Visualizing Java 8

The following is a visualization of the relative size of the packages – measured in terms of the number of bytecode instructions – of Oracle JDK 1.8.0's runtime jar (rt.jar) for Mac OS X. As you can see, the java package and its subpackages contains a major part of the code. Another major package is (more or less as expected) the javax package. (JavaFX is stored in another jar and is not considered here.)

However, it is very interesting that more than half of the code belongs to packages (com and sun) that are not intended to be used by the regular Java developer.

To get more detailed information on a package and its sub-packages just left-click on the package. If you want to get more abstract information right click on the package.

The visualization was created using: JavaScript InfoVis Toolkit.

The analysis was written using the OPAL Bytecode toolkit and is shown next (5 lines of boilerplate and 12 lines for the analysis).

object InstructionStatistics extends AnalysisExecutor {

  val analysis = new Analysis[URL, BasicReport] {

    def description: String = "Collects information about the number of instructions per package."

    def analyze(project: Project[URL], parameters: Seq[String]) = {
      import scala.collection.mutable.{ HashSet, HashMap }
      // FQPN = FullyQualifiedPackageName
      val instructionsPerFQPN = HashMap.empty[String, Int]
      for {
        classFile ← project.classFiles
        packageName = classFile.thisType.packageName
        MethodWithBody(body) ← classFile.methods
      } {
        instructionsPerFQPN.update(
          packageName,
          instructionsPerFQPN.getOrElse(packageName, 0) + body.programCounters.size)
      }
      val json : String = // generate the JSON
      BasicReport(json)
    }
  }
}