BAEL-2509

* New section in InputStream to byte array article and recreating branch.

* Minor typo

* Code reformat using intellij formatter.

* Code reformat using intellij formatter.

* guava implementation to be completed

* guava implementation

* Added assert to guava test

* Fix formatting

* Formatting using Baeldung format

* Based on Josh comments, I removed some code BAEL-2509

* Removed all references to File

* Update fork from upstream

* Update fork from upstream

* Merhe Upstream

* Remove all references to FileInputStream (Josh Comments)

* Delete CustomBaeldungQueueUnitTest.java

core-java-io/src/test/java/org/baeldung/java/io/InputStreamToByteBufferUnitTest.java

@@ -1,60 +1,56 @@
 package org.baeldung.java.io;
 
-
+import com.google.common.io.ByteSource;
 import com.google.common.io.ByteStreams;
 import org.apache.commons.io.IOUtils;
-import org.junit.jupiter.api.Test;
+import org.junit.Test;
 
-import java.io.File;
-import java.io.FileInputStream;
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static java.nio.channels.Channels.newChannel;
+import static org.junit.Assert.assertEquals;
 
-class InputStreamToByteBufferUnitTest {
+public class InputStreamToByteBufferUnitTest {
 
     @Test
-    public void givenUsingCoreClasses_whenWritingAFileIntoAByteBuffer_thenBytesLengthMustMatch() throws IOException {
-        File inputFile = getFile();
-        ByteBuffer bufferByte = ByteBuffer.allocate((int) inputFile.length());
-        FileInputStream in = new FileInputStream(inputFile);
-        in.getChannel().read(bufferByte);
+    public void givenUsingCoreClasses_whenByteArrayInputStreamToAByteBuffer_thenLengthMustMatch() throws IOException {
+        byte[] input = new byte[] { 0, 1, 2 };
+        InputStream initialStream = new ByteArrayInputStream(input);
+        ByteBuffer byteBuffer = ByteBuffer.allocate(3);
+        while (initialStream.available() > 0) {
+            byteBuffer.put((byte) initialStream.read());
+        }
 
-        assertEquals(bufferByte.position(), inputFile.length());
+        assertEquals(byteBuffer.position(), input.length);
     }
 
     @Test
-    public void givenUsingCommonsIo_whenWritingAFileIntoAByteBuffer_thenBytesLengthMustMatch() throws IOException {
-        File inputFile = getFile();
-        ByteBuffer bufferByte = ByteBuffer.allocateDirect((int) inputFile.length());
-        ReadableByteChannel readableByteChannel = new FileInputStream(inputFile).getChannel();
-        IOUtils.readFully(readableByteChannel, bufferByte);
-
-        assertEquals(bufferByte.position(), inputFile.length());
-    }
-
-    @Test
-    public void givenUsingGuava_whenWritingAFileIntoAByteBuffer_thenBytesLengthMustMatch() throws IOException {
-        File inputFile = getFile();
-        FileInputStream in = new FileInputStream(inputFile);
-        byte[] targetArray = ByteStreams.toByteArray(in);
+    public void givenUsingGuava__whenByteArrayInputStreamToAByteBuffer_thenLengthMustMatch() throws IOException {
+        InputStream initialStream = ByteSource
+          .wrap(new byte[] { 0, 1, 2 })
+          .openStream();
+        byte[] targetArray = ByteStreams.toByteArray(initialStream);
         ByteBuffer bufferByte = ByteBuffer.wrap(targetArray);
-        bufferByte.rewind();
         while (bufferByte.hasRemaining()) {
             bufferByte.get();
         }
-        
-        assertEquals(bufferByte.position(), inputFile.length());
+
+        assertEquals(bufferByte.position(), targetArray.length);
     }
 
-    private File getFile() {
-        ClassLoader classLoader = new InputStreamToByteBufferUnitTest().getClass().getClassLoader();
+    @Test
+    public void givenUsingCommonsIo_whenByteArrayInputStreamToAByteBuffer_thenLengthMustMatch() throws IOException {
+        byte[] input = new byte[] { 0, 1, 2 };
+        InputStream initialStream = new ByteArrayInputStream(input);
+        ByteBuffer byteBuffer = ByteBuffer.allocate(3);
+        ReadableByteChannel channel = newChannel(initialStream);
+        IOUtils.readFully(channel, byteBuffer);
 
-        String fileName = "frontenac-2257154_960_720.jpg";
-
-        return new File(classLoader.getResource(fileName).getFile());
+        assertEquals(byteBuffer.position(), input.length);
     }
 
 }