Failed to load Main-Class manifest attribute

[David Scott]

pdfbox

When I try to execute this pdf to text extraction command:
java -jar /usr/share/java/pdfbox-1.7.1.jar ExtractText -startpage12 
-endpage33 Days.pdf days10.txt

I get:
Failed to load Main-Class manifest attribute from 
/usr/share/java/pdfbox-1.7.1.jar

My knowledge of java is zero.

Can someone tell me what I need to do to use the program?

Thanks,
David Scott