Add and use IOUtils.byteArray(*).

Author: Gary Gregory

src/changes/changes.xml

@@ -166,6 +166,9 @@ The <action> type attribute can be add,update,fix,remove.
       <action  issue="IO-706" dev="ggregory" type="add" due-to="Gary Gregory">
         Add TimetampedObserver.
       </action>
+      <action dev="ggregory" type="add" due-to="Gary Gregory">
+        Add and use IOUtils.byteArray(*).
+      </action>
       <!-- UPDATES -->
       <action dev="ggregory" type="update" due-to="Dependabot">
         Update junit-jupiter from 5.6.2 to 5.7.0 #153.

src/main/java/org/apache/commons/io/ByteOrderMark.java

@@ -122,7 +122,7 @@ public int get(final int pos) {
      * @return a copy of the BOM's bytes
      */
     public byte[] getBytes() {
-        final byte[] copy = new byte[bytes.length];
+        final byte[] copy = IOUtils.byteArray(bytes.length);
         for (int i = 0; i < bytes.length; i++) {
             copy[i] = (byte)bytes[i];
         }

src/main/java/org/apache/commons/io/CopyUtils.java

@@ -113,11 +113,6 @@
 @Deprecated
 public class CopyUtils {
 
-    /**
-     * The default size of the buffer.
-     */
-    private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
-
     /**
      * Instances should NOT be constructed in standard programming.
      */
@@ -172,7 +167,7 @@ public static void copy(final byte[] input, final Writer output, final String en
      * @throws IOException In case of an I/O problem
      */
     public static int copy(final InputStream input, final OutputStream output) throws IOException {
-        final byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
+        final byte[] buffer = IOUtils.byteArray();
         int count = 0;
         int n = 0;
         while (EOF != (n = input.read(buffer))) {
@@ -197,7 +192,7 @@ public static int copy(
             final Reader input,
             final Writer output)
                 throws IOException {
-        final char[] buffer = new char[DEFAULT_BUFFER_SIZE];
+        final char[] buffer = new char[IOUtils.DEFAULT_BUFFER_SIZE];
         int count = 0;
         int n = 0;
         while (EOF != (n = input.read(buffer))) {

src/main/java/org/apache/commons/io/IOUtils.java

@@ -172,7 +172,7 @@ public class IOUtils {
     /**
      * The default buffer to use for the skip() methods.
      */
-    private static final byte[] SKIP_BYTE_BUFFER = new byte[DEFAULT_BUFFER_SIZE];
+    private static final byte[] SKIP_BYTE_BUFFER = byteArray();
 
     // Allocated in the relevant skip method if necessary.
     /*
@@ -315,6 +315,29 @@ public static BufferedWriter buffer(final Writer writer, final int size) {
         return writer instanceof BufferedWriter ? (BufferedWriter) writer : new BufferedWriter(writer, size);
     }
 
+    /**
+     * Returns a new byte array of size {@link #DEFAULT_BUFFER_SIZE}.
+     *
+     * @return a new byte array of size {@link #DEFAULT_BUFFER_SIZE}.
+     * @since 2.9.0
+     */
+    public static byte[] byteArray() {
+        return byteArray(DEFAULT_BUFFER_SIZE);
+    }
+
+    /**
+     * Returns a new byte array of the given size.
+     *
+     * TODO Consider guarding or warning against large allocations...
+     *
+     * @param size array size.
+     * @return a new byte array of the given size.
+     * @since 2.9.0
+     */
+    public static byte[] byteArray(final int size) {
+        return new byte[size];
+    }
+
     /**
      * Closes the given {@link Closeable} as a null-safe operation.
      *
@@ -754,8 +777,8 @@ public static boolean contentEquals(final InputStream input1, final InputStream
             return false;
         }
 
-        final byte[] array1 = new byte[DEFAULT_BUFFER_SIZE];
-        final byte[] array2 = new byte[DEFAULT_BUFFER_SIZE];
+        final byte[] array1 = byteArray();
+        final byte[] array2 = byteArray();
         int pos1;
         int pos2;
         int count1;
@@ -925,7 +948,7 @@ public static int copy(final InputStream inputStream, final OutputStream outputS
      */
     public static long copy(final InputStream inputStream, final OutputStream outputStream, final int bufferSize)
             throws IOException {
-        return copyLarge(inputStream, outputStream, new byte[bufferSize]);
+        return copyLarge(inputStream, outputStream, IOUtils.byteArray(bufferSize));
     }
 
     /**
@@ -1243,7 +1266,7 @@ public static long copyLarge(final InputStream inputStream, final OutputStream o
      */
     public static long copyLarge(final InputStream input, final OutputStream output, final long inputOffset,
                                  final long length) throws IOException {
-        return copyLarge(input, output, inputOffset, length, new byte[DEFAULT_BUFFER_SIZE]);
+        return copyLarge(input, output, inputOffset, length, byteArray());
     }
 
