JasperReports中的组有助于以逻辑方式组织报告数据.报告组表示数据源中的一系列连续记录,这些记录具有一些共同点,例如某些报告字段的值.报告组由< group>定义.元件.报告可以包含任意数量的组.声明后,可以在整个报告中引用组.
报告组有三个元素 :
群组表达 : 这表示必须更改以启动新数据组的数据.
组标题部分 : 帮助将标签放在分组数据的开头.
组页脚部分 : 帮助将标签放在分组数据的末尾.
在报告填充时迭代数据源期间如果值为组表达发生变化,发生组破裂并且相应的< groupFooter>和< groupHeader>在生成的文档中插入了部分.
报告组机制不对数据源提供的数据执行任何排序.只有当数据源中的记录已根据报告中使用的组表达式进行排序时,数据分组才能按预期工作.
<组> element包含允许我们控制分组数据布局方式的属性.属性汇总在下表和减号中;
S.NO | 属性和描述 |
---|---|
1 | 名称 这是强制性的.它按名称引用报表表达式中的组.它遵循我们为报表参数,字段和报表变量提到的相同命名约定.当您想引用特定的报告组时,它可以在其他JRXML属性中使用. |
2 | isStartNewColumn 当设置为 true 时,每个数据组将从一个新专栏.默认值为 false . |
3 | isStartNewPage 当设置为 true 时,每个数据组将在新页面上开始.默认值为 false . |
4 | isResetPageNumber 设置为 true 时,每次新组时都会重置报告页码开始.默认值为 false. |
5 | isReprintHeaderOnEachPage 当设置为 true 时,将在每个页面上重新打印组标题.默认值为 false . |
6 | minHeightToStartNewPage 定义列底部所需的最小垂直空间量,以便将组标题放在当前列上.金额以报告单位指定. |
7 | footerPosition 在页面上呈现组页脚的位置,以及与其后面的报表部分相关的行为.它的值可以be:正常, StackAtBottom , ForceAtBottom 和 CollateAtBottom .默认值为正常. |
8 | keepTogether 当设置为 true 时,阻止该组在第一次中断尝试时分裂. |
让我们添加一个组( CountryGroup )到现有报告模板(章报告设计).计算每个国家/地区的出现次数,并将计数显示为组页脚.在组头中,每个记录的计数都是前缀.修订后的报告模板(jasper_report_template.jrxml)如下所示.将其保存到C:\tools\jasperreports-5.0.1 \ test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>
报告填充的java代码保持不变.文件 C:\tools\jasperreports-5.0.1\test\src\com\it1352\ JapersReportFill.java 的内容如下所示 :
package com.it1352; 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(); } } }
POJO文件的内容 C:\tools\jasperreports -5.0.1\test\src\com\it1352\ DataBean.java 如下 :
package com.it1352; 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; } }
文件的内容 C:\tools\jasperreports-5.0.1 \ test \src\com\it1352\ DataBeanList.java 如下所示 :
package com. it1352; 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; } }
我们将编译并执行上述文件我们定期的ANT构建过程.文件build.xml的内容(保存在目录C:\tools \jasperreports-5.0.1 \ test下面)如下所示.
导入文件 - baseBuild.xml从环境设置一章中选取,并且应该与build.xml放在同一目录中.
<?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所在的目录.最后,执行命令 ant -Dmain-class = com.it1352.JasperReportFill (viewFullReport是默认目标)为 :
C:\tools\jasperreports-5.0.1\test>ant -Dmain-class=com.IT屋.JasperReportFill Buildfile: C:\tools\jasperreports-5.0.1\test\build.xml clean-sample: [delete] Deleting directory C:\tools\jasperreports-5.0.1\test\classes [delete] Deleting: C:\tools\jasperreports-5.0.1\test\jasper_report_template.jasper [delete] Deleting: C:\tools\jasperreports-5.0.1\test\jasper_report_template.jrprint compile: [mkdir] Created dir: C:\tools\jasperreports-5.0.1\test\classes [javac] C:\tools\jasperreports-5.0.1\test\baseBuild.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:\tools\jasperreports-5.0.1\test\classes 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.html#noconfig for more info. [jrc] File : C:\tools\jasperreports-5.0.1\test\jasper_report_template.jrxml ... OK. run: [echo] Runnin class : com.IT屋.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
由于上面的编译,JasperViewer窗口打开为在屏幕下方 :
在这里,我们看到每个国家都被分组,每个国家的发生次数都显示在每个国家的页脚中.