Tukukkk

I've been struggling for the last week with this issue and I couldn't solve it.
Using Mapfish Print 3 on Tomcat with browser I'm trying to print a .jrxml template produced in Jaspersoft Studio. Datasource for the template is a .json, containing tables.

When I print the pdf from jaspersoft studio everything works fine, but when I print it from Mapfish, the fields of my tables are not populated, so that I have correct table column names and below just one row filled with "null".

Tomcat log throws this error:

gradle: 09:34:01.835 [PrintJobManager-3] WARN  o.m.p.o.AbstractJasperReportOutputFormat - The field letter in prova_json.jrxml is not available in at least one of the rows in the datasource.  This may not be an error.

gradle: 09:34:01.835 [PrintJobManager-3] WARN  o.m.p.o.AbstractJasperReportOutputFormat - The field number in prova_json.jrxml is not available in at least one of the rows in the datasource.  This may not be an error.

Actual result
Desired result

I looked into the template data adapters, .yaml and .json configuration, but nothing. I'm quite new at this and I might be forgetting some basic stuff.

I would be really glad if someone could help.

Many thanks

This is my .yaml:

templates:

  A4 portrait: !template

    reportTemplate: prova_json.jrxml

    attributes:

      title: !string

        default: "Mytable"

    processors:

    - !reportBuilder

      directory: '.'

This is my .json:

{

  "layout": "A4 portrait",

  "outputFormat": "pdf",

  "attributes": {},

  "example":[

    {"letter":"A", "number":"1"},

    {"letter":"B", "number":"2"},

    {"letter":"C", "number":"3"}

              ]

}

This is my .jrxml:

<?xml version="1.0" encoding="UTF-8"?>

<!-- Created with Jaspersoft Studio version 6.6.0.final using JasperReports Library version 6.6.0  -->

<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="prova_json" pageWidth="595" pageHeight="842" columnWidth="555" leftMargin="20" rightMargin="20" topMargin="20" bottomMargin="20" uuid="443dccec-8ac9-486f-b9e2-bf8809609b24">

    <property name="com.jaspersoft.studio.data.defaultdataadapter" value="requestData"/>

    <parameter name="title" class="java.lang.String"/>

    <queryString language="json">

        <![CDATA[example]]>

    </queryString>

    <field name="letter" class="java.lang.String">

        <property name="net.sf.jasperreports.json.field.expression" value="letter"/>

        <fieldDescription><![CDATA[letter]]></fieldDescription>

    </field>

    <field name="number" class="java.lang.Integer">

        <property name="net.sf.jasperreports.json.field.expression" value="number"/>

        <fieldDescription><![CDATA[number]]></fieldDescription>

    </field>

    <background>

        <band splitType="Stretch"/>

    </background>

    <title>

        <band height="50" splitType="Stretch">

            <textField>

                <reportElement x="230" y="20" width="100" height="30" uuid="e15aa58f-c3f8-415c-b783-9d99cd9fd936"/>

                <box>

                    <topPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <leftPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <bottomPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <rightPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                </box>

                <textElement textAlignment="Center" verticalAlignment="Middle"/>

                <textFieldExpression><![CDATA[$P{title}]]></textFieldExpression>

            </textField>

        </band>

    </title>

    <pageHeader>

        <band height="35" splitType="Stretch"/>

    </pageHeader>

    <columnHeader>

        <band height="30" splitType="Stretch">

            <staticText>

                <reportElement x="100" y="0" width="180" height="30" uuid="710e904e-be4b-4827-bed5-cba2caa930af">

                    <property name="com.jaspersoft.studio.spreadsheet.connectionID" value="fca73b4c-ec21-4d8e-8103-e847788aa7d0"/>

                </reportElement>

                <box>

                    <topPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <leftPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <bottomPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <rightPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                </box>

                <textElement textAlignment="Center" verticalAlignment="Middle"/>

                <text><![CDATA[letter]]></text>

            </staticText>

            <staticText>

                <reportElement x="280" y="0" width="175" height="30" uuid="2434f475-1bf1-428b-9eda-428133d8f1e3">

                    <property name="com.jaspersoft.studio.spreadsheet.connectionID" value="70d93515-4ef5-4746-acac-b96c8b4f43c9"/>

                </reportElement>

                <box>

                    <topPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <leftPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <bottomPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <rightPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                </box>

                <textElement textAlignment="Center" verticalAlignment="Middle"/>

                <text><![CDATA[number]]></text>

            </staticText>

        </band>

    </columnHeader>

    <detail>

        <band height="30" splitType="Stretch">

            <textField>

                <reportElement x="100" y="0" width="180" height="30" uuid="bf808ed8-1e3e-4d6f-9e62-03c2491b89cd">

                    <property name="com.jaspersoft.studio.spreadsheet.connectionID" value="fca73b4c-ec21-4d8e-8103-e847788aa7d0"/>

                </reportElement>

                <box>

                    <topPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <leftPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <bottomPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <rightPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                </box>

                <textElement textAlignment="Center" verticalAlignment="Middle"/>

                <textFieldExpression><![CDATA[$F{letter}]]></textFieldExpression>

            </textField>

            <textField>

                <reportElement x="280" y="0" width="175" height="30" uuid="e53139cc-0aee-4f5a-8b45-55123ae024fd">

                    <property name="com.jaspersoft.studio.spreadsheet.connectionID" value="70d93515-4ef5-4746-acac-b96c8b4f43c9"/>

                </reportElement>

                <box>

                    <topPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <leftPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <bottomPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                    <rightPen lineWidth="1.0" lineStyle="Solid" lineColor="#000000"/>

                </box>

                <textElement textAlignment="Center" verticalAlignment="Middle"/>

                <textFieldExpression><![CDATA[$F{number}]]></textFieldExpression>

            </textField>

        </band>

    </detail>

    <columnFooter>

        <band height="45" splitType="Stretch"/>

    </columnFooter>

    <pageFooter>

        <band height="54" splitType="Stretch"/>

    </pageFooter>

    <summary>

        <band height="42" splitType="Stretch"/>

    </summary>

</jasperReport>