Merge pull request eugenp#10245 from michael-pratt/BAEL-4663

eric-martin · web-flow · commit f92ca55928da · 2020-11-21T09:45:09.000-06:00
BAEL-4663: Whats new in Java 15
diff --git a/core-java-modules/core-java-15/pom.xml b/core-java-modules/core-java-15/pom.xml
@@ -51,8 +51,8 @@
                 <configuration>
                     <release>${maven.compiler.release}</release>
                     <compilerArgs>--enable-preview</compilerArgs>
-                    <source>15</source>
-                    <target>15</target>
+                    <source>14</source>
+                    <target>14</target>
                 </configuration>
             </plugin>
             <plugin>
diff --git a/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/records/Person.java b/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/records/Person.java
@@ -0,0 +1,15 @@
+package com.baeldung.whatsnew.records;
+
+/**
+ * Java record with a header indicating 2 fields.
+ */
+public record Person(String name, int age) {
+    /**
+     * Public constructor that does some basic validation.
+     */
+    public Person {
+        if (age < 0) {
+            throw new IllegalArgumentException("Age cannot be negative");
+        }
+    }
+}
diff --git a/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/sealedclasses/Employee.java b/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/sealedclasses/Employee.java
@@ -0,0 +1,9 @@
+package com.baeldung.whatsnew.sealedclasses;
+
+import java.util.Date;
+
+public non-sealed class Employee extends Person {
+    public Date getHiredDate() {
+        return new Date();
+    }
+}
diff --git a/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/sealedclasses/Manager.java b/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/sealedclasses/Manager.java
@@ -0,0 +1,4 @@
+package com.baeldung.whatsnew.sealedclasses;
+
+public final class Manager extends Person {
+}
diff --git a/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/sealedclasses/Person.java b/core-java-modules/core-java-15/src/main/java/com/baeldung/whatsnew/sealedclasses/Person.java
@@ -0,0 +1,21 @@
+package com.baeldung.whatsnew.sealedclasses;
+
+import java.util.Date;
+
+public sealed class Person permits Employee, Manager {
+    /**
+     * Demonstration of pattern matching for instanceof
+     *
+     * @param person A Person object
+     * @return
+     */
+    public static void patternMatchingDemo(Person person) {
+        if(person instanceof Employee employee) {
+            Date hiredDate = employee.getHiredDate();
+        }
+
+        if(person instanceof Employee employee && employee.getHiredDate() != null) {
+            Date hiredDate = employee.getHiredDate();
+        }
+    }
+}

-Original file line number
+Diff line change
@@ @@ -0,0 +1,4 @@ @@
 +package com.baeldung.whatsnew.sealedclasses;
++
 +public final class Manager extends Person {
 +}