如何在下面以不区分大小写的顺序对字符串值进行排序?
List<Employee> listofEmployees = Arrays.asList(
new Employee(1, "aaa", Arrays.asList(123, 345, 678)),
new Employee(1, "bbb", Arrays.asList(91011, 121314, 1516117)),
new Employee(2, "ccc", Arrays.asList(181920, 212223, 242526)),
new Employee(3, "ddd", Arrays.asList(272829, 303132, 333435)),
new Employee(4, "BBB", Arrays.asList(29, 332, 33))
);
我是这样写的:
listofEmployees.stream().sorted(Comparator.comparing(Employee::getName).reversed())
.forEach(s -> System.out.println(s.getName()));
如何在此处传递不区分大小写的字符串选项?
试试这个
Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER)
正如@Tree注释中建议的那样,可以使用java.text.Collator
进行不区分大小写和区分区域设置的String
比较。下面显示了如何忽略美国英语的大小写和重音:
Collator collator = Collator.getInstance(Locale.US);
collator.setStrength(Collator.PRIMARY);
listOfEmployees.sort(Comparator.comparing(Employee::getName, collator.reversed()));
当收集人强度设置为 PRIMARY
时,则在比较过程中只有PRIMARY
差异被认为是显著的。因此,以下字符串被视为等效:
if (collator.compare("abc", "ABC") == 0) {
System.out.println("Strings are equivalent");
}
您可以将其指定为忽略案例的第二个参数:
Comparator.comparing(Employee::getName, String::compareToIgnoreCase).reversed()
这是多种方式之一:
listofEmployees.stream()
.sorted((o1, o2) -> o1.getName().compareToIgnoreCase(o2.getName()))
.forEach(s -> System.out.println(s.getName()));
比较器通过比较对字符串对象进行排序,你可以在这里阅读文档:https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#CASE_INSENSITIVE_ORDER
你可以像这样小写或大写:
listofEmployees.stream()
.sorted(Comparator.comparing((Employee e) -> e.getName()
.toLowerCase()) // or toUpperCase
.reversed())
.forEach(s -> System.out.println(s.getName()));