SPIGOT-2540: Add nullability annotations to entire Bukkit API

By: Darkyenus <darkyenus@gmail.com>

paper-api/src/main/java/org/bukkit/configuration/serialization/ConfigurationSerializable.java

@@ -1,5 +1,7 @@
 package org.bukkit.configuration.serialization;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.util.Map;
 
 /**
@@ -31,5 +33,6 @@ public interface ConfigurationSerializable {
      *
      * @return Map containing the current state of this class
      */
+    @NotNull
     public Map<String, Object> serialize();
 }

paper-api/src/main/java/org/bukkit/configuration/serialization/ConfigurationSerialization.java

@@ -21,6 +21,8 @@ import org.bukkit.potion.PotionEffect;
 import org.bukkit.util.BoundingBox;
 import org.bukkit.util.BlockVector;
 import org.bukkit.util.Vector;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * Utility class for storing and retrieving classes for {@link Configuration}.
@@ -43,11 +45,12 @@ public class ConfigurationSerialization {
         registerClass(BoundingBox.class);
     }
 
-    protected ConfigurationSerialization(Class<? extends ConfigurationSerializable> clazz) {
+    protected ConfigurationSerialization(@NotNull Class<? extends ConfigurationSerializable> clazz) {
         this.clazz = clazz;
     }
 
-    protected Method getMethod(String name, boolean isStatic) {
+    @Nullable
+    protected Method getMethod(@NotNull String name, boolean isStatic) {
         try {
             Method method = clazz.getDeclaredMethod(name, Map.class);
 
@@ -66,6 +69,7 @@ public class ConfigurationSerialization {
         }
     }
 
+    @Nullable
     protected Constructor<? extends ConfigurationSerializable> getConstructor() {
         try {
             return clazz.getConstructor(Map.class);
@@ -76,7 +80,8 @@ public class ConfigurationSerialization {
         }
     }
 
-    protected ConfigurationSerializable deserializeViaMethod(Method method, Map<String, ?> args) {
+    @Nullable
+    protected ConfigurationSerializable deserializeViaMethod(@NotNull Method method, @NotNull Map<String, ?> args) {
         try {
             ConfigurationSerializable result = (ConfigurationSerializable) method.invoke(null, args);
 
@@ -95,7 +100,8 @@ public class ConfigurationSerialization {
         return null;
     }
 
-    protected ConfigurationSerializable deserializeViaCtor(Constructor<? extends ConfigurationSerializable> ctor, Map<String, ?> args) {
+    @Nullable
+    protected ConfigurationSerializable deserializeViaCtor(@NotNull Constructor<? extends ConfigurationSerializable> ctor, @NotNull Map<String, ?> args) {
         try {
             return ctor.newInstance(args);
         } catch (Throwable ex) {
@@ -108,7 +114,8 @@ public class ConfigurationSerialization {
         return null;
     }
 
-    public ConfigurationSerializable deserialize(Map<String, ?> args) {
+    @Nullable
+    public ConfigurationSerializable deserialize(@NotNull Map<String, ?> args) {
         Validate.notNull(args, "Args must not be null");
 
         ConfigurationSerializable result = null;
@@ -156,7 +163,8 @@ public class ConfigurationSerialization {
      * @param clazz Class to deserialize into
      * @return New instance of the specified class
      */
-    public static ConfigurationSerializable deserializeObject(Map<String, ?> args, Class<? extends ConfigurationSerializable> clazz) {
+    @Nullable
+    public static ConfigurationSerializable deserializeObject(@NotNull Map<String, ?> args, @NotNull Class<? extends ConfigurationSerializable> clazz) {
         return new ConfigurationSerialization(clazz).deserialize(args);
     }
 
@@ -174,7 +182,8 @@ public class ConfigurationSerialization {
      * @param args Arguments for deserialization
      * @return New instance of the specified class
      */
-    public static ConfigurationSerializable deserializeObject(Map<String, ?> args) {
+    @Nullable
+    public static ConfigurationSerializable deserializeObject(@NotNull Map<String, ?> args) {
         Class<? extends ConfigurationSerializable> clazz = null;
 
         if (args.containsKey(SERIALIZED_TYPE_KEY)) {
@@ -205,7 +214,7 @@ public class ConfigurationSerialization {
      *
      * @param clazz Class to register
      */
-    public static void registerClass(Class<? extends ConfigurationSerializable> clazz) {
+    public static void registerClass(@NotNull Class<? extends ConfigurationSerializable> clazz) {
         DelegateDeserialization delegate = clazz.getAnnotation(DelegateDeserialization.class);
 
         if (delegate == null) {
@@ -222,7 +231,7 @@ public class ConfigurationSerialization {
      * @param alias Alias to register as
      * @see SerializableAs
      */
-    public static void registerClass(Class<? extends ConfigurationSerializable> clazz, String alias) {
+    public static void registerClass(@NotNull Class<? extends ConfigurationSerializable> clazz, @NotNull String alias) {
         aliases.put(alias, clazz);
     }
 
@@ -231,7 +240,7 @@ public class ConfigurationSerialization {
      *
      * @param alias Alias to unregister
      */
-    public static void unregisterClass(String alias) {
+    public static void unregisterClass(@NotNull String alias) {
         aliases.remove(alias);
     }
 
@@ -241,7 +250,7 @@ public class ConfigurationSerialization {
      *
      * @param clazz Class to unregister
      */
-    public static void unregisterClass(Class<? extends ConfigurationSerializable> clazz) {
+    public static void unregisterClass(@NotNull Class<? extends ConfigurationSerializable> clazz) {
         while (aliases.values().remove(clazz)) {
             ;
         }
@@ -254,7 +263,8 @@ public class ConfigurationSerialization {
      * @param alias Alias of the serializable
      * @return Registered class, or null if not found
      */
-    public static Class<? extends ConfigurationSerializable> getClassByAlias(String alias) {
+    @Nullable
+    public static Class<? extends ConfigurationSerializable> getClassByAlias(@NotNull String alias) {
         return aliases.get(alias);
     }
 
@@ -265,7 +275,8 @@ public class ConfigurationSerialization {
      * @param clazz Class to get alias for
      * @return Alias to use for the class
      */
-    public static String getAlias(Class<? extends ConfigurationSerializable> clazz) {
+    @NotNull
+    public static String getAlias(@NotNull Class<? extends ConfigurationSerializable> clazz) {
         DelegateDeserialization delegate = clazz.getAnnotation(DelegateDeserialization.class);
 
         if (delegate != null) {

paper-api/src/main/java/org/bukkit/configuration/serialization/DelegateDeserialization.java

@@ -1,5 +1,7 @@
 package org.bukkit.configuration.serialization;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -18,5 +20,6 @@ public @interface DelegateDeserialization {
      *
      * @return Delegate class
      */
+    @NotNull
     public Class<? extends ConfigurationSerializable> value();
 }

paper-api/src/main/java/org/bukkit/configuration/serialization/SerializableAs.java

@@ -1,5 +1,7 @@
 package org.bukkit.configuration.serialization;
 
+import org.jetbrains.annotations.NotNull;
+
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -30,5 +32,6 @@ public @interface SerializableAs {
      *
      * @return Name to serialize the class as.
      */
+    @NotNull
     public String value();
 }