From 1fba6f01270e13debfb4ecd5a48d5e5eb7b266d5 Mon Sep 17 00:00:00 2001
From: Tarun Jain <tarunalways@gmail.com>
Date: Wed, 4 Nov 2020 14:09:33 +0530
Subject: [PATCH] BAEL-4645|Transient keyword in Java

---
 .../java/com/baeldung/transientkw/Book.java   | 42 ++++++++++++++++++
 .../com/baeldung/transientkw/BookSerDe.java   | 44 +++++++++++++++++++
 .../transientkw/TransientUnitTest.java        | 35 +++++++++++++++
 3 files changed, 121 insertions(+)
 create mode 100644 core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/Book.java
 create mode 100644 core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/BookSerDe.java
 create mode 100644 core-java-modules/core-java-lang-3/src/test/java/com/baeldung/transientkw/TransientUnitTest.java

diff --git a/core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/Book.java b/core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/Book.java
new file mode 100644
index 0000000000..5822d83841
--- /dev/null
+++ b/core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/Book.java
@@ -0,0 +1,42 @@
+package com.baeldung.transientkw;
+
+import java.io.Serializable;
+
+public class Book implements Serializable {
+
+    private static final long serialVersionUID = -2936687026040726549L;
+
+    private String bookName;
+    private transient String description;
+    private transient int copies;
+    private final transient String bookCategory = "Fiction";
+
+    public String getBookName() {
+        return bookName;
+    }
+
+    public void setBookName(String bookName) {
+        this.bookName = bookName;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+    public int getCopies() {
+        return copies;
+    }
+
+    public void setCopies(int copies) {
+        this.copies = copies;
+    }
+
+    public String getBookCategory() {
+        return bookCategory;
+    }
+
+}
diff --git a/core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/BookSerDe.java b/core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/BookSerDe.java
new file mode 100644
index 0000000000..38e018baa3
--- /dev/null
+++ b/core-java-modules/core-java-lang-3/src/main/java/com/baeldung/transientkw/BookSerDe.java
@@ -0,0 +1,44 @@
+package com.baeldung.transientkw;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+
+public class BookSerDe {
+    static String fileName = "book.ser";
+
+    /**
+     * Method to serialize Book objects to the file
+     * @throws FileNotFoundException 
+     */
+    public static void serialize(Book book) throws Exception {
+        FileOutputStream file = new FileOutputStream(fileName);
+        ObjectOutputStream out = new ObjectOutputStream(file);
+
+        out.writeObject(book);
+
+        out.close();
+        file.close();
+    }
+
+    /**
+     * Method to deserialize the person object
+     * @return book
+     * @throws IOException, ClassNotFoundException
+     */
+    public static Book deserialize() throws Exception {
+        FileInputStream file = new FileInputStream(fileName);
+        ObjectInputStream in = new ObjectInputStream(file);
+
+        Book book = (Book) in.readObject();
+
+        in.close();
+        file.close();
+
+        return book;
+    }
+
+}
diff --git a/core-java-modules/core-java-lang-3/src/test/java/com/baeldung/transientkw/TransientUnitTest.java b/core-java-modules/core-java-lang-3/src/test/java/com/baeldung/transientkw/TransientUnitTest.java
new file mode 100644
index 0000000000..cf63a0ddda
--- /dev/null
+++ b/core-java-modules/core-java-lang-3/src/test/java/com/baeldung/transientkw/TransientUnitTest.java
@@ -0,0 +1,35 @@
+package com.baeldung.transientkw;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import org.junit.jupiter.api.Test;
+
+class TransientUnitTest {
+
+    @Test
+    void givenTransient_whenSerDe_thenVerifyValues() throws Exception {
+        Book book = new Book();
+        book.setBookName("Java Reference");
+        book.setDescription("will not be saved");
+        book.setCopies(25);
+        
+        BookSerDe.serialize(book);
+        Book book2 = BookSerDe.deserialize();
+        
+        assertEquals("Java Reference", book2.getBookName());
+        assertNull(book2.getDescription());
+        assertEquals(0, book2.getCopies());
+    }
+    
+    @Test
+    void givenFinalTransient_whenSerDe_thenValuePersisted() throws Exception {
+        Book book = new Book();
+        
+        BookSerDe.serialize(book);
+        Book book2 = BookSerDe.deserialize();
+        
+        assertEquals("Fiction", book2.getBookCategory());     
+    }
+
+}