我使用JasperReports制作了一个报告，它已经可以使用，但我想从Set类型对象的值构造一个String。我正在使用以下表达式来填充我的文本字段：
$F{resultat}.getTypeResultats().iterator().next().getDescription()+ ". " +
(($F{resultat}.getTypeResultats().iterator().hasNext()) ?
$F{resultat}.getTypeResultats().iterator().next().getDescription() : "")
我从Field获得了预期值，但它始终获得Set中的第一个元素。
如何迭代我的设置？
感谢您的帮助。
这是子报告：
<?xml version="1.0" encoding="UTF-8"?>
<!-- Created with Jaspersoft Studio version 6.3.1.final using JasperReports Library version 3.7.5 -->
<!-- 2017-03-27T14:34:04 -->
<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="FicheEpisode_Declarations" pageWidth="552" pageHeight="792" columnWidth="552" leftMargin="0" rightMargin="0" topMargin="0" bottomMargin="0">
<property name="ireport.scriptlethandling" value="0"/>
<property name="ireport.encoding" value="UTF-8"/>
<property name="net.sf.jasperreports.awt.ignore.missing.font" value="true"/>
<property name="ireport.zoom" value="1.771561000000001"/>
<property name="ireport.x" value="0"/>
<property name="ireport.y" value="0"/>
<import value="org.apache.commons.lang.StringUtils"/>
<import value="net.sf.jasperreports.engine.*"/>
<import value="java.util.*"/>
<import value="net.sf.jasperreports.engine.data.*"/>
<subDataset name="Dataset1">
<property name="com.jaspersoft.studio.data.defaultdataadapter" value="One Empty Record"/>
<queryString>
<![CDATA[]]>
</queryString>
</subDataset>
<field name="dateDeclaration" class="java.util.Date"/>
<field name="dateReception" class="java.util.Date"/>
<field name="declarantAutre" class="java.lang.String"/>
<field name="casMaladie" class="com.openpole.mado.bo.CasMaladie"/>
<field name="modeDeclaration" class="com.openpole.mado.bo.ModeDeclaration"/>
<field name="medecinDeclarant" class="com.openpole.mado.bo.Medecin"/>
<field name="laboratoireDeclarant" class="com.openpole.mado.bo.Laboratoire"/>
<field name="resultat" class="com.openpole.mado.bo.Resultat"/>
<background>
<band height="11" splitType="Stretch"/>
</background>
<title>
<band height="1" splitType="Stretch"/>
</title>
<pageHeader>
<band splitType="Stretch"/>
</pageHeader>
<columnHeader>
<band splitType="Stretch"/>
</columnHeader>
<detail>
<band height="86" splitType="Stretch">
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="lblIdentification" positionType="Float" mode="Transparent" x="0" y="3" width="101" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$R{rapport.ficheEpisode.decl.typeDeclaration} + " :"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="lblIdentification" positionType="Float" mode="Transparent" x="0" y="18" width="101" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$R{rapport.ficheEpisode.decl.dateDeclaration} + " :"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="lblIdentification" positionType="Float" mode="Transparent" x="0" y="46" width="101" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$R{rapport.ficheEpisode.decl.methodeDeclaration} + " :"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="lblIdentification" positionType="Float" mode="Transparent" x="0" y="32" width="101" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<leftPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<bottomPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$R{rapport.ficheEpisode.decl.dateReception} + " :"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="yyyy-MM-dd" isBlankWhenNull="true">
<reportElement key="fldDateDeclaration" mode="Transparent" x="154" y="18" width="92" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.util.Date"><![CDATA[$F{dateDeclaration}]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="yyyy-MM-dd" isBlankWhenNull="true">
<reportElement key="fldDateReception" mode="Transparent" x="154" y="32" width="92" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<leftPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<bottomPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.util.Date"><![CDATA[$F{dateReception}]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="fldModeDeclaration" mode="Transparent" x="154" y="46" width="275" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<leftPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$F{modeDeclaration}.getDescription()]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="fldNomDeclarant" mode="Transparent" x="154" y="3" width="273" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<leftPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<bottomPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$F{medecinDeclarant} != null ?
$R{rapport.ficheEpisode.decl.medecin} + " (" + $F{medecinDeclarant}.getPrenom() + " " + $F{medecinDeclarant}.getNom() + ")":
$F{laboratoireDeclarant} != null ?
$R{rapport.ficheEpisode.decl.laboratoire} + " (" + $F{laboratoireDeclarant}.getDescription() + ")":
$R{rapport.ficheEpisode.decl.autre} + " (" + StringUtils.trimToEmpty($F{declarantAutre}) + ")"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="lblIdentification" positionType="Float" mode="Transparent" x="0" y="60" width="101" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<leftPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$R{rapport.ficheEpisode.res.sourceInfection} + " :"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="lblIdentification" positionType="Float" mode="Transparent" x="0" y="75" width="101" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
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</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$R{rapport.ficheEpisode.res.typeResultat} + " :"]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="fldMicroOrganisme-1" mode="Transparent" x="154" y="61" width="275" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
<box>
<topPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
<leftPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
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</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$F{resultat}.getMicroOrganismes().iterator().next().getDescription()]]></textFieldExpression>
</textField>
<textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true">
<reportElement key="fldMicroOrganisme-1" mode="Transparent" x="154" y="75" width="275" height="11" forecolor="#000000" backcolor="#FFFFFF"/>
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<rightPen lineWidth="0.0" lineStyle="Solid" lineColor="#000000"/>
</box>
<textElement textAlignment="Left" verticalAlignment="Top" rotation="None" lineSpacing="Single" markup="none">
<font fontName="SansSerif" size="8" isBold="false" isItalic="false" isUnderline="false" isStrikeThrough="false" pdfFontName="Helvetica" pdfEncoding="Cp1252" isPdfEmbedded="false"/>
</textElement>
<textFieldExpression class="java.lang.String"><![CDATA[$F{resultat}.getTypeResultats().iterator().next().getDescription()+ ". " +(($F{resultat}.getTypeResultats().iterator().hasNext()) ? $F{resultat}.getTypeResultats().iterator().next().getDescription() : "")]]></textFieldExpression>
</textField>
</band>
</detail>
<columnFooter>
<band splitType="Stretch"/>
</columnFooter>
<pageFooter>
<band splitType="Stretch"/>
</pageFooter>
<summary>
<band splitType="Stretch"/>
</summary>
</jasperReport>