Spring GenericConversionService

org/springframework/core/convert/support/GenericConversionService

542  @Nullable
543  public GenericConverter find(TypeDescriptor sourceType, TypeDescriptor targetType) {
544      // Search the full type hierarchy
545      List<Class<?>> sourceCandidates = getClassHierarchy(sourceType.getType());
546      List<Class<?>> targetCandidates = getClassHierarchy(targetType.getType());
547      for (Class<?> sourceCandidate : sourceCandidates) {
548          for (Class<?> targetCandidate : targetCandidates) {
549              ConvertiblePair convertiblePair = new ConvertiblePair(sourceCandidate, targetCandidate);
550              GenericConverter converter = getRegisteredConverter(sourceType, targetType, convertiblePair);
551              if (converter != null) {
552                  return converter;
553              }
554          }
555      }
556      return null;
557  }
558
559  @Nullable
560  private GenericConverter getRegisteredConverter(TypeDescriptor sourceType,
561          TypeDescriptor targetType, ConvertiblePair convertiblePair) {
562
563      // Check specifically registered converters
564      ConvertersForPair convertersForPair = this.converters.get(convertiblePair);
565      if (convertersForPair != null) {
566          GenericConverter converter = convertersForPair.getConverter(sourceType, targetType);
567          if (converter != null) {
568              return converter;
569          }
570      }
571      // Check ConditionalConverters for a dynamic match
572      for (GenericConverter globalConverter : this.globalConverters) {
573          if (((ConditionalConverter) globalConverter).matches(sourceType, targetType)) {
574              return globalConverter;
575          }
576      }
577        return null;
578  }

line 550 maybe

GenericConverter converter = getRegisteredConverter(TypeDescriptor.valueOf(sourceCandidate), TypeDescriptor.valueOf(targetCandidate), convertiblePair);

not

GenericConverter converter = getRegisteredConverter(sourceType, targetType, convertiblePair);

because line572-576 repeat execute many times with same paramters sourceType and targetType