Grand Total in report - jasper-reports

Question

This is my code for Grandtotal but it won't have grandtotal ?
<?xml version="1.0" encoding="UTF-8"?>
<jasperReport xmlns="http://jasperreports.sourceforge.net/jasperreports" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://jasperreports.sourceforge.net/jasperreports http://jasperreports.sourceforge.net/xsd/jasperreport.xsd" name="Warehouse" language="groovy" pageWidth="612" pageHeight="792" columnWidth="572" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20">
<queryString language="SQL">
<![CDATA[select * from warehouse]]>
</queryString>
<field name="PlantUnit" class="java.lang.String"/>
<field name="Description" class="java.lang.String"/>
<field name="Size" class="java.lang.String"/>
<field name="Qty" class="java.lang.String"/>
<field name="Unit" class="java.lang.String"/>
<field name="Unit Price" class="java.lang.String"/>
<field name="Amount" class="java.lang.String"/>
<variable name="TotalAmount" class="java.lang.String" calculation="Sum">
<variableExpression><![CDATA[$F{Amount}]]></variableExpression>
</variable>
<background>
<band splitType="Stretch"/>
</background>
<title>
<band height="40" splitType="Stretch">
<staticText>
<reportElement x="100" y="0" width="409" height="40"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="34" isBold="true"/>
</textElement>
<text><![CDATA[WAREHOUSE]]></text>
</staticText>
</band>
</title>
<pageHeader>
<band height="15" splitType="Stretch">
<textField pattern="MMMMM dd, yyyy">
<reportElement x="457" y="0" width="116" height="15"/>
<textElement textAlignment="Right">
<font fontName="Times New Roman" size="12"/>
</textElement>
<textFieldExpression><![CDATA[new SimpleDateFormat("MMMM dd, yyyy").format(new java.util.Date())]]></textFieldExpression>
</textField>
</band>
</pageHeader>
<columnHeader>
<band height="12" splitType="Stretch">
<staticText>
<reportElement x="0" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10" isBold="true"/>
</textElement>
<text><![CDATA[PU]]></text>
</staticText>
<staticText>
<reportElement x="50" y="0" width="184" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10" isBold="true"/>
</textElement>
<text><![CDATA[DESCRIPTION]]></text>
</staticText>
<staticText>
<reportElement x="234" y="0" width="150" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10" isBold="true"/>
</textElement>
<text><![CDATA[SIZE]]></text>
</staticText>
<staticText>
<reportElement x="384" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10" isBold="true"/>
</textElement>
<text><![CDATA[QTY]]></text>
</staticText>
<staticText>
<reportElement x="434" y="0" width="40" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10" isBold="true"/>
</textElement>
<text><![CDATA[UNIT]]></text>
</staticText>
<staticText>
<reportElement x="473" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" isBold="true"/>
</textElement>
<text><![CDATA[COST]]></text>
</staticText>
<staticText>
<reportElement x="523" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" isBold="true"/>
</textElement>
<text><![CDATA[AMOUNT]]></text>
</staticText>
<rectangle>
<reportElement mode="Transparent" x="0" y="0" width="50" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="50" y="0" width="184" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="234" y="0" width="150" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="384" y="0" width="50" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="434" y="0" width="40" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="474" y="0" width="49" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="523" y="0" width="50" height="12"/>
</rectangle>
</band>
</columnHeader>
<detail>
<band height="12" splitType="Stretch">
<textField>
<reportElement x="0" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10"/>
</textElement>
<textFieldExpression><![CDATA[$F{PlantUnit}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="50" y="0" width="184" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10"/>
</textElement>
<textFieldExpression><![CDATA[$F{Description}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="234" y="0" width="150" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10"/>
</textElement>
<textFieldExpression><![CDATA[$F{Size}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="384" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10"/>
</textElement>
<textFieldExpression><![CDATA[$F{Qty}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="433" y="0" width="40" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman" size="10"/>
</textElement>
<textFieldExpression><![CDATA[$F{Unit}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="473" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman"/>
</textElement>
<textFieldExpression><![CDATA[$F{Unit Price}]]></textFieldExpression>
</textField>
<textField>
<reportElement x="523" y="0" width="50" height="12"/>
<textElement textAlignment="Center">
<font fontName="Times New Roman"/>
</textElement>
<textFieldExpression><![CDATA[$F{Amount}]]></textFieldExpression>
</textField>
<rectangle>
<reportElement mode="Transparent" x="0" y="0" width="50" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="50" y="0" width="184" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="234" y="0" width="150" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="384" y="0" width="50" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="434" y="0" width="40" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="474" y="0" width="49" height="12"/>
</rectangle>
<rectangle>
<reportElement mode="Transparent" x="523" y="0" width="50" height="12"/>
</rectangle>
</band>
</detail>
<columnFooter>
<band height="12" splitType="Stretch">
<staticText>
<reportElement x="0" y="0" width="100" height="12"/>
<textElement>
<font fontName="Times New Roman" isBold="true"/>
</textElement>
<text><![CDATA[Total Amount]]></text>
</staticText>
<textField isBlankWhenNull="true">
<reportElement x="473" y="0" width="100" height="12"/>
<textElement textAlignment="Right">
<font fontName="Times New Roman"/>
</textElement>
<textFieldExpression><![CDATA[$V{TotalAmount}]]></textFieldExpression>
</textField>
</band>
</columnFooter>
<pageFooter>
<band height="15" splitType="Stretch">
<textField>
<reportElement x="491" y="0" width="56" height="15"/>
<textElement textAlignment="Right">
<font fontName="Times New Roman" size="12"/>
</textElement>
<textFieldExpression><![CDATA["Page "+$V{PAGE_NUMBER}+" of"]]></textFieldExpression>
</textField>
<textField evaluationTime="Report">
<reportElement x="547" y="0" width="25" height="15"/>
<textElement>
<font fontName="Times New Roman" size="12"/>
</textElement>
<textFieldExpression><![CDATA[" " + $V{PAGE_NUMBER}]]></textFieldExpression>
</textField>
</band>
</pageFooter>
<summary>
<band height="11" splitType="Stretch"/>
</summary>
</jasperReport>
Further assistance would be appreciated.

Answer 1

You have taken the amount field as string.
<field name="Amount" class="java.lang.String"/>
And your variable type is also string.
<variable name="TotalAmount" class="java.lang.String" calculation="Sum">
<variableExpression><![CDATA[$F{Amount}]]></variableExpression>
</variable>
You need to have Amount and TotalAmount variables to be Integer in order for jasper report to be able to calculate the sum. Hence change it to following:
<field name="Amount" class="java.lang.Integer"/>
and
<variable name="TotalAmount" class="java.lang.Integer" calculation="Sum">
<variableExpression><![CDATA[$F{Amount}]]></variableExpression>
</variable>
Note : If Amount is already String then convert it to Integer and then feed to jasper report.