days function does not work when integrate with web java code

[wangmin2001]

HI, I am using jasper5.6.1 in win7,jdk1.7, I use days function in studio to calculate date diff between min_date and max_date, such as :

days($V{min_date},$V{max_date})

it works fine in studio, but when I called it from web java application, it always return me following error:

net.sf.jasperreports.engine.fill.JRExpressionEvalException: Error evaluating expression :
    Source text : DAYS($V{min_date},$V{max_date})

I also encountered another IF experession error,

 

I doubt it's java issue, and I check my report language setting, it's "JAVA".

if I cannnot use system function, I have to pass all calculated varibles from outside application, it's too complex.

could you give me some suggesiton? thanks!

 

 

[wangmin2001]

I have to add my update info:

I  I changed report language to groovy from java, and add groovy class into classpath, now it return me :

net.sf.jasperreports.engine.fill.JRExpressionEvalException: Error evaluating expression :
    Source text : ABS($F{QUANTITY})

it seems that I canno use any build-in fuctions in japer studio, inlcude:  IF-else, ABS, Days.

I found it's becuase there is no jasper mathfuction class. I search all folder, found there have classes at sample folder, I add them, then pass!

conclusion: I do not know why jasper do no package mathfunction into jasper lib, but, if you want to use it, you have to include it mannualy.