     /**
@@ -1730,7 +1753,7 @@ public static void readFully(final InputStream input, final byte[] buffer, final
      * @since 2.5
      */
     public static byte[] readFully(final InputStream input, final int length) throws IOException {
-        final byte[] buffer = new byte[length];
+        final byte[] buffer = IOUtils.byteArray(length);
         readFully(input, buffer, 0, buffer.length);
         return buffer;
     }
@@ -2317,7 +2340,7 @@ public static byte[] toByteArray(final InputStream input, final int size) throws
             return EMPTY_BYTE_ARRAY;
         }
 
-        final byte[] data = new byte[size];
+        final byte[] data = IOUtils.byteArray(size);
         int offset = 0;
         int read;
 

src/main/java/org/apache/commons/io/filefilter/MagicNumberFileFilter.java

@@ -29,6 +29,8 @@
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.Arrays;
 
+import org.apache.commons.io.IOUtils;
+
 /**
  * <p>
  * File filter for matching files containing a "magic number". A magic number
@@ -171,7 +173,7 @@ public MagicNumberFileFilter(final byte[] magicNumber, final long offset) {
             throw new IllegalArgumentException("The offset cannot be negative");
         }
 
-        this.magicNumbers = new byte[magicNumber.length];
+        this.magicNumbers = IOUtils.byteArray(magicNumber.length);
         System.arraycopy(magicNumber, 0, this.magicNumbers, 0, magicNumber.length);
         this.byteOffset = offset;
     }
@@ -258,7 +260,7 @@ public boolean accept(final File file) {
         if (file != null && file.isFile() && file.canRead()) {
             try {
                 try (RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r")) {
-                    final byte[] fileBytes = new byte[this.magicNumbers.length];
+                    final byte[] fileBytes = IOUtils.byteArray(this.magicNumbers.length);
                     randomAccessFile.seek(byteOffset);
                     final int read = randomAccessFile.read(fileBytes);
                     if (read != magicNumbers.length) {

src/main/java/org/apache/commons/io/input/ObservableInputStream.java

@@ -164,7 +164,7 @@ public void close() throws IOException {
      * @throws IOException The underlying {@link InputStream}, or either of the observers has thrown an exception.
      */
     public void consume() throws IOException {
-        final byte[] buffer = new byte[IOUtils.DEFAULT_BUFFER_SIZE];
+        final byte[] buffer = IOUtils.byteArray();
         while (read(buffer) != EOF) {
             // empty
         }

src/main/java/org/apache/commons/io/input/ReversedLinesFileReader.java

@@ -90,7 +90,7 @@ private void createLeftOver() {
             final int lineLengthBytes = currentLastBytePos + 1;
             if (lineLengthBytes > 0) {
                 // create left over for next block
-                leftOver = new byte[lineLengthBytes];
+                leftOver = IOUtils.byteArray(lineLengthBytes);
                 System.arraycopy(data, 0, leftOver, 0, lineLengthBytes);
             } else {
                 leftOver = null;
@@ -149,7 +149,7 @@ private String readLine() {
                     if (lineLengthBytes < 0) {
                         throw new IllegalStateException("Unexpected negative line length=" + lineLengthBytes);
                     }
-                    final byte[] lineData = new byte[lineLengthBytes];
+                    final byte[] lineData = IOUtils.byteArray(lineLengthBytes);
                     System.arraycopy(data, lineStart, lineData, 0, lineLengthBytes);
 
                     line = new String(lineData, charset);

src/main/java/org/apache/commons/io/input/Tailer.java

@@ -259,7 +259,7 @@ public Tailer(final File file, final Charset charset, final TailerListener liste
         this.delayMillis = delayMillis;
         this.end = end;
 
-        this.inbuf = new byte[bufSize];
+        this.inbuf = IOUtils.byteArray(bufSize);
 
         // Save and prepare the listener
         this.listener = listener;

src/main/java/org/apache/commons/io/input/XmlStreamReader.java

@@ -186,7 +186,7 @@ private static String getXmlProlog(final InputStream inputStream, final String g
             throws IOException {
         String encoding = null;
         if (guessedEnc != null) {
-            final byte[] bytes = new byte[IOUtils.DEFAULT_BUFFER_SIZE];
+            final byte[] bytes = IOUtils.byteArray();
             inputStream.mark(IOUtils.DEFAULT_BUFFER_SIZE);
             int offset = 0;
             int max = IOUtils.DEFAULT_BUFFER_SIZE;

src/main/java/org/apache/commons/io/input/buffer/CircularBufferInputStream.java

@@ -78,7 +78,7 @@ protected void fillBuffer() throws IOException {
             return;
         }
         int space = buffer.getSpace();
-        final byte[] buf = new byte[space];
+        final byte[] buf = IOUtils.byteArray(space);
         while (space > 0) {
             final int res = in.read(buf, 0, space);
             if (res == EOF) {