We have generated the JasperReport template (JRXML file) in the previous chapter. This file cannot be used directly to generate reports. It has to be compiled to JasperReport” native binary format, called Jasper file. On compiling, we transform JasperDesign object into JasperReport object −

Interface net.sf.jasperreports.engine.design.JRCompiler plays a central role during compilation. This interface has several implementations depending on the language used for report expressions, which can be written in Java, Groovy, JavaScript, or any other scripting language as long as compiler implementation can evaluate it at runtime.

We can compile JRXML file in the following two ways −

• Programmatic compilation.
• Compilation through ANT task.

Programmatic Compilation of JRXML

JasperReports API offers a facade class net.sf.jasperreports.engine.JasperCompileManager for compiling a JasperReport. This class consists of several public static methods for compiling report templates. The source of templates can be files, input streams and/or, memory objects.

The contents of the JRXML file (jasper_report_template.jrxml) are as follows. It is saved at directory C:toolsjasperreports-5.0.1test −

<?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>

The following code demonstrates compilation of the above jasper_report_template.jrxml file.

package com.tutorialspoint;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperCompileManager;

public class JasperReportCompile {

   public static void main(String[] args) {
      String sourceFileName = "C://tools/jasperreports-5.0.1/test" + 
         "/jasper_report_template.jrxml";

      System.out.println("Compiling Report Design ...");
      try {
          /**
          * Compile the report to a file name same as
          * the JRXML file name
          */
         JasperCompileManager.compileReportToFile(sourceFileName);
      } catch (JRException e) {
         e.printStackTrace();
      }
      System.out.println("Done compiling!!! ...");
   }
}

Template Compilation

As next step, let”s save above content in the file C:toolsjasperreports-5.0.1testsrccomtutorialspointJasperReportCompile.java and import the baseBuild.xml in the build.xml file as below. The baseBuild.xml already has the compile and run targets −

<?xml version = "1.0" encoding = "UTF-8"?>
<project name = "JasperReportTest" default = "run" basedir = ".">

   <import file = "baseBuild.xml"/>

</project>

Next, let”s open command line window and go to the directory where build.xml is placed. Finally, execute the command ant -Dmain-class = com.tutorialspoint.JasperReportCompile as −

C:toolsjasperreports-5.0.1test>ant -Dmain-class = com.tutorialspoint.JasperReportCompile
Buildfile: C:toolsjasperreports-5.0.1testbuild.xml
compile:
   [javac] C:toolsjasperreports-5.0.1testbaseBuild.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:toolsjasperreports-5.0.1testclasses

run:
   [echo] Runnin class : com.tutorialspoint.JasperReportCompile
   [java] Compiling Report Design ...
   [java] log4j:WARN No appenders could be found for logger
   (net.sf.jasperreports.engine.xml.JRXmlDigesterFactory).
   [java] log4j:WARN Please initialize the log4j system properly.
   [java] Done compiling!!! ...

BUILD SUCCESSFUL
Total time: 8 seconds

As a result of above compilation, you will see that template file jasper_report_template.jasper got generated in C:toolsjasperreports-5.0.1test directory.

Preview Compiled Report Template

The net.sf.jasperreports.view.JasperDesignViewer can be used to preview compiled report templates and JRXML templates.

To move further, let”s add a new target viewDesign to the above build.xml file, which will allow us to preview the compiled report. Below is the revised build.xml −

The import file – baseBuild.xml is picked from 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 = "viewDesign" basedir = ".">

   <import file = "baseBuild.xml" />
   <target name = "viewDesign" description="Design viewer is launched 
      to preview the compiled report design.">
      
      <java classname = "net.sf.jasperreports.view.JasperDesignViewer" fork = "true">
         <arg value = "-F${file.name}.jasper" />
         <classpath refid = "classpath" />
      </java>
   </target>

</project>

Let”s execute the command − ant (viewDesign is the default target) at command prompt. JasperDesignViewer window opens up displaying the Jasper file as below −

Compilation through ANT Task

As report template compilation is more like a design time job than a runtime job, JasperReport library has a custom ANT task. For certain situations, when JRXML file is created at runtime, we can”t use this ANT task. The custom ANT task is called JRC and is implemented by the class: net.sf.jasperreports.ant.JRAntCompileTask. Its syntax and behavior are very similar to the built-in <javac> ANT task.

Template Compilation

Let”s add new target compilereportdesing to our existing build.xml. Here, the source folder is specified using a nested <src> tag with the filesets. The nested source tag allows compiling report templates that are scattered through many different locations and are not grouped under a single root report source folder. Below is the revised build.xml −

<?xml version = "1.0" encoding = "UTF-8"?>
<project name = "JasperReportTest" default = "compilereportdesing" basedir = ".">
   
   <import file = "baseBuild.xml" />
   <target name = "viewDesign" description = "Design viewer is 
      launched to preview the compiled report design.">
      
      <java classname = "net.sf.jasperreports.view.JasperDesignViewer" fork = "true">
         <arg value = "-F${file.name}.jasper" />
         <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 prompt and go to the directory where build.xml is placed. Execute the command ant (compilereportdesing is the default target); Output is as follows −

C:toolsjasperreports-5.0.1test>ant
Buildfile: C:toolsjasperreports-5.0.1testbuild.xml

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:toolsjasperreports-5.0.1testjasper_report_template.jrxml ... OK.

BUILD SUCCESSFUL
Total time: 5 seconds

File jasper_report_template.jasper is generated in the file system (in our case C:toolsjasperreports-5.0.1test directory). This file is identical to the file generated programmatically by calling the net.sf.jasperreports.engine.JasperCompileManager.compileReportToFile(). We can preview this jasper file, executing ant viewDesign.