Package jdepend.framework

Class JDepend

  • public class JDepend
extends java.lang.Object
    The JDepend class analyzes directories of Java class files and generates the following metrics for each Java package.

    • Afferent Coupling (Ca)

      The number of packages that depend upon the classes within the analyzed package.

    • Efferent Coupling (Ce)

      The number of packages that the classes in the analyzed package depend upon.

    • Abstractness (A)

      The ratio of the number of abstract classes (and interfaces) in the analyzed package to the total number of classes in the analyzed package.

      The range for this metric is 0 to 1, with A=0 indicating a completely concrete package and A=1 indicating a completely abstract package.

    • Instability (I)

      The ratio of efferent coupling (Ce) to total coupling (Ce + Ca) such that I = Ce / (Ce + Ca).

      The range for this metric is 0 to 1, with I=0 indicating a completely stable package and I=1 indicating a completely instable package.

    • Distance from the Main Sequence (D)

      The perpendicular distance of a package from the idealized line A + I = 1. A package coincident with the main sequence is optimally balanced with respect to its abstractness and stability. Ideal packages are either completely abstract and stable (x=0, y=1) or completely concrete and instable (x=1, y=0).

      The range for this metric is 0 to 1, with D=0 indicating a package that is coincident with the main sequence and D=1 indicating a package that is as far from the main sequence as possible.

    • Package Dependency Cycle

      Package dependency cycles are reported along with the paths of packages participating in package dependency cycles.

    These metrics are hereafter referred to as the "Martin Metrics", as they are credited to Robert Martin (Object Mentor Inc.) and referenced in the book "Designing Object Oriented C++ Applications using the Booch Method", by Robert C. Martin, Prentice Hall, 1995.

    Example API use: 

     JDepend jdepend = new JDepend();
 jdepend.addDirectory("/path/to/classes");
 Collection packages = jdepend.analyze();
 
 Iterator i = packages.iterator();
 while (i.hasNext()) {
     JavaPackage jPackage = (JavaPackage) i.next();
     String name = jPackage.getName();
     int Ca = jPackage.afferentCoupling();
     int Ce = jPackage.efferentCoupling();
     float A = jPackage.abstractness();
     float I = jPackage.instability();
     float D = jPackage.distance();
     boolean b = jPackage.containsCycle();
 }

    This class is the data model used by the jdepend.textui.JDepend and jdepend.swingui.JDepend views.

    Author:
    Mike Clark, Clarkware Consulting, Inc.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addDirectory​(java.lang.String name)
      Adds the specified directory name to the collection of directories to be analyzed.
      JavaPackage addPackage​(java.lang.String name)
      Adds the specified Java package name to the collection of analyzed packages.
      void addPackage​(JavaPackage pkg)
      Adds the specified Java package to the collection of analyzed packages.
      void addPackages​(java.util.Collection packages)
      Adds the specified collection of packages to the collection of analyzed packages.
      void addParseListener​(ParserListener listener)
      Registers the specified parser listener.
      java.util.Collection analyze()
      Analyzes the registered directories and returns the collection of analyzed packages.
      void analyzeInnerClasses​(boolean b)
      Determines whether inner classes are analyzed.
      boolean containsCycles()
      Indicates whether the packages contain one or more dependency cycles.
      int countClasses()
      Returns the number of registered Java classes to be analyzed.
      int countPackages()
      Returns the number of analyzed Java packages.
      boolean dependencyMatch​(DependencyConstraint constraint)
      Indicates whether the analyzed packages match the specified dependency constraint.
      PackageFilter getFilter()  
      JavaPackage getPackage​(java.lang.String name)
      Returns the analyzed package of the specified name.
      java.util.Collection getPackages()
      Returns the collection of analyzed packages.
      void setComponents​(java.lang.String components)
      Sets the list of components.
      void setFilter​(PackageFilter filter)  

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • JDepend

        public JDepend()

    • Method Detail

      • analyze

        public java.util.Collection analyze()
        Analyzes the registered directories and returns the collection of analyzed packages.
        Returns:
        Collection of analyzed packages.

      • addDirectory

        public void addDirectory​(java.lang.String name)
                  throws java.io.IOException
        Adds the specified directory name to the collection of directories to be analyzed.
        Parameters:
        name - Directory name.
        Throws:
        java.io.IOException - If the directory is invalid.

      • setComponents

        public void setComponents​(java.lang.String components)
        Sets the list of components.
        Parameters:
        components - Comma-separated list of components.

      • analyzeInnerClasses

        public void analyzeInnerClasses​(boolean b)
        Determines whether inner classes are analyzed.
        Parameters:
        b - true to analyze inner classes; false otherwise.

      • getPackages

        public java.util.Collection getPackages()
        Returns the collection of analyzed packages.
        Returns:
        Collection of analyzed packages.

      • getPackage

        public JavaPackage getPackage​(java.lang.String name)
        Returns the analyzed package of the specified name.
        Parameters:
        name - Package name.
        Returns:
        Package, or null if the package was not analyzed.

      • countPackages

        public int countPackages()
        Returns the number of analyzed Java packages.
        Returns:
        Number of Java packages.

      • countClasses

        public int countClasses()
        Returns the number of registered Java classes to be analyzed.
        Returns:
        Number of classes.

      • containsCycles

        public boolean containsCycles()
        Indicates whether the packages contain one or more dependency cycles.
        Returns:
        true if one or more dependency cycles exist.

      • dependencyMatch

        public boolean dependencyMatch​(DependencyConstraint constraint)
        Indicates whether the analyzed packages match the specified dependency constraint.
        Returns:
        true if the packages match the dependency constraint

      • addParseListener

        public void addParseListener​(ParserListener listener)
        Registers the specified parser listener.
        Parameters:
        listener - Parser listener.

      • addPackage

        public JavaPackage addPackage​(java.lang.String name)
        Adds the specified Java package name to the collection of analyzed packages.
        Parameters:
        name - Java package name.
        Returns:
        Added Java package.

      • addPackages

        public void addPackages​(java.util.Collection packages)
        Adds the specified collection of packages to the collection of analyzed packages.
        Parameters:
        packages - Collection of packages.

      • addPackage

        public void addPackage​(JavaPackage pkg)
        Adds the specified Java package to the collection of analyzed packages.
        Parameters:
        pkg - Java package.