Java时间工具类LocalTime

嘚吧嘚

本篇文章整理一下有关LocalTime工具类的用法。个人感觉单独使用LocalTime类的几率不大，使用频率最高的应该是LocalDateTime，但是既然都学习了，自然要全面一点。

LocalTime - API

获取时间

函数声明	描述
static LocalTime now()	获取默认时区的当前时间
static LocalTime now(ZoneId zone)	获取指定时区的当前时间
static LocalTime now(Clock clock)	从指定时钟获取当前时间
static LocalTime of(int hour, int minute, int second)	根据指定的时(0-23)、分(0-59)、秒(0-59)获取LocalTime实例

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
// 获取当前时间
LocalTime now = LocalTime.now();
LocalTime time1 = LocalTime.now(ZoneId.of("America/New_York"));
LocalTime time2 = LocalTime.now(Clock.systemDefaultZone());
LocalTime time3 = LocalTime.of(19, 12, 5);

System.out.println("now : " + now.format(formatter) + " " + ZoneId.systemDefault());
System.out.println("time1 : " + time1.format(formatter) + " America/New_York");
System.out.println("time2 : " + time2.format(formatter));
System.out.println("time3 : " + time3.format(formatter));

获取时分秒

函数声明	描述
int getHour()	获取小时
int getMinute()	获取分钟
int getSecond()	获取秒钟
int getNano()	获取纳秒

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
// 获取当前时间
LocalTime time = LocalTime.of(19, 12, 5);
System.out.println("time : " + time.format(formatter));

System.out.println("getHour : " + time.getHour());
System.out.println("getMinute : " + time.getMinute());
System.out.println("getSecond : " + time.getSecond());
System.out.println("getNano : " + time.getNano());

增减时分秒

函数声明	描述
LocalTime plusHours(long hoursToAdd)	增加小时
LocalTime plusMinutes(long minutesToAdd)	增加分钟
LocalTime plusSeconds(long secondstoAdd)	增加秒
LocalTime plusNanos(long nanosToAdd)	增加纳秒
LocalTime minusHours(long hoursToSubtract)	减少小时
LocalTime minusMinutes(long minutesToSubtract)	减少分钟
LocalTime minusSeconds(long secondsToSubtract)	减少秒
LocalTime minusNanos(long nanosToSubtract)	减少纳秒

plusXxx是增加时间，minusXxx是减少时间，但查看源码可以发现minusXxx还是用的plusXxx，所以这两类方法传参可为正数，也可为负数。正负号相同、数字相同时效果相反。

以小时和分钟为例

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
// 获取当前时间
LocalTime time = LocalTime.of(19, 12, 5);
System.out.println("time : " + time.format(formatter));

System.out.println("plusHours : " + time.plusHours(10));
System.out.println("minusHours : " + time.minusHours(-10));

System.out.println("plusMinutes : " + time.plusMinutes(15));
System.out.println("minusMinutes : " + time.minusMinutes(-15));

替换时间

函数声明	描述
LocalTime withHour(int hour)	替换小时(0-23)
LocalTime withMinute(int minute)	替换分钟(0-59)
LocalTime withSecond(int second)	替换秒(0-59)
LocalTime withNano(int nanoOfSecond)	替换纳秒(0-999999999)

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
// 获取当前时间
LocalTime time = LocalTime.of(19, 12, 5);
System.out.println("time : " + time.format(formatter));

System.out.println("withHour : " + time.withHour(10));
System.out.println("withMinute : " + time.withMinute(15));
System.out.println("withSecond : " + time.withSecond(26));
System.out.println("withNano : " + time.withNano(36));

比较时间

函数声明	描述
int compareTo(LocalTime other)	时间与另一个时间比较，x = y：0，x < y：-1，x > y:：1
boolean isAfter(LocalTime other)	检查时间是否在指定时间之后
boolean isBefore(LocalTime other)	检查时间是否在指定时间之前

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("HH:mm:ss");
// 获取当前时间
LocalTime time1 = LocalTime.of(19, 12, 5);
LocalTime time2 = LocalTime.of(18, 12, 5);
LocalTime time3 = LocalTime.of(20, 12, 5);
LocalTime time4 = LocalTime.of(19, 12, 5);

String timeStr1 = time1.format(formatter);
String timeStr2 = time2.format(formatter);
String timeStr3 = time3.format(formatter);
String timeStr4 = time4.format(formatter);
System.out.println("time1 : " + timeStr1);
System.out.println("time2 : " + timeStr2);
System.out.println("time3 : " + timeStr3);
System.out.println("time4 : " + timeStr4);
// 比较日期大小
System.out.println(timeStr1 + " = " + timeStr2 + " : " + time1.compareTo(time2));
System.out.println(timeStr1 + " = " + timeStr4 + " : " + time1.compareTo(time4));
System.out.println(timeStr1 + " = " + timeStr3 + " : " + time1.compareTo(time3));
System.out.println(timeStr1 + " > " + timeStr2 + " : " + time1.isAfter(time2));
System.out.println(timeStr1 + " < " + timeStr2 + " : " + time1.isBefore(time2));

欢迎补充。