java8日期处理

Author: enjoyCoding666

src/main/java/com/date/DateDemo.java

@@ -7,7 +7,8 @@
 import java.util.Date;
 
 public class DateDemo {
-	public static void main(String args[]){
+
+	private static void formatCurrentTime() {
 		Date date1=new Date();
 		long currentTime = System.currentTimeMillis();
 
@@ -17,19 +18,16 @@ public static void main(String args[]){
 
 		System.out.println(date1);
 		System.out.println(formatter.format(date2));
-
-
-
 	}
 
-	public void dateToString(Date date) {
+	public static void dateToString(Date date) {
 		SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
 		String str=sdf.format(date);
 		System.out.println(date+"转化为字符串是："+str);
 	}
 
 
-	public void stringToDate() {
+	public static void stringToDate() {
 		//试着用SimpleDateFormat的parse方法将字符串转化为date类型
 		//MM必须大写。。区分月份和时间
 		DateFormat dateFormat=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
@@ -44,7 +42,7 @@ public void stringToDate() {
 		}
 	}
 
-	public void stringToDate2() {
+	public static void stringToDate2() {
 		String str="2016-07-21 15:41:52";
 		try {
 			Date date=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(str);
@@ -58,4 +56,10 @@ public void stringToDate2() {
 		}
 	}
 
+	public static void compareDate(Date date1,Date date2) {
+		if (date1.compareTo(date2) == 0) {
+			System.out.println(date1+"等于"+date2);
+		}
+	}
+
 }

src/main/java/com/java8/localdate/LocalDateDemo.java

@@ -13,46 +13,57 @@
 public class LocalDateDemo {
 
 
-	public static void main(String[] args) {
-
-//		timeToString();
-
-//		stringToTime();
-
-//		localDateTest();
-
-		monthDiff();
-	}
-
-	private static void timeToString() {
+	public  void timeToString() {
 		// 日期时间转字符串
 		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
-		//当前时间
-		LocalDateTime now = LocalDateTime.now();
-		String nowText = now.format(formatter);
-		System.out.println("nowText为：" + nowText);
+		LocalDateTime dateTime = LocalDateTime.of(2020, 1, 8, 15, 16, 17);
+		String dateTimeStr = dateTime.format(formatter);
+		System.out.println("dateTimeStr为：" + dateTime);
 	}
 
-	private static void stringToTime() {
+	public  void stringToTime() {
 		// 字符串转日期时间
 		DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
 		String datetimeText = "2020-04-01 23:59:59";
-		LocalDateTime localDateTime= LocalDateTime.parse(datetimeText, formatter);
+		LocalDateTime localDateTime = LocalDateTime.parse(datetimeText, formatter);
 		// LocalDateTime的toString()方法，在日期和时间中间加入了"T"字符串
 		System.out.println(localDateTime);
 	}
 
-	private static void localDateTest() {
-		LocalDate date = LocalDate.of(2000, 1, 1);
-		System.out.println("构造的日期为：" + date);
+	public  void generateLocalDate() {
+		LocalDate date = LocalDate.of(2000, 1, 8);
+		LocalDateTime dateTime = LocalDateTime.of(2020, 1, 8, 15, 16, 17);
+		System.out.println("date：" + date);
+		System.out.println("dateTime:" + dateTime);
+	}
+	
+	public  void getLocalDateTimeMonth() {
+		LocalDateTime dateTime = LocalDateTime.of(2020, 1, 8, 15, 16, 17);
+		int year=dateTime.getYear();
+		int month=dateTime.getMonth().getValue();
+		int day=dateTime.getDayOfMonth();
+		System.out.println("dateTime对应的年份为："+year);
+		System.out.println("dateTime对应的年份为："+month);
+		System.out.println("dateTime对应的年份为："+day);
 	}
 
-	private static void monthDiff(){
+	public  void monthDiff() {
 		LocalDate date1 = LocalDate.of(2019, 1, 15);
 		LocalDate date2 = LocalDate.of(2019, 3, 10);
 		Period period = Period.between(date1, date2);
-		System.out.println("相差的年数为"+period.getYears() + "，相差的月数为：" + period.getMonths() +
+		System.out.println("相差的年数为" + period.getYears() + "，相差的月数为：" + period.getMonths() +
 				"，相差的天数为：" + period.getDays());
 	}
 
+	public void addMonthDay() {
+		LocalDateTime dt = LocalDateTime.of(2020, 1, 26, 20, 30, 59);
+		System.out.println(dt);
+		// 加5天减3小时:
+		LocalDateTime dt2 = dt.plusDays(5).minusHours(3);
+		System.out.println(dt2); // 2019-10-31T17:30:59
+		// 减1月:
+		LocalDateTime dt3 = dt2.minusMonths(1);
+		System.out.println(dt3); // 2019-09-30T17:30:59
+	}
+
 }