Package generic.constraint

Class DecisionTree<T>

java.lang.Object
generic.constraint.DecisionTree<T>
Type Parameters:
T - the type of object that the constraints are checked against.
Direct Known Subclasses:
ProgramDecisionTree
public class DecisionTree<T> extends 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 Details

    • DecisionTree

      public DecisionTree()

  • Method Details

    • getDecisionsSet

      public DecisionSet getDecisionsSet(T testObject, 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(String name, 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(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(String name, InputStream stream) throws 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:
      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 FileNotFoundException, 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:
      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.
      FileNotFoundException