LocalDate

src/chapter5/Example20.java

@@ -1,4 +1,12 @@
 package chapter5;
 
+import java.time.Instant;
+
 public class Example20 {
+    public static void main(String[] args) {
+        Instant now = Instant.now();
+        System.out.println(now);
+        Instant instant = Instant.ofEpochMilli(1000 * 60 * 60 * 24);
+        System.out.println(instant);
+    }
 }

src/chapter5/Example21.java

@@ -14,11 +14,20 @@ public class Example21 {
         System.out.println("今年中的第几天：" + now.getDayOfYear());
         System.out.println("周几：" + now.getDayOfWeek());
 
-        System.out.println("====判断相关的方法====");
+        System.out.println("\n====判断相关的方法====");
 
         System.out.println("of是否在now之前？" + of.isBefore(now));
         System.out.println("of是否在now之后？" + of.isAfter(now));
         System.out.println("of和now是否相等？" + of.isEqual(now));
         System.out.println("of是否闰年？" + of.isLeapYear());
+
+        System.out.println("\n====解析和加减操作====");
+
+        String dateStr = "2020-02-12";
+        LocalDate date = LocalDate.parse(dateStr);
+        System.out.println("把字符串转换为日期对象：" + date);
+        System.out.println("年份加1:" + date.plusYears(1));
+        System.out.println("天数减5:" + date.minusDays(5));
+        System.out.println("指定年份为2024：" + date.withYear(2024));
     }
 }