From 0b9bb44781f1e79f67646a6e49595459655ef271 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Dupire?= <dupirefr@users.noreply.github.com>
Date: Tue, 14 Aug 2018 08:26:57 +0200
Subject: [PATCH] [BAEL-2020] Differences between final, finally and finalize
 in Java (#4848)

* [BAEL-2020] Examples code

* [BAEL-2020] Moving classes into 'keywords' package
---
 .../keywords/finalize/FinalizeObject.java     | 18 ++++++++++++
 .../baeldung/keywords/finalkeyword/Child.java | 15 ++++++++++
 .../keywords/finalkeyword/GrandChild.java     |  5 ++++
 .../keywords/finalkeyword/Parent.java         | 23 +++++++++++++++
 .../finallykeyword/FinallyExample.java        | 29 +++++++++++++++++++
 5 files changed, 90 insertions(+)
 create mode 100644 core-java/src/main/java/com/baeldung/keywords/finalize/FinalizeObject.java
 create mode 100644 core-java/src/main/java/com/baeldung/keywords/finalkeyword/Child.java
 create mode 100644 core-java/src/main/java/com/baeldung/keywords/finalkeyword/GrandChild.java
 create mode 100644 core-java/src/main/java/com/baeldung/keywords/finalkeyword/Parent.java
 create mode 100644 core-java/src/main/java/com/baeldung/keywords/finallykeyword/FinallyExample.java

diff --git a/core-java/src/main/java/com/baeldung/keywords/finalize/FinalizeObject.java b/core-java/src/main/java/com/baeldung/keywords/finalize/FinalizeObject.java
new file mode 100644
index 0000000000..af0449c0da
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/keywords/finalize/FinalizeObject.java
@@ -0,0 +1,18 @@
+package com.baeldung.keywords.finalize;
+
+public class FinalizeObject {
+
+    @Override
+    protected void finalize() throws Throwable {
+        System.out.println("Execute finalize method");
+        super.finalize();
+    }
+
+    public static void main(String[] args) throws Exception {
+        FinalizeObject object = new FinalizeObject();
+        object = null;
+        System.gc();
+        Thread.sleep(1000);
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/keywords/finalkeyword/Child.java b/core-java/src/main/java/com/baeldung/keywords/finalkeyword/Child.java
new file mode 100644
index 0000000000..8615c78652
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/keywords/finalkeyword/Child.java
@@ -0,0 +1,15 @@
+package com.baeldung.keywords.finalkeyword;
+
+public final class Child extends Parent {
+
+    @Override
+    void method1(int arg1, final int arg2) {
+        // OK
+    }
+
+/*    @Override
+    void method2() {
+        // Compilation error
+    }*/
+
+}
diff --git a/core-java/src/main/java/com/baeldung/keywords/finalkeyword/GrandChild.java b/core-java/src/main/java/com/baeldung/keywords/finalkeyword/GrandChild.java
new file mode 100644
index 0000000000..1530c5037f
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/keywords/finalkeyword/GrandChild.java
@@ -0,0 +1,5 @@
+package com.baeldung.keywords.finalkeyword;
+
+/*public class GrandChild extends Child {
+    // Compilation error
+}*/
diff --git a/core-java/src/main/java/com/baeldung/keywords/finalkeyword/Parent.java b/core-java/src/main/java/com/baeldung/keywords/finalkeyword/Parent.java
new file mode 100644
index 0000000000..5cd2996e7a
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/keywords/finalkeyword/Parent.java
@@ -0,0 +1,23 @@
+package com.baeldung.keywords.finalkeyword;
+
+public class Parent {
+
+    int field1 = 1;
+    final int field2 = 2;
+
+    Parent() {
+        field1 = 2; // OK
+//        field2 = 3; // Compilation error
+    }
+
+    void method1(int arg1, final int arg2) {
+        arg1 = 2; // OK
+//        arg2 = 3; // Compilation error
+    }
+
+    final void method2() {
+        final int localVar = 2; // OK
+//        localVar = 3; // Compilation error
+    }
+
+}
diff --git a/core-java/src/main/java/com/baeldung/keywords/finallykeyword/FinallyExample.java b/core-java/src/main/java/com/baeldung/keywords/finallykeyword/FinallyExample.java
new file mode 100644
index 0000000000..3c0aee3196
--- /dev/null
+++ b/core-java/src/main/java/com/baeldung/keywords/finallykeyword/FinallyExample.java
@@ -0,0 +1,29 @@
+package com.baeldung.keywords.finallykeyword;
+
+public class FinallyExample {
+
+    public static void main(String args[]) throws Exception {
+        try {
+            System.out.println("Execute try block");
+            throw new Exception();
+        } catch (Exception e) {
+            System.out.println("Execute catch block");
+        } finally {
+            System.out.println("Execute finally block");
+        }
+
+        try {
+            System.out.println("Execute try block");
+        } finally {
+            System.out.println("Execute finally block");
+        }
+
+        try {
+            System.out.println("Execute try block");
+            throw new Exception();
+        } finally {
+            System.out.println("Execute finally block");
+        }
+    }
+
+}