opening IReport getting error message - "Cannot find java exe."

This is because jdkhome is not setup yet or jdkhome cannot locate your jdk file in the system. all you have to do is:

-setup jdkhome in ireport's ireport.conf file

jdkhome="/path/to/jdk"
jdkhome="c:Program Files/Java/jre7"-file to jdk

You will have to locate your IReport's ireport.conf file and edit it

Open it then change the line jdkhome="/path/to/jdk"

(i.e. jdkhome="c:Program Files/Java/jre7" - where your jdk / jre (version) file is located)

First of all iReports 5.6.0 will work on jdk 1.7.x.x it will not work on jdk 1.8.x.x therefore first you will have to install jdk 1.7.x.x

Then goto the folder where the jasperreport is installed. eg:C:\Program Files (x86)\Jaspersoft\iReport-5.6.0\etc then edit the "ireport.conf" file.

edit the file with notepad and change the following line to this.

jdkhome="/path/to/jdk" to jdkhome="C:\Program Files\Java\jdk x.x"

Indicate the version of your installed JDK and also make sure to remove the "#" symbol or it will not work