From 3178d8cb59093b173301389f906a47295dcd73d2 Mon Sep 17 00:00:00 2001
From: Michael Olayemi <michaelolayemi28@gmail.com>
Date: Thu, 19 Oct 2023 12:15:54 +0000
Subject: [PATCH] Get file size efficiently in Java (#14970)

* Get file size efficiently in Java

* Get file size efficiently in Java

* Get file size efficiently in Java

* Update FileSizeBenchmark.java
---
 .../sizebenchmark/FileSizeBenchmark.java      | 67 +++++++++++++++++++
 .../baeldung/size/JavaFileSizeUnitTest.java   | 23 +++++++
 2 files changed, 90 insertions(+)
 create mode 100644 core-java-modules/core-java-io/src/main/java/com/baeldung/sizebenchmark/FileSizeBenchmark.java

diff --git a/core-java-modules/core-java-io/src/main/java/com/baeldung/sizebenchmark/FileSizeBenchmark.java b/core-java-modules/core-java-io/src/main/java/com/baeldung/sizebenchmark/FileSizeBenchmark.java
new file mode 100644
index 0000000000..5998b0be73
--- /dev/null
+++ b/core-java-modules/core-java-io/src/main/java/com/baeldung/sizebenchmark/FileSizeBenchmark.java
@@ -0,0 +1,67 @@
+package com.baeldung.sizebenchmark;
+
+import org.apache.commons.io.FileUtils;
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.infra.Blackhole;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.channels.FileChannel;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.SingleShotTime)
+@OutputTimeUnit(TimeUnit.MILLISECONDS)
+@Warmup(iterations = 3, time = 10, timeUnit = TimeUnit.NANOSECONDS)
+@Measurement(iterations = 3, time = 10, timeUnit = TimeUnit.NANOSECONDS)
+public class FileSizeBenchmark {
+    
+    public static void main(String[] args) throws Exception {
+        org.openjdk.jmh.Main.main(args);
+    }
+
+    @Benchmark
+    public void getFileSizeUsingLengthMethod(Blackhole blackhole) throws Exception {
+        File file = new File("src/test/resources/size/sample_file_1.in");
+        blackhole.consume(file.length());
+    }
+
+    @Benchmark
+    public void getFileSizeUsingFileInputStream(Blackhole blackhole) throws Exception {
+        try (FileInputStream fis = new FileInputStream("src/test/resources/size/sample_file_1.in")) {
+            long result = fis.getChannel().size();
+            blackhole.consume(result);
+        }
+
+    }
+
+    @Benchmark
+    public void getFileSizeUsingInputStreamAndUrl(Blackhole blackhole) throws Exception {
+        File me = new File("src/test/resources/size/sample_file_1.in");
+        URL url = me.toURI().toURL();
+
+        try (InputStream stream = url.openStream()) {
+            blackhole.consume(stream.available());
+        }
+    }
+
+    @Benchmark
+    public void getFileSizeUsingApacheCommon(Blackhole blackhole) {
+        File imageFile = new File("src/test/resources/size/sample_file_1.in");
+        long size = FileUtils.sizeOf(imageFile);
+        blackhole.consume(size);
+    }
+
+    @Benchmark
+    public void getFileSizeUsingFileChannel(Blackhole blackhole) throws IOException {
+        Path imageFilePath = Paths.get("src/test/resources/size/sample_file_1.in");
+        try (FileChannel imageFileChannel = FileChannel.open(imageFilePath)) {
+            long imageFileSize = imageFileChannel.size();
+            blackhole.consume(imageFileSize);
+        }
+    }
+}
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 6b6197c7ce..d015f2602e 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
@@ -3,7 +3,10 @@ package com.baeldung.size;
 import static org.junit.Assert.assertEquals;
 
 import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
 import java.nio.channels.FileChannel;
 import java.nio.file.Path;
 import java.nio.file.Paths;
@@ -62,4 +65,24 @@ public class JavaFileSizeUnitTest {
         final long length = file.length();
         return length;
     }
+
+    @Test
+    public void whenGetFileSizeUsingFileInputStream_thenCorrect() throws IOException {
+
+        try (FileInputStream fis = new FileInputStream(filePath)) {
+            long result = fis.getChannel().size();
+            assertEquals(EXPECTED_FILE_SIZE_IN_BYTES, result);
+        }
+    }
+
+    @Test
+    public void whenGetFileSizeUsingUrlAndInputStream_thenCorrect() throws IOException {
+
+        File file = new File(filePath);
+        URL url = file.toURI().toURL();
+
+        try (InputStream stream = url.openStream()) {
+            assertEquals(EXPECTED_FILE_SIZE_IN_BYTES, stream.available());
+        }
+    }
 }
\ No newline at end of file