content: /*
   * Copyright 2024-2025 the original author or authors.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      https://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.alibaba.cloud.ai.graph.serializer.std;
  
  import com.alibaba.cloud.ai.graph.serializer.Serializer;
  
  import java.io.IOException;
  import java.io.ObjectInput;
  import java.io.ObjectOutput;
  import java.util.Optional;
  
  public interface NullableObjectSerializer<T> extends Serializer<T> {
  
  	default void writeNullableObject(Object object, ObjectOutput out) throws IOException {
  		if (object == null) {
  			out.writeByte(0);
  		}
  		else {
  			out.writeByte(1);
  			out.writeObject(object);
  		}
  	}
  
  	default Optional<Object> readNullableObject(ObjectInput in) throws IOException, ClassNotFoundException {
  		byte b = in.readByte();
  		return (b == 0) ? Optional.empty() : Optional.of(in.readObject());
  	}
  
  	default void writeNullableUTF(String object, ObjectOutput out) throws IOException {
  		if (object == null) {
  			out.writeByte(0);
  		}
  		else {
  			out.writeByte(1);
  			out.writeUTF(object);
  		}
  	}
  
  	default Optional<String> readNullableUTF(ObjectInput in) throws IOException {
  		byte b = in.readByte();
  		if (b == 0) {
  			return Optional.empty();
  		}
  		return Optional.of(in.readUTF());
  	}
  
  }
  