content: package com.alibaba.fastjson2.writer;
  
  import com.alibaba.fastjson2.JSONWriter;
  
  import java.lang.reflect.Field;
  import java.lang.reflect.Method;
  import java.math.BigInteger;
  import java.util.function.Function;
  
  final class FieldWriterBigIntFunc<T>
          extends FieldWriter<T> {
      final Function<T, BigInteger> function;
  
      FieldWriterBigIntFunc(
              String fieldName,
              int ordinal,
              long features,
              String format,
              String label,
              Field field,
              Method method,
              Function<T, BigInteger> function
      ) {
          super(fieldName, ordinal, features, format, null, label, BigInteger.class, BigInteger.class, null, method);
          this.function = function;
      }
  
      @Override
      public Object getFieldValue(T object) {
          return function.apply(object);
      }
  
      @Override
      public void writeValue(JSONWriter jsonWriter, T object) {
          BigInteger value = (BigInteger) getFieldValue(object);
          jsonWriter.writeBigInt(value, features);
      }
  
      @Override
      public boolean write(JSONWriter jsonWriter, T o) {
          BigInteger value = function.apply(o);
          if (value == null) {
              long features = this.features | jsonWriter.getFeatures();
              if ((features & (JSONWriter.Feature.WriteNulls.mask | JSONWriter.Feature.NullAsDefaultValue.mask)) == 0) {
                  return false;
              }
          }
          writeFieldName(jsonWriter);
          jsonWriter.writeBigInt(value, features);
          return true;
      }
  
      @Override
      public Function getFunction() {
          return function;
      }
  }
  