From effde80333489fa4b74cb173261c812456de8134 Mon Sep 17 00:00:00 2001
From: Anshul Bansal <smartdiscover17@gmail.com>
Date: Wed, 23 Jan 2019 14:19:48 +0200
Subject: [PATCH] BAEL - 2420 Converting Float to Byte Array and vice-versa in
 Java (#6194)

* Hexagonal Architecture in Java - Spring boot app

* create README.md

* Update README.md

* Update README.md

* BAEL-2420 Converting Float to Byte Array and vice-versa in Java

* BAEL-2420 Converting Float to Byte Array and vice-versa in Java - conversions package added

* Hexagonal architecture code removed
---
 .../array/conversions/FloatToByteArray.java   | 44 ++++++++++++++++++
 .../conversions/FloatToByteArrayUnitTest.java | 46 +++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 core-java-arrays/src/main/java/com/baeldung/array/conversions/FloatToByteArray.java
 create mode 100644 core-java-arrays/src/test/java/com/baeldung/array/conversions/FloatToByteArrayUnitTest.java

diff --git a/core-java-arrays/src/main/java/com/baeldung/array/conversions/FloatToByteArray.java b/core-java-arrays/src/main/java/com/baeldung/array/conversions/FloatToByteArray.java
new file mode 100644
index 0000000000..b831e436a5
--- /dev/null
+++ b/core-java-arrays/src/main/java/com/baeldung/array/conversions/FloatToByteArray.java
@@ -0,0 +1,44 @@
+package com.baeldung.array.conversions;
+
+import java.nio.ByteBuffer;
+
+public class FloatToByteArray {
+    
+    /**
+     * convert float into byte array using Float API floatToIntBits 
+     * @param value
+     * @return byte[]
+     */
+    public static byte[] floatToByteArray(float value) {
+        int intBits =  Float.floatToIntBits(value);
+        return new byte[] {(byte) (intBits >> 24), (byte) (intBits >> 16), (byte) (intBits >> 8), (byte) (intBits) };
+    }
+    
+    /**
+     * convert byte array into float using Float API intBitsToFloat
+     * @param bytes
+     * @return float
+     */
+    public static float byteArrayToFloat(byte[] bytes) {
+        int intBits =  bytes[0] << 24 | (bytes[1] & 0xFF) << 16 | (bytes[2] & 0xFF) << 8 | (bytes[3] & 0xFF);
+        return Float.intBitsToFloat(intBits);
+    }
+    
+    /**
+     * convert float into byte array using ByteBuffer
+     * @param value
+     * @return byte[]
+     */
+    public static byte[] floatToByteArrayWithByteBuffer(float value) {
+        return ByteBuffer.allocate(4).putFloat(value).array();
+    }
+    
+    /**
+     * convert byte array into float using ByteBuffer
+     * @param bytes
+     * @return float
+     */
+    public static float byteArrayToFloatWithByteBuffer(byte[] bytes) {
+        return ByteBuffer.wrap(bytes).getFloat();
+    }
+}
diff --git a/core-java-arrays/src/test/java/com/baeldung/array/conversions/FloatToByteArrayUnitTest.java b/core-java-arrays/src/test/java/com/baeldung/array/conversions/FloatToByteArrayUnitTest.java
new file mode 100644
index 0000000000..a2cd273f21
--- /dev/null
+++ b/core-java-arrays/src/test/java/com/baeldung/array/conversions/FloatToByteArrayUnitTest.java
@@ -0,0 +1,46 @@
+package com.baeldung.array.conversions;
+
+import static com.baeldung.array.conversions.FloatToByteArray.byteArrayToFloat;
+import static com.baeldung.array.conversions.FloatToByteArray.byteArrayToFloatWithByteBuffer;
+import static com.baeldung.array.conversions.FloatToByteArray.floatToByteArray;
+import static com.baeldung.array.conversions.FloatToByteArray.floatToByteArrayWithByteBuffer;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import org.junit.Test;
+
+public class FloatToByteArrayUnitTest {
+
+    @Test
+    public void givenAFloat_thenConvertToByteArray() {
+        assertArrayEquals(new byte[] { 63, -116, -52, -51}, floatToByteArray(1.1f));
+    }
+
+    @Test
+    public void givenAByteArray_thenConvertToFloat() {
+        assertEquals(1.1f, byteArrayToFloat(new byte[] { 63, -116, -52, -51}), 0);
+    }
+
+    @Test
+    public void givenAFloat_thenConvertToByteArrayUsingByteBuffer() {
+        assertArrayEquals(new byte[] { 63, -116, -52, -51}, floatToByteArrayWithByteBuffer(1.1f));
+    }
+
+    @Test
+    public void givenAByteArray_thenConvertToFloatUsingByteBuffer() {
+        assertEquals(1.1f, byteArrayToFloatWithByteBuffer(new byte[] { 63, -116, -52, -51}), 0);
+    }
+
+    @Test
+    public void givenAFloat_thenConvertToByteArray_thenConvertToFloat() {
+        float floatToConvert = 200.12f;
+        byte[] byteArray = floatToByteArray(floatToConvert);
+        assertEquals(200.12f, byteArrayToFloat(byteArray), 0);
+    }
+    
+    @Test
+    public void givenAFloat_thenConvertToByteArrayWithByteBuffer_thenConvertToFloatWithByteBuffer() {
+        float floatToConvert = 30100.42f;
+        byte[] byteArray = floatToByteArrayWithByteBuffer(floatToConvert);
+        assertEquals(30100.42f, byteArrayToFloatWithByteBuffer(byteArray), 0);
+    }
+}