仅在一个属性上序列化null的moshi自定义限定符注释

import com.squareup.moshi.JsonQualifier;

@Retention(AnnotationRetention.RUNTIME)
@JsonQualifier
public @interface NullSerialization {
}

import com.squareup.moshi.JsonAdapter;
import com.squareup.moshi.JsonReader;
import com.squareup.moshi.JsonWriter;

import java.io.IOException;

public class NullSerializationAdapter<T> extends JsonAdapter<T> {
    private final JsonAdapter<T> delegate;

    public NullSerializationAdapter(JsonAdapter<T> delegate) {
        this.delegate = delegate;
    }

    @Override
    public void toJson(JsonWriter writer, T value) throws IOException {
        if (value == null) {
            writer.nullValue();
        } else {
            delegate.toJson(writer, value);
        }
    }

    @Override
    public T fromJson(JsonReader reader) throws IOException {
        return delegate.fromJson(reader);
    }
}

public class Person {
    @NullSerialization
    String name;
    int age;
}

Moshi moshi = new Moshi.Builder()
        .add(new JsonAdapter.Factory() {
            @Override
            public JsonAdapter<?> create(Type type, Set<? extends Annotation> annotations, Moshi moshi) {
                for (Annotation annotation : annotations) {
                    if (annotation instanceof NullSerialization) {
                        JsonAdapter<Object> delegateAdapter = moshi.nextAdapter(this, type, annotations);
                        return new NullSerializationAdapter<>(delegateAdapter);
                    }
                }
                return null;
            }
        })
        .build();