LocalDate

src/chapter5/Example16.java

@@ -0,0 +1,15 @@
+package chapter5;
+
+public class Example16 {
+    public static void main(String[] args) {
+        System.out.println("计算绝对值的结果: " + Math.abs(-10));
+        System.out.println("求大于参数的最小整数: " + Math.ceil(5.6));
+        System.out.println("求小于参数的最大整数: " + Math.floor(-4.2));
+        System.out.println("对小数进行四舍五入后的结果: " + Math.round(-4.6));
+        System.out.println("求两个数的较大值: " + Math.max(2.1, -2.1));
+        System.out.println("求两个数的较小值: " + Math.min(2.1, -2.1));
+        System.out.println("生成一个大于等于0.0小于1.0随机值: " + Math.round(10 * Math.random()));
+        System.out.println("开平方的结果: "+Math.sqrt(4));
+        System.out.println("指数函数的值: "+Math.pow(2, 3));
+    }
+}

src/chapter5/Example17.java

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+package chapter5;
+
+import java.util.Random;
+
+public class Example17 {
+    public static void main(String[] args) {
+        Random r = new Random();    // 不传入种子
+        for (int i = 0; i < 10; i++) {
+            // 随机产生10个[0,100)之间的整数
+            System.out.println(r.nextInt(100));
+        }
+    }
+}

src/chapter5/Example18.java

@@ -0,0 +1,13 @@
+package chapter5;
+
+import java.util.Random;
+
+public class Example18 {
+    public static void main(String[] args) {
+        Random r = new Random(13);
+        // 随机产生10个[0,100)之间的整数
+        for (int i = 0; i < 10; i++) {
+            System.out.println(r.nextInt(100));
+        }
+    }
+}

src/chapter5/Example20.java

@@ -0,0 +1,4 @@
+package chapter5;
+
+public class Example20 {
+}

src/chapter5/Example21.java

@@ -0,0 +1,24 @@
+package chapter5;
+
+import java.time.LocalDate;
+
+public class Example21 {
+    public static void main(String[] args) {
+        LocalDate now = LocalDate.now();
+        LocalDate of = LocalDate.of(2015, 12, 12);
+
+        System.out.println("今年是" + now.getYear() + "年");
+        System.out.println("月份：" + now.getMonth());
+        System.out.println("月份：" + now.getMonthValue());
+        System.out.println("日期：" + now.getDayOfMonth());
+        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("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());
+    }
+}