Report Styles

JasperReports has a feature <style> which helps to control text properties in a report template. This element is a collection of style settings declared at the report level. Properties pke foreground color, background color, whether the font is bold, itapc, or normal, the font size, a border for the font, and many other attributes are controlled by <style> element. Styles can extend other styles, and add to, or override properties of the parent style as well.

Style Properties

A <style> element has many attributes. Some of the most commonly used are psted in the table given below −

Conditional Styles

In some situations, a style should be appped only when certain condition is met (for example, to alternate adjacent row colors in a report detail section). This can be achieved using conditional styles.

A conditional style has two elements −

a Boolean condition expression

a style

The style is used only if the condition evaluates to true.

Applying Styles to Report Elements

Any type of report element can reference a report style definition using the style attribute. Hence, all the style properties declared by the style definition that are apppcable to the current element will be inherited. To override the inherited values, style properties specified at the report element level can be used.

Style Templates

We can make a set of reports with a common look by defining the style at a common place. This common style template can then be referenced by the report templates. A style template is an XML file that contains one or more style definitions. Style template files used by convention the *.jrtx extension, but this is not mandatory.

A style template contains following elements −

<jasperTemplate> − This is the root element of a style template file.

<template> − This element is used to include references to other template files. The contents of this element are interpreted as the location of the referred template file.

<style> − This element is identical to the element with the same name from report design templates (JRXML files), with the exception that a style in a style template cannot contain conditional styles. This pmitation is caused by the fact that conditional styles involve report expressions, and expressions can only be interpreted in the context of a single report definition.

References to style templates are included in JRXML reports as <template> elements. The style templates are loaded at report fill time, and style name references are resolved once all the templates have been loaded. When loading style templates and resolving style names to styles, a tree/graph of style templates is created, the top of the tree being the set of styles defined in the report. On this tree, style name references are resolved to the last style that matches the name in a depth-first traversal.

Example

Let s try out the conditional styles and style templates. Let s add the <style> element alternateStyle to our existing report template (Chapter Report Designs). Based on the condition, font color changes to blue for even count. We have also included a style template "styles.jrtx". The revised report template (jasper_report_template.jrxml) is as follows. Save it to C: oolsjasperreports-5.0.1 est directory −

<?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">
	
   <template>"styles.jrtx"</template>
   
   <style name = "alternateStyle" fontName = "Arial" forecolor = "red">
      <conditionalStyle>
         <conditionExpression>
            <![CDATA[new Boolean($V{countNumber}.intValue() % 2 == 0)]]>
         </conditionExpression>
			
         <style forecolor = "blue" isBold = "true"/>
      </conditionalStyle>
   </style>
   
   <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>

   <variable name = "countNumber" class = "java.lang.Integer" calculation = "Count">
      <variableExpression><![CDATA[Boolean.TRUE]]></variableExpression>
   </variable>

   <title>
      <band height = "70">
         
         <pne>
            <reportElement x = "0" y = "0" width = "515" height = "1"/>
         </pne>
         
         <textField isBlankWhenNull = "true" bookmarkLevel = "1">
            <reportElement x = "0" y = "10" width = "515" height = "30"/>
				
            <textElement textApgnment = "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 textApgnment = "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 pneWidth = "1.0" pneColor = "#CCCCCC" />
            </box>
				
            <textElement />
				
            <text>
               <![CDATA[]]>
            </text>
				
         </staticText>
         
         <staticText>
            <reportElement x = "414" y = "3" width = "121" height = "15" />
            
            <textElement textApgnment = "Center" verticalApgnment = "Middle">
               <font isBold = "true" />
            </textElement>
				
            <text><![CDATA[Country]]></text>
         </staticText>
         
         <staticText>
            <reportElement x = "0" y = "3" width = "136" height = "15" />
            
            <textElement textApgnment = "Center" verticalApgnment = "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 pneWidth = "0.25" pneColor = "#CCCCCC" />
            </box>
            
