Add new empty() constructor

Author: patrickfav

CHANGELOG

@@ -5,6 +5,7 @@
  * add `encodeCharsetToBytes()` feature #7
  * add new `from(char[] charArray, Charset charset)` constructor with improved logic #8
  * add constructor/converter from/to UUID #9
+ * add `empty()` constructor, creating empty byte array
 
 ## v0.5.0
 

README.md

@@ -139,6 +139,7 @@ Initializing **empty arrays** of arbitrary length:
 ```java
 Bytes.allocate(16);
 Bytes.allocate(4, (byte) 1); //fill with 0x01
+Bytes.empty(); //creates zero length byte array
 ```
 
 Creating **random** byte arrays for e.g. testing:

src/main/java/at/favre/lib/bytes/Bytes.java

@@ -92,12 +92,21 @@ public static Bytes allocate(int length) {
      */
     public static Bytes allocate(int length, byte defaultValue) {
         byte[] array = new byte[length];
-        if (defaultValue != 0) {
+        if (defaultValue != 0 && length > 0) {
             Arrays.fill(array, defaultValue);
         }
         return wrap(array);
     }
 
+    /**
+     * Creates an Byte instance with an internal empty byte array. Same as calling {@link #allocate(int)} with 0.
+     *
+     * @return new instance
+     */
+    public static Bytes empty() {
+        return allocate(0);
+    }
+
     /**
      * Creates a new reference backed by the same byte array.
      * Inherits all attributes (readonly, etc.)

src/test/java/at/favre/lib/bytes/BytesConstructorTests.java

@@ -76,6 +76,13 @@ public void wrapTestNullSafe() {
         Bytes.wrapNullSafe(null);
     }
 
+    @Test
+    public void empty() {
+        assertEquals(0, Bytes.empty().length());
+        assertEquals(Bytes.allocate(0), Bytes.empty());
+        assertArrayEquals(new byte[0], Bytes.empty().array());
+    }
+
     @Test
     public void allocate() {
         assertEquals(0, Bytes.allocate(0).length());