fixed typo in checksumhelper

Mage.Updater/src/main/java/com/magefree/update/helpers/ChecksumHelper.java

@@ -0,0 +1,49 @@
+package com.magefree.update.helpers;
+
+import java.io.FileInputStream;
+import java.io.InputStream;
+import java.security.MessageDigest;
+
+/**
+ * @author Loki
+ */
+public final class ChecksumHelper {
+
+    public static byte[] createChecksum(String filename) throws Exception {
+        InputStream fis = null;
+        MessageDigest complete;
+
+        try {
+            fis = new FileInputStream(filename);
+
+            byte[] buffer = new byte[1024];
+            complete = MessageDigest.getInstance("SHA1");
+
+            int numRead;
+            do {
+                numRead = fis.read(buffer);
+                if (numRead > 0) {
+                    complete.update(buffer, 0, numRead);
+                }
+            } while (numRead != -1);
+
+            return complete.digest();
+        } finally {
+            if (fis != null) {
+                fis.close();
+            }
+        }
+    }
+
+    // see this How-to for a faster way to convert
+    // a byte array to a HEX string
+    public static String getSHA1Checksum(String filename) throws Exception {
+        byte[] b = createChecksum(filename);
+        String result = "";
+        for (int i = 0; i < b.length; i++) {
+            result +=
+                    Integer.toString((b[i] & 0xff) + 0x100, 16).substring(1);
+        }
+        return result;
+    }
+}