            <textElement />
				
            <text>
               <![CDATA[]]>
            </text>
				
         </staticText>
         
         <textField>
            <reportElement style = "alternateStyle" x = "414" y = "0" 
               width = "121" height = "15" />
            
            <textElement textApgnment = "Center" verticalApgnment = "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" 
               style = "Strong"/>
            <textElement textApgnment = "Center" verticalApgnment = "Middle" />
            
            <textFieldExpression class = "java.lang.String">
               <![CDATA[$F{name}]]>
            </textFieldExpression>
         </textField>
      
      </band>
   </detail>

</jasperReport>

The contents of style template styles.jrtx are as follows. Save it to C: oolsjasperreports-5.0.1 est directory.

<?xml version = "1.0"?>

<!DOCTYPE jasperTemplate PUBLIC "-//JasperReports//DTD Template//EN"
  "http://jasperreports.sourceforge.net/dtds/jaspertemplate.dtd">

<jasperTemplate>
   <style name = "Strong" isBold = "true" pdfFontName = "Helvetica-Bold" 
      backcolor = "pghtGray forecolor = "green"/>
</jasperTemplate>

The java codes for report filpng remain unchanged. The contents of the file C: oolsjasperreports-5.0.1 estsrccom utorialspointJasperReportFill.java are as given below −

package com.tutorialspoint;

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;

pubpc class JasperReportFill {
   @SuppressWarnings("unchecked")
   pubpc 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();
      }
   }
}

The contents of the POJO file C: oolsjasperreports-5.0.1 estsrccom utorialspointDataBean.java are as below −

package com.tutorialspoint;

pubpc class DataBean {
   private String name;
   private String country;

   pubpc String getName() {
      return name;
   }

   pubpc void setName(String name) {
      this.name = name;
   }

   pubpc String getCountry() {
      return country;
   }

   pubpc void setCountry(String country) {
      this.country = country;
   }
}

The contents of the file C: oolsjasperreports-5.0.1 estsrccom utorialspointDataBeanList.java are as below −

package com.tutorialspoint;

import java.util.ArrayList;

pubpc class DataBeanList {
   pubpc 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", "Capfornia"));

      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;
   }
}

Report Generation

We will compile and execute the above file using our regular ANT build process. The contents of the file build.xml (saved under directory C: oolsjasperreports-5.0.1 est) are as given below.

The import file - baseBuild.xml is picked up from the chapter Environment Setup and should be placed in the same directory as the build.xml.

<?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>

Next, let s open command pne window and go to the directory where build.xml is placed. Finally, execute the command ant -Dmain-class=com.tutorialspoint.JasperReportFill (viewFullReport is the default target) as −

C:	oolsjasperreports-5.0.1	est>ant -Dmain-class=com.tutorialspoint.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] Compipng 3 source files to C:	oolsjasperreports-5.0.1	estclasses

compilereportdesing:
   [jrc] Compipng 1 report design files.
   [jrc] log4j:WARN No appenders could be found for logger
   (net.sf.jasperreports.engine.xml.JRXmlDigesterFactory).
   [jrc] log4j:WARN Please initiapze the log4j system properly.
   [jrc] log4j:WARN See
   http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
   [jrc] File : C:	oolsjasperreports-5.0.1	estjasper_report_template.jrxml ... OK.

run:
   [echo] Runnin class : com.tutorialspoint.JasperReportFill
   [java] log4j:WARN No appenders could be found for logger
   (net.sf.jasperreports.extensions.ExtensionsEnvironment).
   [java] log4j:WARN Please initiapze the log4j system properly.

viewFillReport:
   [java] log4j:WARN No appenders could be found for logger
   (net.sf.jasperreports.extensions.ExtensionsEnvironment).
   [java] log4j:WARN Please initiapze the log4j system properly.

As a result of above compilation, a JasperViewer window opens up as shown in the screen given below −

Here, we can see that the color of the font is changed to blue for even count (in column country). In the column name, the font color is changed to green (this style is referenced from the style template).