How to use Customizer Class to change the behavior of Multi Axis chart

You may ask - so what? What kind of issue may cause such disposition of the sub charts in Multi Axis chart?

Lets execute this report and check the results of this execution:

As you can see from the picture below some parts of Stacked Area chart overlap the Line charts, but you can still clearly interpret the information that was shown in the chart.

Example 2:

Stacked area charts are filled in with the values that are very close to the maximum values and they fill almost all the space in the chart:

Such visualization of the data is not so convenient becuse it's not possible to analyze the information that was represented with the Line Charts.

What can we do to change the behavior of the Line Charts in this situation?

One of the possible solutions is to write the Java code that implements the Customizer class that should change the behavior of the Line Charts(I mean show them infront of Stacked Area chart).

Below I quote the source code of such class (MultiAxisOrderCustomizer.java) which was kindly provided to me by one of our leading developers:

import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.DatasetRenderingOrder;
import org.jfree.chart.plot.Plot;
import org.jfree.chart.plot.XYPlot;

import net.sf.jasperreports.engine.JRAbstractChartCustomizer;
import net.sf.jasperreports.engine.JRChart;

public class MultiAxisOrderCustomizer extends JRAbstractChartCustomizer {
    @Override
    public void customize(JFreeChart chart, JRChart jasperChart) {
        Plot plot = chart.getPlot();
        if (plot instanceof CategoryPlot) {
            ((CategoryPlot) plot).setDatasetRenderingOrder(DatasetRenderingOrder.FORWARD);
        } else if (plot instanceof XYPlot) {
            ((XYPlot) plot).setDatasetRenderingOrder(DatasetRenderingOrder.FORWARD);
        }
    }
}

To use this Customizer Class in the report

1. give the path to this class in iReport designer

2. fill in the name of this class in the Multi Axis chart/Customizer Class property

   

Let's check the behavior of the charts after the we have applied the adjustmens that should integrate the MultiAxisOrderCustomizer in our report:

In the picture above the two line charts are shown in front of Stacked Area chart.

How to compile the source code (Windows 7)

1. Download Java JDK from the Oracle site

2. Run the windows console by executing the cmd command

3. In the windows command line, define the JAVA_HOME variable. You can do this by executing the command that I quote below

   set JAVA_HOME=c:<path to Java JDK>java
   

4. Add JAVA_HOME variable to the windows PATH variable

   set PATH=%JAVA_HOME%bin
   

5. Compile the MultiAxisOrderCustomizer (to compile this file you need two Java libraries: jfreechart.jar and jasperreports.jar)

   In my test environment was installed JasperReports Server v5.0. This distribution contains both libraries in its lib folder.

   I gave the path to these libraries in javac compiler via the -classpath key as shown below:

   javac -classpath C:jaspersjrs_500apache-tomcatwebappsjasperserver-proWEB-INFlibjfreechart-1.0.12.jar;C:jaspersjrs_500apache-tomcatwebappsjasperserver-proWEB-INFlibjasperreports-5.0.0.jar MultiAxisOrderCustomizer.java
   

   

   If everything is ok you should find MultiAxisOrderCustomizer.class file in the same directory with MultiAxisOrderCustomizer.java file.

Please find in the attachment, files.zip:

• MultipleAxisChartReport.jrxml report (this report is based on Sugarcrm database that is supplied with JasperReports Server)
• MultiAxisOrderCustomizer.java
• MultiAxisOrderCustomizer.class
• jfreechart-1.0.12.jar
• jasperreports-5.0.0.jar

Thats all. Thank you for your attention to this article :).

files.zip