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如何实现java8 list按照元素的某个字段去重

2023-08-21 08:48:04 385

list按照元素的某个字段去重

@Data
@AllArgsConstructor
@NoArgsConstructor
publicclassStudent{
privateIntegerage;
privateStringname;
}

测试数据

ListstudentList=Lists.newArrayList();
studentList.add(newStudent(28,"river"));
studentList.add(newStudent(12,"lucy"));
studentList.add(newStudent(33,"frank"));
studentList.add(newStudent(33,"lucy"));

java8通过treeset去重

ListstudentDistinctList=studentList.stream()
.collect(Collectors.collectingAndThen
(Collectors.toCollection(()->
newTreeSet<>(Comparator.comparing(t->t.getName()))),
ArrayList::new
)
);
System.out.println(newGson().toJson(studentDistinctList));

扩展distinct方法去重

ListstudentDistinct2List=studentList.stream().filter(StreamUtil.distinctByKey(t->t.getName()))
.collect(Collectors.toList());
System.out.println(newGson().toJson(studentDistinct2List));

工具类

publicclassStreamUtil{
/**
*https://stackoverflow.com/questions/23699371/java-8-distinct-by-property
*@paramkeyExtractor
*@param
*@return
*/
publicstaticPredicatedistinctByKey(FunctionkeyExtractor){
Set

如何实现java8 list按照元素的某个字段去重

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