LocalDate、LocalTime、LocalTimeDate用法及计算时间差

java8新增了LocalDate、LocalTime、LocalTimeDate等，相比于之前的Date，新的类是线程安全的。
整理了一下各个场景下的用法，上代码：

package dateTest;

import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoField;
import java.time.temporal.ChronoUnit;

public class DateTest {
    public static void main(String[] args) {
        LocalDate localDate = LocalDate.now();
        System.out.println("获取当前日期==" + localDate);
        System.out.println("获取月份==" + localDate.getMonthValue());
        System.out.println("获取月份==" + localDate.getMonth());
        System.out.println("获取年==" + localDate.getYear());
        System.out.println("获取日==" + localDate.getDayOfMonth());
        System.out.println("获取周==" + localDate.get(ChronoField.DAY_OF_WEEK));
        System.out.println("获取周==" + localDate.getDayOfWeek());
        
        LocalTime localTime = LocalTime.now();
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("HH:mm:ss");
        String time = dateTimeFormatter.format(localTime);
        System.out.println("获取时分秒==" + localTime);
        System.out.println("获取时分秒==" + time);
        
        LocalDateTime localDateTime = LocalDateTime.now();
        DateTimeFormatter dateTimeFormatter1 = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        String createTime = dateTimeFormatter1.format(localDateTime);
        System.out.println("获取年月日时分秒==" + createTime);
        
        LocalDateTime dateTime = LocalDateTime.of(localDate, localTime);
        System.out.println("获取年月日时分秒==" + dateTimeFormatter1.format(dateTime));
        
        LocalDateTime dateTime2 = LocalDateTime.parse("2020-05-20 20:20:20", dateTimeFormatter1);
        System.out.println("字符串转换locaDateTime==" + dateTime2);
        
        //计算时间差
        Duration duration = Duration.between(dateTime2,  localDateTime );
        System.out.println("相差天数==" + duration.toDays());
        System.out.println("相差毫秒数==" + duration.toMillis());
        System.out.println("相差分钟数==" + duration.toMinutes());
        System.out.println("相差小时数==" + duration.toHours());
        System.out.println("相差纳秒数==" + duration.toNanos());
        
        //月份时间差
        LocalDate start = LocalDate.parse("2020-01-28");
        LocalDate end = LocalDate.parse("2020-06-03");
        long year = start.until(end, ChronoUnit.YEARS);
        long month = start.until(end, ChronoUnit.MONTHS);
        long days = start.until(end, ChronoUnit.DAYS);
        System.out.println("间隔：" + year + "年");
        System.out.println("间隔：" + month + "月");
        System.out.println("间隔：" + days + "天");
        
    }
    
    
    
}

运行结果如下图：

LocalDateconsole结果