create a variable In subreport say returnValue
variable class type --> whatever u want
calculation type --> nothing
reset type and increment type -->none
variable expression --> value you want to return
In main report create variable with same name as returnValue
variable class type --> same as return type
calculation type --> nothing
reset type and increment type -->none
variable expression --> blank
In main report Subreport --> properties -->Subreport(other)-->subreport return values-->add
Subreport variable--> variable name as returnValue(u want to return)
local destination variable --> main report variable (returnValue)
calculation type --> nothing
and use that variable wherever u want .
10_jasper return value from the subreport to main report
原文：http://www.cnblogs.com/liupuLearning/p/6062350.html