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JasperReports報表組

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組在JasperReports的協助組織對報告的數據以邏輯方式。報告組代表連續記錄的數據源中有一些共同點，比如某個報表字段的值的序列。報告組由<group>元素定義。一個報表可以有任意數量的組。一旦聲明，群體可以在整個報告中提到的。

報告組有三個要素：

  • Group expression: 這表示必須改變，以啟動一個新的數據組中的數據。

  • Group header section: 幫助位置標簽在分組數據的開始。

  • Group footer section: : 幫助位置標簽在分組數據的末尾。

在截至於若該組表達變化，一組發生斷裂和相應的<groupFooter>和<groupHeader>部分的值插入到生成的文檔中報告充填時數據源的迭代。

報表組的機製不執行由數據源所提供的資料的任何排序。數據分組按預期工作，隻有當數據源中的記錄按照報告中使用的組表達式已經下令。

屬性組

<group>元素包含屬性，使我們能夠控製分組的數據是如何布局。屬性概括於下表：

屬性 描述
name 這是強製性的。它通過名稱引用該組中的報表表達式。它遵循相同的命名約定我們，我們提到的報告參數，字段和報表變量。它可以在其他JRXML屬性被用於當想引用一個特定的報告組。
isStartNewColumn 當設置為true時，每個數據組將開始一個新的列。默認值是false
isStartNewPage 當設置為true時，每個數據組將開始一個新的頁麵上。默認值是false
isResetPageNumber 當設置為true，該報告頁碼將每一個新組開始時被重置。默認值是false
isReprintHeaderOnEachPage 當設置為true時，組頭會被重印每一頁上。默認值是false
minHeightToStartNewPage 定義在列的底部，以便將組頭當前列所需要的垂直空間最小量。被指定在報告單位的數量。
footerPosition 呈現在頁麵上的組頁腳的位置，以及其有關的報告的部分它後麵的行為。它的值可以是: Normal, StackAtBottom, ForceAtBottom, CollateAtBottom.默認值是 Normal
keepTogether 當設置為true，將阻止該集團從分割它第一次突破的嘗試

例子

讓我們添加一個組（CountryGroup）現有的報告模板（章報表設計）。每個國家的次數進行計數，計數顯示為組頁腳。在組頭中每個記錄的計數前綴。修訂後的報告模板（jasper_report_template.jrxml）如下。將其保存到 C: oolsjasperreports-5.0.1 est 目錄：

<?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代碼報表填充保持不變。該文件的內容 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();
      }
   }
}

該POJO文件的內容 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;
   }
}

該文件的內容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;
   }
}

報表生成

我們將編譯和執行使用我們常規Ant構建過程上麵的文件.build.xml文件中的內容（根據目錄保存 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>

接下來，讓我們打開命令行窗口並轉到build.xml文件放置的目錄。最後執行的命令ant -Dmain-class=com.yiibai.JasperReportFill （viewFullReport是默認的目標），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

正如上文編譯的結果，JasperViewer窗口打開如下麵的屏幕：

Jasper Report Viewer

在這裡，我們看到，各個國家分組和發生每個國家的計數顯示在每個組頁腳。



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