added some catch clauses to ensure the batch is processed :-)

mustang/toecount/pom.xml

@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.mustangproject.ZUGFeRD</groupId>
 	<artifactId>toecount</artifactId>
-	<version>0.0.6-SNAPSHOT</version>
+	<version>0.0.7-SNAPSHOT</version>
 	<name>ZUGFeRD PDF checker</name>
 	<description>Shows statistics on how many PDFs in a directory are ZUGFeRD-Compliant</description>
 	<repositories>

mustang/toecount/src/main/java/toecount/FileChecker.java

@@ -30,6 +30,7 @@ public class FileChecker {
 			return false;
 		}
 		ZUGFeRDImporter zi=new ZUGFeRDImporter();
+		try {
 			zi.extract(filename);
 			if (zi.canParse()) {
 				thisRun.incZUGFeRDCount();
@@ -37,6 +38,28 @@ public class FileChecker {
 			} else {
 				return false;
 			}
+		} catch (NullPointerException e) {
+			// something really rare happened -- corrupted ZF?
+			/***
+			 * e.g. Exception in thread "main" java.lang.NullPointerException
+        at org.mustangproject.ZUGFeRD.ZUGFeRDImporter.extractLowLevel(ZUGFeRDImporter.java:90)
+        at org.mustangproject.ZUGFeRD.ZUGFeRDImporter.extract(ZUGFeRDImporter.java:64)
+        at toecount.FileChecker.checkForZUGFeRD(FileChecker.java:33)
+        at toecount.Toecount.main(Toecount.java:111)
+			 * 
+			 */
+			// Ignore nevertheless, most likely we're batch processing
+			return false;
+		} catch (Exception e2) {
+			/**
+			 * probably thrown up from 
+			AM org.apache.pdfbox.pdfparser.PDFParser parse, most likely
+			INFORMATION: Document is encrypted
+			but also other internal PDF errors possible like 
+			..Okt 23, 2015 11:17:53 AM org.apache.pdfbox.pdfparser.XrefTrailerResolver setStartxref
+			 */
+			return false;
+		}
 	}
 	
 	public boolean isPDF() {

mustang/toecount/src/main/java/toecount/Toecount.java

@@ -22,7 +22,7 @@ public class Toecount {
 	}
 	private static void printHelp() {
 		System.out
-		.println("Mustangproject.org's Toecount 0.0.6 \r\n"
+		.println("Mustangproject.org's Toecount 0.0.7 \r\n"
 				+ "A Apache Public License command line tool for statistics on PDF invoices with\r\n"
 				+ "ZUGFeRD Metadata (http://www.zugferd.de)\r\n"
 				+ "\r\n"