java8 DateTimeFormatter的使用

DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("EE yyyy-MM-dd hh:mm:ss");
String format = dateTimeFormatter.format(datetime);
System.out.println(format);

// Locale.US 的作用是格式化时,会按照当地的习惯来格式化，如中国是 星期日，美国是Sun
DateTimeFormatter us = DateTimeFormatter.ofPattern("EE yyyy-MM-dd hh:mm:ss",Locale.US);
String us_format = us.format(datetime);
System.out.println(us_format);

//datetime，date，time
LocalDateTime now = LocalDateTime.now();
System.out.println(DateTimeFormatter.ISO_DATE_TIME.format(now));
System.out.println(DateTimeFormatter.ISO_DATE.format(now));
System.out.println(DateTimeFormatter.ISO_TIME.format(now));

//local  datetime，date，time
System.out.println(DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(now));
System.out.println(DateTimeFormatter.ISO_LOCAL_DATE.format(now));
System.out.println(DateTimeFormatter.ISO_LOCAL_TIME.format(now));

//毫秒
Instant now_instance = Instant.now();
System.out.println(DateTimeFormatter.ISO_INSTANT.format(now_instance));