如何按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)
java.text.Collator
进行不区分大小写和区域设置敏感的 String
比较。下面显示了美国英语如何忽略大小写和重音:
Collator collator = Collator.getInstance(Locale.US);
collator.setStrength(Collator.PRIMARY);
listOfEmployees.sort(Comparator.comparing(Employee::getName, collator.reversed()));
当整理器强度设置为
PRIMARY
时,则在比较过程中只有 PRIMARY
差异被认为是显着的。因此,以下字符串被认为是等效的:
if (collator.compare("abc", "ABC") == 0) {
System.out.println("Strings are equivalent");
}
您可以将其指定为第二个参数以忽略大小写:
Comparator.comparing(Employee::getName, String::compareToIgnoreCase).reversed()
这是多种方法之一:
listofEmployees.stream()
.sorted((o1, o2) -> o1.getName().compareToIgnoreCase(o2.getName()))
.forEach(s -> System.out.println(s.getName()));
看起来有一个比较器通过compareToIgnoreCase对String对象进行排序,您可以在这里阅读文档:https://docs.oracle.com/javase/8/docs/api/java/lang/String.html# CASE_INSENSITIVE_ORDER
Comparator.comparing(Employee::getName, String.CASE_INSENSITIVE_ORDER)
它对我有用
您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()));