任何报告工具的主要目的是生成高质量的文档.报告填写过程有助于报告工具通过操作数据集来实现这一目标.
报告填写过程所需的主要输入是 :
报告模板 : 这是实际的JasperReport文件.
报告参数 : 这些基本上是在报告填充时传递给引擎的命名值.我们将在报告参数章节中讨论它们.
数据源 : 我们可以从一系列数据源填充Jasper文件，如SQL查询，XML文件，csv文件，HQL(Hibernate查询语言)查询，Java Bean集合等.这将在
输出此过程生成的是 .jrprint 文档，可以查看，打印或导出为其他格式. Facade类 net.sf.jasperreports.engine.JasperFillManager 通常用于填充包含数据的报告模板.此类具有各种 fillReportXXX()方法，用于填充报告模板(模板可以位于磁盘上，从输入流中挑选，或直接作为内存提供).
此Facade类中有两类fillReportXXX()方法 :
第一种类型，收到一个java.sql.Connection对象作为第三个参数.大多数情况下，报告都填充了关系数据库中的数据.这是通过 :
通过JDBC连接数据库实现的.
在报告模板中包含SQL查询.
JasperReports引擎使用传入的连接并执行SQL查询.
生成报告数据源以填写报告.
第二种类型，当需要填写的数据以其他形式提供时，接收net.sf.jasperreports.engine.JRDataSource对象.
让我们编写一份报告模板. JRXML文件(C:\tools\jasperreports-5.0.1\test\jasper_report_template.jrxml
<?xml version = "1.0" encoding = "UTF-8"?>
<!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" language = "groovy" pageWidth = "595"
pageHeight = "842" columnWidth = "555" leftMargin = "20" rightMargin = "20"
topMargin = "20" bottomMargin = "20">
<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>
<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接下来，让我们将一组Java数据对象(Java bean)传递给JasperReport Engine，以填充此编译报告.
编写一个POJO DataBean.java，它表示数据对象(Java bean).该类定义了两个String对象，即"name"和"country".将其保存到目录 C:\tools \jasperreports-5.0.1 \ test \ src \ 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;
}
}编写一个类DataBeanList.java，它具有生成java bean对象集合的业务逻辑.这将进一步传递给JasperReports引擎，以生成报告.这里我们在List中添加4个DataBean对象.将其保存到目录 C:\tools \jasperreports-5.0.1 \ test \ src \ com \ it1352.
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;
}
}写一个主类文件 JasperReportFill.java ，它获取java bean集合从类(DataBeanList)并将其传递给JasperReports引擎，以填充报告模板.将其保存到目录 C:\tools \jasperreports-5.0.1 \ test \ src \ com \ it1352.
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();
try {
JasperFillManager.fillReportToFile(
sourceFileName, parameters, beanColDataSource);
} catch (JRException e) {
e.printStackTrace();
}
}
}我们现在将编译并使用我们的常规ANT构建过程执行这些文件. build.xml文件如下所示 :
导入文件 - baseBuild.xml是从章节环境设置并且应该与build.xml放在同一目录中.
<?xml version = "1.0" encoding = "UTF-8"?> <project name = "JasperReportTest" default = "executereport" basedir = "."> <import file = "baseBuild.xml"/> <target name = "executereport" depends = "compile,compilereportdesing,run"> <echo message = "Im here"/> </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 ( executereport 是默认目标)，如下所示 :
C:\tools\jasperreports-5.0.1\test>ant -Dmain-class = com.IT屋.JasperReportFill Buildfile: C:\tools\jasperreports-5.0.1\test\build.xml compile: [javac] C:\tools\jasperreports-5.0.1\test\baseBuild.xml:27: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds [javac] Compiling 1 source file to C:\tools\jasperreports-5.0.1\test\classes 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. BUILD SUCCESSFUL Total time: 8 seconds
由于上述执行，文件 jasper_report_template .jrprint 在与 .jasper 文件相同的目录中生成(在这种情况下，它是在C:\ tools \ jasperreports-5.0.1 \ test中生成的).
