數據格式：

[SkillDTO(Job=電線工, rankGrade=高級工, r=4),

SkillDTO(Job=監察員, rankGrade=技師, r=5),

SkillDTO(Job=監察員, rankGrade=高級工, r=4),

SkillDTO(skillJob=監察員, rankGrade=中級工, r=3)]

List<SkillDTO> resultList = SkillDTOList.stream().collect(Collectors.toMap(SkillDTO::getJob, Function.identity(),(existing, replacement) -> existing.getR() > replacement.getR() ? existing : replacement)).values().stream().collect(Collectors.toList());

[SkillDTO(Job=11電線工, rankGrade=高級工, r=4),

SkillDTO(Job=監察員, rankGrade=技師, r=5)]