how run ireport v5.6.0 o JasperReports in GNU/LINUX jdk 7

first install jdk7 in your system

sudo apt-get install jdk7-openjdk

download ireport
 https://community.jaspersoft.com/project/jasperreports-library/releases

now you run with jdk7

./ireport --jdkhome "/usr/lib/jvm/java-7-jdk/"

it is all :)