Added Json util file to avoid multiple identical instances of Gson object

Core/src/main/java/fr/pandacube/lib/core/db/SQLElement.java

@@ -19,10 +19,10 @@ import java.util.UUID;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.MoreObjects.ToStringHelper;
-import com.google.gson.Gson;
 import com.google.gson.JsonObject;
 
 import fr.pandacube.lib.core.util.EnumUtil;
+import fr.pandacube.lib.core.util.Json;
 import fr.pandacube.lib.core.util.Log;
 
 public abstract class SQLElement<E extends SQLElement<E>> {
@@ -398,7 +398,7 @@ public abstract class SQLElement<E extends SQLElement<E>> {
 	public JsonObject asJsonObject() {
 		JsonObject json = new JsonObject();
 		for (SQLField<E, ?> f : getFields().values()) {
-			json.add(f.getName(), new Gson().toJsonTree(get(f)));
+			json.add(f.getName(), Json.gson.toJsonTree(get(f)));
 		}
 		return json;
 	}

Core/src/main/java/fr/pandacube/lib/core/util/Json.java

@@ -0,0 +1,104 @@
+package fr.pandacube.lib.core.util;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.RecordComponent;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonToken;
+import com.google.gson.stream.JsonWriter;
+
+public class Json {
+	public static final Gson gson = build(b -> b);
+	public static final Gson gsonPrettyPrinting = build(b -> b.setPrettyPrinting());
+	public static final Gson gsonSerializeNulls = build(b -> b.serializeNulls());
+	public static final Gson gsonSerializeNullsPrettyPrinting = build(b -> b.serializeNulls().setPrettyPrinting());
+
+
+	private static Gson build(Function<GsonBuilder, GsonBuilder> builderModifier) {
+		return builderModifier
+				.apply(new GsonBuilder().registerTypeAdapterFactory(new RecordAdapterFactory()).setLenient()).create();
+	}
+
+
+
+
+	// from https://github.com/google/gson/issues/1794#issuecomment-812964421
+	private static class RecordAdapterFactory implements TypeAdapterFactory {
+		@Override
+		public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+			@SuppressWarnings("unchecked")
+			Class<T> clazz = (Class<T>) type.getRawType();
+			if (!clazz.isRecord() || clazz == Record.class) {
+				return null;
+			}
+			return new RecordTypeAdapter<>(gson, this, type);
+		}
+	}
+
+	private static class RecordTypeAdapter<T> extends TypeAdapter<T> {
+		private Gson gson;
+		private TypeAdapterFactory factory;
+		private TypeToken<T> type;
+
+		public RecordTypeAdapter(Gson gson, TypeAdapterFactory factory, TypeToken<T> type) {
+			this.gson = gson;
+			this.factory = factory;
+			this.type = type;
+		}
+
+		@Override
+		public void write(JsonWriter out, T value) throws IOException {
+			gson.getDelegateAdapter(factory, type).write(out, value);
+		}
+
+		@Override
+		public T read(JsonReader reader) throws IOException {
+			if (reader.peek() == JsonToken.NULL) {
+				reader.nextNull();
+				return null;
+			} else {
+				@SuppressWarnings("unchecked")
+				Class<T> clazz = (Class<T>) type.getRawType();
+
+				RecordComponent[] recordComponents = clazz.getRecordComponents();
+				Map<String, TypeToken<?>> typeMap = new HashMap<>();
+				for (int i = 0; i < recordComponents.length; i++) {
+					typeMap.put(recordComponents[i].getName(), TypeToken.get(recordComponents[i].getGenericType()));
+				}
+				var argsMap = new HashMap<String, Object>();
+				reader.beginObject();
+				while (reader.hasNext()) {
+					String name = reader.nextName();
+					argsMap.put(name, gson.getAdapter(typeMap.get(name)).read(reader));
+				}
+				reader.endObject();
+
+				var argTypes = new Class<?>[recordComponents.length];
+				var args = new Object[recordComponents.length];
+				for (int i = 0; i < recordComponents.length; i++) {
+					argTypes[i] = recordComponents[i].getType();
+					args[i] = argsMap.get(recordComponents[i].getName());
+				}
+				Constructor<T> constructor;
+				try {
+					constructor = clazz.getDeclaredConstructor(argTypes);
+					constructor.setAccessible(true);
+					return constructor.newInstance(args);
+				} catch (NoSuchMethodException | InstantiationException | SecurityException | IllegalAccessException
+						| IllegalArgumentException | InvocationTargetException e) {
+					throw new RuntimeException(e);
+				}
+			}
+		}
+	}
+}

Core/src/main/java/fr/pandacube/lib/core/util/ServerPropertyFile.java

@@ -7,14 +7,10 @@ import java.io.FileReader;
 import java.io.FileWriter;
 import java.io.IOException;
 
-import com.google.gson.Gson;
-import com.google.gson.GsonBuilder;
 import com.google.gson.JsonSyntaxException;
 
 public class ServerPropertyFile {
 
-	private static final Gson SERIALIZER = new GsonBuilder().setPrettyPrinting().create();
-
 	private transient File file;
 	
 	private String name = "default_name";
@@ -39,7 +35,7 @@ public class ServerPropertyFile {
 	public boolean loadFromFile() {
 		try (BufferedReader in = new BufferedReader(new FileReader(file))) {
 
-			ServerPropertyFile dataFile = SERIALIZER.fromJson(in, getClass());
+			ServerPropertyFile dataFile = Json.gsonPrettyPrinting.fromJson(in, getClass());
 			
 			name = dataFile.name;
 			memory = dataFile.memory;
@@ -61,7 +57,7 @@ public class ServerPropertyFile {
 
 	public boolean save() {
 		try (BufferedWriter out = new BufferedWriter(new FileWriter(file, false))) {
-			SERIALIZER.toJson(this, out);
+			Json.gsonPrettyPrinting.toJson(this, out);
 			out.flush();
 			return true;
 		} catch (IOException e) {

Core/src/main/java/fr/pandacube/lib/core/util/TypeConverter.java

@@ -5,7 +5,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 
 /**
@@ -128,7 +127,7 @@ public class TypeConverter {
 		}
 		
 		if (o instanceof JsonElement) {
-			o = new Gson().fromJson((JsonElement)o, Object.class);
+			o = Json.gson.fromJson((JsonElement)o, Object.class);
 		}
 		
 		if (o instanceof Map) {
@@ -175,7 +174,7 @@ public class TypeConverter {
 		}
 		
 		if (o instanceof JsonElement) {
-			o = new Gson().fromJson((JsonElement)o, Object.class);
+			o = Json.gson.fromJson((JsonElement)o, Object.class);
 		}