Problem with file .jar

 When i run project in netbeans it prints in pdf with ireport. When i biuld project and generate .jar it doesnt print. Why? 

ps. When running output is:

log4j:WARN No appenders could be found for logger (net.sf.jasperreports.extensions.ExtensionsEnvironment).

log4j:WARN Please initialize the log4j system properly.

Sorry for my english.