Map the fields of a class into a Map with fieldName and fieldValue

ReflectionClassFields.java

import org.apache.commons.lang3.tuple.Pair;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class ReflectionClassFields {

	public Map<String, Object> mapClassFieldsValues(Object entity) throws IllegalArgumentException {
		Stream<Field> declaredFields = Stream.of(entity.getClass().getDeclaredFields());
		return declaredFields
			.collect(Collectors.toMap(
				Field::getName,
				field -> {
					try {
						return Pair.of(field.getName(), getFieldValue(entity, field));
					} catch (IllegalAccessException e) {
						throw new RuntimeException(e);
					}
				}
			));
	}

	private Object getFieldValue(Object entity, Field field) throws IllegalAccessException {
		if (Modifier.isPrivate(field.getModifiers())) {
			field.setAccessible(true);
		}
		return field.get(entity);
	}

}