List操作
List<Student> list = new ArrayList<>();
list.forEach(item ->{
System.out.println("\n"+item.getAge()+":"+item.getSex());
});
list.stream().filter(item-> item.getAge() > 18).collect(Collectors.toList());
list.stream().sorted((s1,s2) -> s1.getAge().compareTo(s2.getAge())).collect(Collectors.toList());
List<Student> resultStudent = new ArrayList<>();
resultStudent.addAll(list.stream().sorted((v1, v2) -> {
return v1.getAge() - v2.getAge() > 0 ? -1 : 1;
}).collect(Collectors.toList()));
Collections.sort(list);
Collections.reverse(list);
Collections.shuffle(list);
Map操作
Map<String, Long> allYearList = new ConcurrentHashMap<>();
Map<String, Long> resultYear = allYearList.entrySet().stream().sorted(Map.Entry.<String, Long>comparingByKey().reversed()).collect(
Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue,
(oldVal, newVal) -> oldVal, LinkedHashMap::new)
);
Map<String, Long> resultYear = allYearList.entrySet().stream().sorted(Map.Entry.<String, Long>comparingByValue().reversed()).collect(
Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue,
(oldVal, newVal) -> oldVal, LinkedHashMap::new)
);