Java日期时间API系列16-----Jdk8中java.time包中的新的日期时间API类，java日期计算3，日期中年月日时分秒的属性值修改等

　　通过Java日期时间API系列8-----Jdk8中java.time包中的新的日期时间API类的LocalDate源码分析 ，可以看出java8设计非常好，实现接口Temporal, TemporalAdjuster, ChronoLocalDate等，有非常丰富的方法。例如：LocalDateTime：的部分方法：

　

包含了年月日，时分秒的属性值修改。Date中如果要进行属性值修改，必须使用Calendar才可以。现在通过将Date转换为LocalDateTime，就能非常方便，线程安全的年月日，时分秒等属性值修改。

// modify property

public static Date withYear(Date date, long newValue){
return with(date, ChronoField.YEAR, newValue);
}

public static LocalDateTime withYear(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.YEAR, newValue);
}

public static LocalDate withYear(LocalDate localDate, long newValue){
return (LocalDate) with(localDate, ChronoField.YEAR, newValue);
}

public static Date withMonth(Date date, long newValue){
return with(date, ChronoField.MONTH_OF_YEAR, newValue);
}

public static LocalDateTime withMonth(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.MONTH_OF_YEAR, newValue);
}

public static LocalDate withMonth(LocalDate localDate, long newValue){
return (LocalDate) with(localDate, ChronoField.MONTH_OF_YEAR, newValue);
}

public static Date withDayOfMonth(Date date, long newValue){
return with(date, ChronoField.DAY_OF_MONTH, newValue);
}

public static LocalDateTime withDayOfMonth(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.DAY_OF_MONTH, newValue);
}

public static LocalDate withDayOfMonth(LocalDate localDate, long newValue){
return (LocalDate) with(localDate, ChronoField.DAY_OF_MONTH, newValue);
}

public static Date withDayOfYear(Date date, long newValue){
return with(date, ChronoField.DAY_OF_YEAR, newValue);
}

public static LocalDateTime withDayOfYear(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.DAY_OF_YEAR, newValue);
}

public static LocalDate withDayOfYear(LocalDate localDate, long newValue){
return (LocalDate) with(localDate, ChronoField.DAY_OF_YEAR, newValue);
}

public static Date withHour(Date date, long newValue){
return with(date, ChronoField.HOUR_OF_DAY, newValue);
}

public static LocalDateTime withHour(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.HOUR_OF_DAY, newValue);
}

public static LocalTime withHour(LocalTime localTime, long newValue){
return (LocalTime) with(localTime, ChronoField.HOUR_OF_DAY, newValue);
}

public static Date withMinute(Date date, long newValue){
return with(date, ChronoField.MINUTE_OF_HOUR, newValue);
}

public static LocalDateTime withMinute(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.MINUTE_OF_HOUR, newValue);
}

public static LocalTime withMinute(LocalTime localTime, long newValue){
return (LocalTime) with(localTime, ChronoField.MINUTE_OF_HOUR, newValue);
}

public static Date withSecond(Date date, long newValue){
return with(date, ChronoField.SECOND_OF_MINUTE, newValue);
}

public static LocalDateTime withSecond(LocalDateTime localDateTime, long newValue){
return (LocalDateTime) with(localDateTime, ChronoField.SECOND_OF_MINUTE, newValue);
}

public static LocalTime withSecond(LocalTime localTime, long newValue){
return (LocalTime) with(localTime, ChronoField.SECOND_OF_MINUTE, newValue);
}

测试类：

@Test
public void dateCalculatorWithTest(){
Date date = new Date();
System.out.println(date);
System.out.println(DateTimeConverterUtil.toLocalDateTime(date));
System.out.println(DateTimeCalculatorUtil.getDayOfYear(date));

System.out.println(DateTimeCalculatorUtil.withYear(date, 2021));
System.out.println(DateTimeCalculatorUtil.withMonth(date, 3));
System.out.println(DateTimeCalculatorUtil.withDayOfMonth(date, 6));
System.out.println(DateTimeCalculatorUtil.withDayOfYear(date, 37));
System.out.println(DateTimeCalculatorUtil.withHour(date, 17));
System.out.println(DateTimeCalculatorUtil.withMinute(date, 30));
System.out.println(DateTimeCalculatorUtil.withSecond(date, 30));
}

@Test
public void dateCalculatorWithTest2(){
LocalDateTime ldt = LocalDateTime.now();
System.out.println(ldt);
System.out.println(ldt.getDayOfYear());

System.out.println(DateTimeCalculatorUtil.withYear(ldt, 2021));
System.out.println(DateTimeCalculatorUtil.withMonth(ldt, 3));
System.out.println(DateTimeCalculatorUtil.withDayOfMonth(ldt, 6));
System.out.println(DateTimeCalculatorUtil.withDayOfYear(ldt, 37));
System.out.println(DateTimeCalculatorUtil.withHour(ldt, 17));
System.out.println(DateTimeCalculatorUtil.withMinute(ldt, 30));
System.out.println(DateTimeCalculatorUtil.withSecond(ldt, 30));
}

输出：

Wed Feb 05 16:20:47 CST 2020
2020-02-05T16:20:47.955
36
Fri Feb 05 16:20:47 CST 2021
Thu Mar 05 16:20:47 CST 2020
Thu Feb 06 16:20:47 CST 2020
Thu Feb 06 16:20:47 CST 2020
Wed Feb 05 17:20:47 CST 2020
Wed Feb 05 16:30:47 CST 2020
Wed Feb 05 16:20:30 CST 2020

2020-02-05T16:21:03.760
36
2021-02-05T16:21:03.760
2020-03-05T16:21:03.760
2020-02-06T16:21:03.760
2020-02-06T16:21:03.760
2020-02-05T17:21:03.760
2020-02-05T16:30:03.760
2020-02-05T16:21:30.760

源代码地址：https://github.com/xkzhangsan/xk-time