JasperReports报表组 - JasperReports教程
组在JasperReports的协助组织对报告的数据以逻辑方式。报告组代表连续记录的数据源中有一些共同点，比如某个报表字段的值的序列。报告组由<group>元素定义。一个报表可以有任意数量的组。一旦声明，群体可以在整个报告中提到的。
报告组有三个要素：
Group expression: 这表示必须改变，以启动一个新的数据组中的数据。
Group header section: 帮助位置标签在分组数据的开始。
Group footer section: : 帮助位置标签在分组数据的末尾。
在截至于若该组表达变化，一组发生断裂和相应的<groupFooter>和<groupHeader>部分的值插入到生成的文档中报告充填时数据源的迭代。
> 报表组的机制不执行由数据源所提供的资料的任何排序。数据分组按预期工作，只有当数据源中的记录按照报告中使用的组表达式已经下令。
属性组
<group>元素包含属性，使我们能够控制分组的数据是如何布局。属性概括于下表：
| 属性 | 描述 |
|---|---|
| name | 这是强制性的。它通过名称引用该组中的报表表达式。它遵循相同的命名约定我们，我们提到的报告参数，字段和报表变量。它可以在其他JRXML属性被用于当想引用一个特定的报告组。 |
| isStartNewColumn | 当设置为true时，每个数据组将开始一个新的列。默认值是false |
| isStartNewPage | 当设置为true时，每个数据组将开始一个新的页面上。默认值是false |
| isResetPageNumber | 当设置为true，该报告页码将每一个新组开始时被重置。默认值是false |
| isReprintHeaderOnEachPage | 当设置为true时，组头会被重印每一页上。默认值是false |
| minHeightToStartNewPage | 定义在列的底部，以便将组头当前列所需要的垂直空间最小量。被指定在报告单位的数量。 |
| footerPosition | 呈现在页面上的组页脚的位置，以及其有关的报告的部分它后面的行为。它的值可以是: Normal, StackAtBottom, ForceAtBottom, CollateAtBottom.默认值是 Normal |
| keepTogether | 当设置为true，将阻止该集团从分割它第一次突破的尝试 |
例子
让我们添加一个组（CountryGroup）现有的报告模板（章报表设计）。每个国家的次数进行计数，计数显示为组页脚。在组头中每个记录的计数前缀。修订后的报告模板（jasper_report_template.jrxml）如下。将其保存到 C: oolsjasperreports-5.0.1 est 目录：
<?xml version="1.0"?>
<!DOCTYPE jasperReport PUBLIC
"//JasperReports//DTD Report Design//EN"
"http://jasperreports.sourceforge.net/dtds/jasperreport.dtd">
<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="jasper_report_template" pageWidth="595"
pageHeight="842" columnWidth="515"
leftMargin="40" rightMargin="40" topMargin="50" bottomMargin="50">
<parameter name="ReportTitle" class="java.lang.String"/>
<parameter name="Author" class="java.lang.String"/>
<queryString>
<![CDATA[]]>
</queryString>
<field name="country" class="java.lang.String">
<fieldDescription><![CDATA[country]]></fieldDescription>
</field>
<field name="name" class="java.lang.String">
<fieldDescription><![CDATA[name]]></fieldDescription>
</field>
<sortField name="country" order="Descending"/>
<sortField name="name"/>
<variable name="CountryNumber" class="java.lang.Integer"
incrementType="Group" incrementGroup="CountryGroup"
calculation="Count">
<variableExpression><![CDATA[Boolean.TRUE]]></variableExpression>
</variable> **<group name="CountryGroup" minHeightToStartNewPage="60">
<groupExpression><![CDATA[$F{country}]]></groupExpression>
<groupHeader>
<band height="20">
<textField evaluationTime="Group" evaluationGroup="CountryGroup"
bookmarkLevel="1">
<reportElement mode="Opaque" x="0" y="5" width="515"
height="15" backcolor="#C0C0C0"/>
<box leftPadding="10">
<bottomPen lineWidth="1.0"/>
</box>
<textElement/>
<textFieldExpression class="java.lang.String">
<![CDATA[" " + String.valueOf($V{CountryNumber}) + ". "
+ String.valueOf($F{country})]]>
</textFieldExpression>
<anchorNameExpression>
<![CDATA[String.valueOf($F{country})]]>
</anchorNameExpression>
</textField>
</band>
</groupHeader>
<groupFooter>
<band height="20">
<staticText>
<reportElement x="400" y="1" width="60" height="15"/>
<textElement textAlignment="Right"/>
<text><![CDATA[Count :]]></text>
</staticText>
<textField>
<reportElement x="460" y="1" width="30" height="15"/>
<textElement textAlignment="Right"/>
<textFieldExpression class="java.lang.Integer">
<![CDATA[$V{CountryGroup_COUNT}]]>
</textFieldExpression>
</textField>
</band>
</groupFooter>
</group>**
<title>
<band height="70">
<line>
<reportElement x="0" y="0" width="515"
height="1"/>
</line>
<textField isBlankWhenNull="true" bookmarkLevel="1">
<reportElement x="0" y="10" width="515"
height="30"/>
<textElement textAlignment="Center">
<font size="22"/>
</textElement>
<textFieldExpression class="java.lang.String">
