PDFBOX-5660: fix javadoc as suggested by Valery Bokov; fix field name; closes #379

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1930529 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/interactive/digitalsignature/PDSeedValueTimeStamp.java

@@ -20,8 +20,8 @@
 import org.apache.pdfbox.cos.COSName;
 
 /**
- * If exist, it describe where the signature handler can request a RFC3161
- * timestamp and if it is a must have for the signature.
+ * This optional dictionary provides the URL for a RFC3161 time-stamping server server, and whether
+ * the timestamp is required for the signature.
  *
  * @author Thomas Chojecki
  */
@@ -85,7 +85,7 @@ public void setURL(String url)
      */
     public boolean isTimestampRequired()
     {
-        return dictionary.getInt(COSName.FT, 0) != 0;
+        return dictionary.getInt(COSName.FF, 0) != 0;
     }
 
     /**
@@ -95,6 +95,6 @@ public boolean isTimestampRequired()
      */
     public void setTimestampRequired(boolean flag)
     {
-        dictionary.setInt(COSName.FT, flag ? 1 : 0);
+        dictionary.setInt(COSName.FF, flag ? 1 : 0);
     }
 }