Add RandomAccessFile digest methods

src/main/java/org/apache/commons/codec/digest/DigestUtils.java

@@ -20,9 +20,11 @@
 import java.io.BufferedInputStream;
 import java.io.File;
 import java.io.FileInputStream;
+import java.io.RandomAccessFile;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
@@ -99,6 +101,20 @@ public static byte[] digest(final MessageDigest messageDigest, final File data)
         return updateDigest(messageDigest, data).digest();
     }
 
+    /**
+     * Reads through a RandomAccessFile using non-blocking-io (NIO) and returns the digest for the data
+     *
+     * @param messageDigest The MessageDigest to use (e.g. MD5)
+     * @param data          Data to digest
+     * @return the digest
+     * @throws IOException On error reading from the stream
+     * @since 1.14
+     */
+    public static byte[] digest(final MessageDigest messageDigest, final RandomAccessFile data) throws IOException {
+        data.seek(0);
+        return updateDigest(messageDigest, data).digest();
+    }
+
     /**
      * Reads through an InputStream and returns the digest for the data
      *
@@ -1207,6 +1223,29 @@ public static MessageDigest updateDigest(final MessageDigest digest, final File
         }
     }
 
+    /**
+     * Reads through a RandomAccessFile and updates the digest for the data
+     * using non-blocking-io (NIO)
+     *
+     * @param digest The MessageDigest to use (e.g. MD5)
+     * @param data   Data to digest
+     * @return the digest
+     * @throws IOException On error reading from the stream
+     * @since 1.14
+     */
+    public static MessageDigest updateDigest(final MessageDigest digest, final RandomAccessFile data) throws IOException {
+        final FileChannel channel = data.getChannel();
+        final ByteBuffer buffer = ByteBuffer.allocate(STREAM_BUFFER_LENGTH);
+
+        while (channel.read(buffer) > 0) {
+            buffer.flip();
+            digest.update(buffer);
+            buffer.clear();
+        }
+
+        return digest;
+    }
+
     /**
      * Reads through an InputStream and updates the digest for the data
      *

src/test/java/org/apache/commons/codec/digest/DigestUtilsTest.java

@@ -24,6 +24,7 @@
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.RandomAccessFile;
 import java.nio.ByteBuffer;
 import java.security.MessageDigest;
 import java.util.Random;
@@ -47,6 +48,10 @@ public class DigestUtilsTest {
 
     private File testFile;
 
+    private File testRandomAccessFile;
+
+    private RandomAccessFile testRandomAccessFileWrapper;
+
     private void assumeJava8() {
         Assume.assumeTrue(SystemUtils.isJavaVersionAtLeast(JavaVersion.JAVA_1_8));
     }
@@ -63,20 +68,34 @@ File getTestFile() {
         return testFile;
     }
 
+    RandomAccessFile getTestRandomAccessFile() {
+        return testRandomAccessFileWrapper;
+    }
+
     @Before
     public void setUp() throws Exception {
         new Random().nextBytes(testData);
         testFile = File.createTempFile(DigestUtilsTest.class.getName(), ".dat");
         try (final FileOutputStream fos = new FileOutputStream(testFile)) {
             fos.write(testData);
         }
+
+        testRandomAccessFile = File.createTempFile(DigestUtilsTest.class.getName(), ".dat");
+        try (final FileOutputStream fos = new FileOutputStream(testRandomAccessFile)) {
+            fos.write(testData);
+        }
+        testRandomAccessFileWrapper = new RandomAccessFile(testRandomAccessFile, "rw");
     }
 
     @After
     public void tearDown() {
         if (!testFile.delete()) {
             testFile.deleteOnExit();
         }
+
+        if (!testRandomAccessFile.delete()) {
+            testRandomAccessFile.deleteOnExit();
+        }
     }
 
     @Test(expected=IllegalArgumentException.class)

src/test/java/org/apache/commons/codec/digest/MessageDigestAlgorithmsTest.java

@@ -19,6 +19,7 @@
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.IOException;
+import java.io.RandomAccessFile;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.nio.ByteBuffer;
@@ -106,6 +107,10 @@ private File getTestFile() {
         return digestUtilsTest.getTestFile();
     }
 
+    private RandomAccessFile getTestRandomAccessFile() {
+        return digestUtilsTest.getTestRandomAccessFile();
+    }
+
     @Before
     public void setUp() throws Exception {
         digestUtilsTest = new DigestUtilsTest();
@@ -151,6 +156,25 @@ public void testDigestFile() throws IOException {
         Assert.assertArrayEquals(digestTestData(), DigestUtils.digest(DigestUtils.getDigest(messageDigestAlgorithm),getTestFile()));
     }
 
+    @Test
+    public void testNonBlockingDigestRandomAccessFile() throws IOException {
+        Assume.assumeTrue(DigestUtils.isAvailable(messageDigestAlgorithm));
+
+        final byte[] expected = digestTestData();
+
+        Assert.assertArrayEquals(expected,
+                DigestUtils.digest(
+                        DigestUtils.getDigest(messageDigestAlgorithm), getTestRandomAccessFile()
+                )
+        );
+
+        Assert.assertArrayEquals(expected,
+                DigestUtils.digest(
+                        DigestUtils.getDigest(messageDigestAlgorithm), getTestRandomAccessFile()
+                )
+        );
+    }
+
     @Test
     public void testDigestInputStream() throws IOException {
         Assume.assumeTrue(DigestUtils.isAvailable(messageDigestAlgorithm));