccessible(true);
+            FieldHelper.setField(field, EntityTypes.FOX, (EntityTypes.b<EntityFox>) EntityTamableFox::new);
-
-            // If the field is final, then make it non final
-            if ((field.getModifiers() & Modifier.FINAL) == Modifier.FINAL) {
-                Field fieldMutable = field.getClass().getDeclaredField("modifiers");
-                fieldMutable.setAccessible(true);
-                fieldMutable.set(field, fieldMutable.getInt(field) & ~Modifier.FINAL);
-                fieldMutable.setAccessible(false);
-            }
-
-            field.set(EntityTypes.FOX, (EntityTypes.b<EntityFox>) (type, world) -> new EntityTamableFox(type, world));
-
-            field.setAccessible(false);
-
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.GREEN + LanguageConfig.getSuccessReplaced());
         } catch (Exception e) {
             Bukkit.getServer().getConsoleSender().sendMessage(Utils.getPrefix() + ChatColor.RED + LanguageConfig.getFailureReplace());