Package generic.constraint

Class DecisionTree<T>

  • Type Parameters:
    T - the type of object that the constraints are checked against.
    Direct Known Subclasses:
    ProgramDecisionTree
    public class DecisionTree<T>
extends java.lang.Object
    A decisionTree is used to find property values that are determined by traversing a tree of constraints. Each node in the tree has an associated constraint. If the constraint is satisfied for a given test object, then its child nodes are tested to find more and more specific results. When either there are no children in a node or none of the children's constraints are satisfied or by traversing those that are satisfied did not result in find a property match, the current node is check to see if it has a value for the property being search. If so, that result is added as a Decision.

    There can be multiple paths where all constraints a matched resulting in multiple possible decisions.

    A non-leaf node can have properties as well, that serve as a default if it's constraint is satisfied, but not of its children is satisfied or resulted in a decision.

    • Constructor Summary

      Constructors 
      Constructor Description
      DecisionTree()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      DecisionSet getDecisionsSet​(T testObject, java.lang.String propertyName)
      Searches the decision tree for values of given property name that match the constraints within this tree.
      void loadConstraints​(ResourceFile file)
      Loads the tree from an xml constraint file.
      void loadConstraints​(java.lang.String name, java.io.InputStream stream)
      Loads the tree from an xml data contained within an input stream.
      void registerConstraintType​(java.lang.String name, java.lang.Class<? extends Constraint<T>> constraintClass)
      Registers a constraint class to be recognized from an xml constraint specification file.
      void registerPropertyName​(java.lang.String propertyName)
      Registers a property name.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • DecisionTree

        public DecisionTree()

    • Method Detail

      • getDecisionsSet

        public DecisionSet getDecisionsSet​(T testObject,
                                   java.lang.String propertyName)
        Searches the decision tree for values of given property name that match the constraints within this tree.
        Parameters:
        testObject - the object that the constraints are test against.
        propertyName - the name of the property whose values are being collected.
        Returns:
        a DecisionSet containing all the values of the given property whose path in the tree matched all the constraints for the given test object.

      • registerConstraintType

        public void registerConstraintType​(java.lang.String name,
                                   java.lang.Class<? extends Constraint<T>> constraintClass)
        Registers a constraint class to be recognized from an xml constraint specification file.
        Parameters:
        name - the name of the constraint which is also the xml tag value.
        constraintClass - the constraint type which will be initialized from the xml constraint specification file.

      • registerPropertyName

        public void registerPropertyName​(java.lang.String propertyName)
        Registers a property name. Every tag in an xml constraint file (except the root tag which is unused) must be either a constraint name or a property name.
        Parameters:
        propertyName - the name of a valid property to be expected in an xml constraints file.

      • loadConstraints

        public void loadConstraints​(java.lang.String name,
                            java.io.InputStream stream)
                     throws java.io.IOException,
                            XmlParseException
        Loads the tree from an xml data contained within an input stream. Note: this method can be called multiple times, with each call appending to the existing tree.
        Parameters:
        name - the name of the input source so that decisions can be traced back to the appropriate xml constraints source.
        stream - the InputStream from which to read an xml constraints specification.
        Throws:
        java.io.IOException - if an I/O problem occurs reading from the stream.
        XmlParseException - if the XML is not property formatted or a tag that is not a constraint name or property name is encountered.

      • loadConstraints

        public void loadConstraints​(ResourceFile file)
                     throws java.io.FileNotFoundException,
                            java.io.IOException,
                            XmlParseException
        Loads the tree from an xml constraint file. Note: this method can be called multiple times, with each call appending to the existing tree.
        Parameters:
        file - the file that contains the xml for the constraint.
        Throws:
        java.io.IOException - if an I/O problem occurs reading from the stream.
        XmlParseException - if the XML is not property formatted or a tag that is not a constraint name or property name is encountered.
        java.io.FileNotFoundException