From 0838279c6afa9bf92a2a89cdb2edcafaddd1a039 Mon Sep 17 00:00:00 2001
From: ACHRAF TAITAI <43656331+achraftt@users.noreply.github.com>
Date: Wed, 15 Nov 2023 22:16:28 +0100
Subject: [PATCH] BAEL-7092: How to get the size of a file in MB, KB & GB in
 java (#15117)

* BAEL-7092: How to get the size of a file in MB, KB & GB in java

* Update JavaFileSizeUnitTest.java

* BAEL-7092: How to get the size of a file in MB, KB & GB in java

---------

Co-authored-by: Grzegorz Piwowarek <gpiwowarek@gmail.com>
---
 .../java/com/baeldung/size/FileSizeUtils.java | 28 +++++++++++++++++
 .../baeldung/size/JavaFileSizeUnitTest.java   | 31 ++++++++++++++++---
 2 files changed, 54 insertions(+), 5 deletions(-)
 create mode 100644 core-java-modules/core-java-io/src/main/java/com/baeldung/size/FileSizeUtils.java

diff --git a/core-java-modules/core-java-io/src/main/java/com/baeldung/size/FileSizeUtils.java b/core-java-modules/core-java-io/src/main/java/com/baeldung/size/FileSizeUtils.java
new file mode 100644
index 0000000000..18c8687043
--- /dev/null
+++ b/core-java-modules/core-java-io/src/main/java/com/baeldung/size/FileSizeUtils.java
@@ -0,0 +1,28 @@
+package com.baeldung.size;
+
+import java.io.File;
+
+public class FileSizeUtils {
+    public static long getFileSizeInBytes(File file) {
+        if (file.exists()) {
+            return file.length();
+        } else {
+            throw new IllegalArgumentException("File not found.");
+        }
+    }
+
+    public static double getFileSizeInKilobytes(File file) {
+        long bytes = getFileSizeInBytes(file);
+        return (double) bytes / 1024;
+    }
+
+    public static double getFileSizeInMegabytes(File file) {
+        double kilobytes = getFileSizeInKilobytes(file);
+        return kilobytes / 1024;
+    }
+
+    public static double getFileSizeInGigabytes(File file) {
+        double megabytes = getFileSizeInMegabytes(file);
+        return megabytes / 1024;
+    }
+}
diff --git a/core-java-modules/core-java-io/src/test/java/com/baeldung/size/JavaFileSizeUnitTest.java b/core-java-modules/core-java-io/src/test/java/com/baeldung/size/JavaFileSizeUnitTest.java
index d015f2602e..d8f4361260 100644
--- a/core-java-modules/core-java-io/src/test/java/com/baeldung/size/JavaFileSizeUnitTest.java
+++ b/core-java-modules/core-java-io/src/test/java/com/baeldung/size/JavaFileSizeUnitTest.java
@@ -1,6 +1,8 @@
 package com.baeldung.size;
 
-import static org.junit.Assert.assertEquals;
+import org.apache.commons.io.FileUtils;
+import org.junit.Before;
+import org.junit.Test;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -10,9 +12,9 @@ import java.net.URL;
 import java.nio.channels.FileChannel;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import org.apache.commons.io.FileUtils;
-import org.junit.Before;
-import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
 
 public class JavaFileSizeUnitTest {
     private static final long EXPECTED_FILE_SIZE_IN_BYTES = 11;
@@ -85,4 +87,23 @@ public class JavaFileSizeUnitTest {
             assertEquals(EXPECTED_FILE_SIZE_IN_BYTES, stream.available());
         }
     }
-}
\ No newline at end of file
+
+    @Test
+    public void whenGetFileSizeInDifferentUnits_thenCorrect(){
+        filePath = String.join(File.separator, new String[] { "src", "test", "resources", "size", "sample_file_1.in" });
+        File file = new File(filePath);
+        if (file.exists()) {
+            long expectedBytes = file.length();
+            double expectedKilobytes = (double) expectedBytes / 1024;
+            double expectedMegabytes = expectedKilobytes / 1024;
+            double expectedGigabytes = expectedMegabytes / 1024;
+
+            assertEquals(expectedBytes, FileSizeUtils.getFileSizeInBytes(file));
+            assertEquals(expectedKilobytes, FileSizeUtils.getFileSizeInKilobytes(file), 0.01);
+            assertEquals(expectedMegabytes, FileSizeUtils.getFileSizeInMegabytes(file), 0.01);
+            assertEquals(expectedGigabytes, FileSizeUtils.getFileSizeInGigabytes(file), 0.01);
+        } else {
+            fail("File not found.");
+        }
+    }
+}