How to find sum of column in Ireport or jasper report?-Collection of common programming errors

I had a fields of Integer type and was trying to add the columns . I was not getting any error when the report is previewed but my java application was failing to compile the report and giving the error as

The operator + is undefined for the argument type(s) java.lang.Integer, java.lang.Integer value = (java.lang.Integer)(((java.lang.Integer)field_nBSRptSchm1Col1.getValue())+((java.lang.Integer)field_nBSRptSchm2Col1.getValue())); //$JR_EXPR_ID=8$

then I used the following code to add the columns of Integer type…

new Integer($F{nSchm1Col1}.intValue() + $F{Schm2Col1}.intValue() )

where nSchm1Col1 and Schm2col1 are two fields which I want to add. This one worked for me