<![CDATA[$P{ReportTitle}]]>
</textFieldExpression>
<anchorNameExpression><![CDATA["Title"]]>
</anchorNameExpression>
</textField>
<textField isBlankWhenNull="true">
<reportElement x="0" y="40" width="515" height="20"/>
<textElement textAlignment="Center">
<font size="10"/>
</textElement>
<textFieldExpression class="java.lang.String">
<![CDATA[$P{Author}]]>
</textFieldExpression>
</textField>
</band>
</title>
<columnHeader>
<band height="23">
<staticText>
<reportElement mode="Opaque" x="0" y="3"
width="535" height="15"
backcolor="#70A9A9" />
<box>
<bottomPen lineWidth="1.0"
lineColor="#CCCCCC" />
</box>
<textElement />
<text><![CDATA[]]>
</text>
</staticText>
<staticText>
<reportElement x="414" y="3" width="121"
height="15" />
<textElement textAlignment="Center"
verticalAlignment="Middle">
<font isBold="true" />
</textElement>
<text><![CDATA[Country]]></text>
</staticText>
<staticText>
<reportElement x="0" y="3" width="136"
height="15" />
<textElement textAlignment="Center"
verticalAlignment="Middle">
<font isBold="true" />
</textElement>
<text><![CDATA[Name]]></text>
</staticText>
</band>
</columnHeader>
<detail>
<band height="16">
<staticText>
<reportElement mode="Opaque" x="0" y="0"
width="535" height="14"
backcolor="#E5ECF9" />
<box>
<bottomPen lineWidth="0.25"
lineColor="#CCCCCC" />
</box>
<textElement />
<text><![CDATA[]]>
</text>
</staticText>
<textField>
<reportElement x="414" y="0" width="121"
height="15" />
<textElement textAlignment="Center"
verticalAlignment="Middle">
<font size="9" />
</textElement>
<textFieldExpression class="java.lang.String">
<![CDATA[$F{country}]]>
</textFieldExpression>
</textField>
<textField>
<reportElement x="0" y="0" width="136"
height="15" />
<textElement textAlignment="Center"
verticalAlignment="Middle" />
<textFieldExpression class="java.lang.String">
<![CDATA[$F{name}]]>
</textFieldExpression>
</textField>
</band>
</detail>
</jasperReport>
在java代码报表填充保持不变。该文件的内容 C: oolsjasperreports-5.0.1 estsrccomyiibaiJasperReportFill.java 如下：
package com.yiibai;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;
public class JasperReportFill {
@SuppressWarnings("unchecked")
public static void main(String[] args) {
String sourceFileName =
"C://tools/jasperreports-5.0.1/test/jasper_report_template.jasper";
DataBeanList DataBeanList = new DataBeanList();
ArrayList<DataBean> dataList = DataBeanList.getDataBeanList();
JRBeanCollectionDataSource beanColDataSource =
new JRBeanCollectionDataSource(dataList);
Map parameters = new HashMap();
/**
* Passing ReportTitle and Author as parameters
*/
parameters.put("ReportTitle", "List of Contacts");
parameters.put("Author", "Prepared By Manisha");
try {
JasperFillManager.fillReportToFile(
sourceFileName, parameters, beanColDataSource);
} catch (JRException e) {
e.printStackTrace();
}
}
}
该POJO文件的内容 C: oolsjasperreports-5.0.1 estsrccomyiibaiDataBean.java 如下：
package com.yiibai;
public class DataBean {
private String name;
private String country;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCountry() {
return country;
}
public void setCountry(String country) {
this.country = country;
}
}
该文件的内容C: oolsjasperreports-5.0.1 estsrccomyiibaiDataBeanList.java 如下：
package com.yiibai;
import java.util.ArrayList;
public class DataBeanList {
public ArrayList<DataBean> getDataBeanList() {
ArrayList<DataBean> dataBeanList = new ArrayList<DataBean>();
dataBeanList.add(produce("Manisha", "India"));
dataBeanList.add(produce("Dennis Ritchie", "USA"));
dataBeanList.add(produce("V.Anand", "India"));
dataBeanList.add(produce("Shrinath", "California"));
return dataBeanList;
}
/**
* This method returns a DataBean object,
* with name and country set in it.
