FileUtils: add method to read contents of a file

Author: ctrueden

src/main/java/org/scijava/util/FileUtils.java

@@ -34,6 +34,7 @@
 
 package org.scijava.util;
 
+import java.io.DataInputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FilenameFilter;
@@ -132,6 +133,24 @@ public static Date getModifiedTime(final File file) {
 		return c.getTime();
 	}
 
+	/**
+	 * Reads the contents of the given file into a new byte array.
+	 * 
+	 * @see DigestUtils#string(byte[]) To convert a byte array to a string.
+	 * @throws IOException If the file cannot be read.
+	 */
+	public static byte[] readFile(final File file) throws IOException {
+		final long length = file.length();
+		if (length > Integer.MAX_VALUE) {
+			throw new IllegalArgumentException("File too large");
+		}
+		final DataInputStream dis = new DataInputStream(new FileInputStream(file));
+		final byte[] bytes = new byte[(int) length];
+		dis.readFully(bytes);
+		dis.close();
+		return bytes;
+	}
+
 	/**
 	 * A regular expression to match filenames containing version information.
 	 * <p>