如何根據(jù)性別枚舉類型創(chuàng)建 N 個(gè)列表？如果我有 3 個(gè)可能的 GENDER 枚舉（男性、女性、其他），我需要 3 個(gè)列表。如何使用 java 8 流 API 實(shí)現(xiàn)此目的？在這種情況下，我需要像帶有 3 個(gè)鍵的 MAP 之類的東西。genderMap.get(GENDER.male)。Map<GENDER, List<Person>> genderMap;嘗試使用 partitioningByMap<Boolean, List<Person>> genderMap= people.stream().collect(Collectors.partitioningBy(malePredicate()));System.out.println("MALE "+genderMap.get(true));System.out.println("FEMALE "+genderMap.get(false));private static Predicate<Person> malePredicate(){ return p -> p.getGender() != null && p.getGender().equalsIgnoreCase("male");}private static Predicate<Person> femalePredicate(){ return p -> p.getGender() != null && p.getGender().equalsIgnoreCase("female");}MALE [Person [id=1, name=SAMPLE_1, age=11, gender=male, sal=100, monthlyExpenseAmount=120.00], Person [id=2, name=SAMPLE_2, age=12, gender=male, sal=100 , monthlyExpenseAmount=120.00]]FEMALE [Person [id=0, name=SAMPLE_0, age=10, gender=other, sal=100, monthlyExpenseAmount=120.00], Person [id=3, name=SAMPLE_3, age=13, gender=female, sal=100 , monthlyExpenseAmount=100.00], 人 [id=4, name=SAMPLE_4, age=14, gender=female, sal=100, monthlyExpenseAmount=100.00], Person [id=5, name=SAMPLE_5, age=15, gender=female , sal=100, monthlyExpenseAmount=100.00]]
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GCT1015
TA貢獻(xiàn)1827條經(jīng)驗(yàn) 獲得超4個(gè)贊
.partitioningBy()用于將結(jié)果分成 2 組。
Map<Gender, List<Person>> genderMap = people.stream() .collect(Collectors.groupingBy(Person::getGender));
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