*/
private DataBean produce(String name, String country) {
DataBean dataBean = new DataBean();
dataBean.setName(name);
dataBean.setCountry(country);
return dataBean;
}
}
报表生成
我们将编译和执行使用我们常规Ant构建过程上面的文件.build.xml文件中的内容（根据目录保存 C: oolsjasperreports-5.0.1 est）如下：
<?xml version="1.0" encoding="UTF-8"?>
<project name="JasperReportTest" default="viewFillReport" basedir=".">
<import file="baseBuild.xml" />
<target name="viewFillReport"
depends="compile,compilereportdesing,run"
description="Launches the report viewer to preview
the report stored in the .JRprint file.">
<java classname="net.sf.jasperreports.view.JasperViewer"
fork="true">
<arg value="-F${file.name}.JRprint" />
<classpath refid="classpath" />
</java>
</target>
<target name="compilereportdesing"
description="Compiles the JXML file and
produces the .jasper file.">
<taskdef name="jrc"
classname="net.sf.jasperreports.ant.JRAntCompileTask">
<classpath refid="classpath" />
</taskdef>
<jrc destdir=".">
<src>
<fileset dir=".">
<include name="*.jrxml" />
</fileset>
</src>
<classpath refid="classpath" />
</jrc>
</target>
</project>
接下来，让我们打开命令行窗口并转到build.xml文件放置的目录。最后执行的命令ant -Dmain-class=com.yiibai.JasperReportFill （viewFullReport是默认的目标），如下所示：
C: oolsjasperreports-5.0.1 est>ant -Dmain-class=com.yiibai.JasperReportFill
Buildfile: C: oolsjasperreports-5.0.1 estuild.xml
clean-sample:
[delete] Deleting directory C: oolsjasperreports-5.0.1 estclasses
[delete] Deleting: C: oolsjasperreports-5.0.1 estjasper_report_template.jasper
[delete] Deleting: C: oolsjasperreports-5.0.1 estjasper_report_template.jrprint
compile:
[mkdir] Created dir: C: oolsjasperreports-5.0.1 estclasses
[javac] C: oolsjasperreports-5.0.1 estaseBuild.xml:28: warning:
'includeantruntime' was not set, defaulting to build.sysclasspath=last;
set to false for repeatable builds
[javac] Compiling 7 source files to C: oolsjasperreports-5.0.1 estclasses
compilereportdesing:
[jrc] Compiling 1 report design files.
[jrc] log4j:WARN No appenders could be found for logger
(net.sf.jasperreports.engine.xml.JRXmlDigesterFactory).
[jrc] log4j:WARN Please initialize the log4j system properly.
[jrc] log4j:WARN See http://logging.apache.org/log4j/1.2/faq.htmll#noconfig
for more info.
[jrc] File : C: oolsjasperreports-5.0.1 estjasper_report_template.jrxml ... OK.
run:
[echo] Runnin class : com.yiibai.JasperReportFill
[java] log4j:WARN No appenders could be found for logger
(net.sf.jasperreports.extensions.ExtensionsEnvironment).
[java] log4j:WARN Please initialize the log4j system properly.
viewFillReport:
[java] log4j:WARN No appenders could be found for logger
(net.sf.jasperreports.extensions.ExtensionsEnvironment).
[java] log4j:WARN Please initialize the log4j system properly.
BUILD SUCCESSFUL
Total time: 18 seconds
正如上文编译的结果，JasperViewer窗口打开如下面的屏幕：
在这里，我们看到，各个国家分组和发生每个国家的计数显示在每个组页脚。