Java日期时间与正则表达式超详细整理(适合新手入门)

LocalDate today = LocalDate.now();
LocalDate myBirthday = LocalDate.of(2000, Month.JANUARY, 1);

LocalTime now = LocalTime.now();
LocalTime sixThirty = LocalTime.of(6, 30);

LocalDateTime now = LocalDateTime.now();
LocalDateTime dateTime = LocalDateTime.of(2023, Month.JANUARY, 1, 6, 30);

LocalDateTime now = LocalDateTime.now();
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
String formattedDateTime = now.format(formatter);

Pattern pattern = Pattern.compile("regex");

String input = "example string";
Pattern pattern = Pattern.compile("example.*");
Matcher matcher = pattern.matcher(input);
if (matcher.matches()) {
    System.out.println("Match found");
}

String input = "example string";
Pattern pattern = Pattern.compile("example.*");
Matcher matcher = pattern.matcher(input);
if (matcher.find()) {
    System.out.println("Match found at index " + matcher.start());
}

String input = "example string";
Pattern pattern = Pattern.compile("example");
Matcher matcher = pattern.matcher(input);
String output = matcher.replaceAll("replacement");
System.out.println(output);

String input = "Example String";
Pattern pattern = Pattern.compile("example.*", Pattern.CASE_INSENSITIVE);
Matcher matcher = pattern.matcher(input);
if (matcher.matches()) {
    System.out.println("Match found");
}

// 日期各种格式yyyy-MM-dd HH:mm:ss、 yyyy-MM-dd等
String dateRgx = "(([1-3][0-9]{3})[-]{0,1}(((0[13578]|1[02])[-]{0,1}(0[1-9]|[12][0-9]|3[01]))|((0[469]|11)[-]{0,1}(0[1-9]|[12][0-9]|30))|(02-(0[1-9]|[1][0-9]|2[0-8])))\\s\\d{1,2}:\\d{1,2}:\\d{1,2})|(([1-3][0-9]{3})[-]{0,1}(((0[13578]|1[02])[-]{0,1}(0[1-9]|[12][0-9]|3[01]))|((0[469]|11)-(0[1-9]|[12][0-9]|30))|(02-(0[1-9]|[1][0-9]|2[0-8])))\\s\\d{1,2}:\\d{1,2})|(([1-3][0-9]{3})[-]{0,1}(((0[13578]|1[02])[-]{0,1}(0[1-9]|[12][0-9]|3[01]))|((0[469]|11)[-]{0,1}(0[1-9]|[12][0-9]|30))|(02-(0[1-9]|[1][0-9]|2[0-8]))))";
String date1 = "2019-08-28";
String date2 = "abc";
System.out.println(date1.matches(dateRgx));//true
System.out.println(date2.matches(dateRgx));//false