teste.java

package com.luizalabs.repository;

import com.luizalabs.entity.Product;
import com.luizalabs.entity.ProductGroup;
import info.debatty.java.stringsimilarity.Levenshtein;
import org.springframework.stereotype.Repository;

import java.util.*;
import java.util.stream.Collectors;

@Repository
public class ProductGroupRepository {
    public List<ProductGroup> group(List<Product> products) {
        final Map<String, List<Product>> ean = products
                .stream()
                .collect(Collectors.groupingBy(p -> p.getEan()));

        List<Product> eanProduct = ean.get("7898100848355").stream().sorted(Comparator.comparing(Product::getStock).reversed().thenComparing(Product::getPrice)).collect(Collectors.toList());
        
        final Map<String, List<Product>> title = products
                .stream()
                .filter(product -> !Objects.equals(product.getEan(), "7898100848355"))
                .collect(Collectors.groupingBy(p -> p.getTitle()));
        
        final Map<String, List<Product>> brand = products
                .stream()
                .filter(product -> !Objects.equals(product.getEan(), "7898100848355"))
                .collect(Collectors.groupingBy(p -> p.getBrand()));

        List<ProductGroup> productGroupList = Arrays.asList(
                new ProductGroup(eanProduct.get(0).getTitle(), eanProduct)
        );


        return productGroupList;
    }
}