All of the Professional licensing options (see here for details) include the JHawk Data viewer and the JHawk DataViewer Command line service. The Data Viewer and the Data Viewer Command Line Service both use data data exported to XML files in the JHawk Metric Interchange format. This is a summary of the data collected by JHawk which can be used to reconstitute any of the JHawk metrics. You can find out more about the features of the DataViewer here.

On this page we are going to concentrate on using the JHawk Data Viewer (and the JHawk DataViewer Command Line Service) to create motion charts.

Motion charts are a useful way to view changes in data over time. This is of particular benefit when we are examining changes in the values of metrics in a body of code over time and we'll show you this using a body of source code.

First we want to create the base XML files that we will use to create the motion chart. We can build these simply using the command line. Let's say our body of code is in the directory /source/version where version is the version of the code. We can write a simple script that uses the JHawk command line tool to build XML interchange files that include all the metrics at package, class and method level:

java -jar jhawkCommandLine.jar -f .*\.java -r -b -l pcm -s D:\source\version1 -x D:\xmlFiles\version1 -system OurCode
java -jar jhawkCommandLine.jar -f .*\.java -r -b -l pcm -s D:\source\version2 -x D:\xmlFiles\version2 -system OurCode
java -jar jhawkCommandLine.jar -f .*\.java -r -b -l pcm -s D:\source\version3 -x D:\xmlFiles\version3 -system OurCode
... etc


In this case we're going to look at 4 metrics relating to our code - Number of statements (NOS) , Maintainability (MI) , Average Cyclomatic Complexity (AVCC) and our new metric - Review Factor (see more details here). We've chosen these metrics because they are available at package and class level.

In this example we are going to use the source code of the JUnit open source project. We downloaded the source code and used the JHawk command line as described above to create the initial XML files. This gave us a summary of the metrics for each iteration of the code from JUnit 3.4 to JUnit 4.8 To do the analysis using the JHawkDataViewer we first select the files using the Select files tab. Since we are going to produce the motion chart directly from these files we don't have to analyze the files first.

In the Visualization tab we select the metrics that we want, the file name and the style of visualization then we press the 'create Visualization' button. In this case we have selected a package level motion chart for the 4 selected metrics.

Using the interactive Data Viewer is useful if you don't quite know what you want. You might try a number of different criteria (e.g. metrics, different levels (method or class) etc) until you find a representation that suits your needs.
Using the Jhawk Data Viewer Service command line allows you to automate this process once you have selected your favourite representation. So in our example above we would have done the following to create exactly the same diagram:

java -jar JHawkDataViewerService.jar "OurTests\JUnit_lp.html" "D:\JUnitSourceTests\xmlFiles" "NOS^RVF^AVCC^MI" -lp

The files that we created using both the dataviewer and the command line are available here -
The package level view and the class level view. You can use the drop-down menus to change the metric shown on the x and y axis , shown by colour and shown by relative size. Pressing the 'play' button in the bottom left hand corner will play the visualization over each of the releases. As the motion charts only operate on a time sequence each release has been assigned a date. You can find more about Motion Charts here

The Demo download includes more documentation relating to the DataViewer. You can download it here.

You may be interested in some of our other products. All have demo or trial versions. Just click on the links below to find out more -

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