Package org.simpleframework.xml.core

Class SignatureCreator

  • All Implemented Interfaces:
    Creator
    class SignatureCreator
extends java.lang.Object
implements Creator
    The Instantiator object is used to represent an single constructor within an object. It contains the actual constructor as well as the list of parameters. Each instantiator will score its weight when given a Criteria object. This allows the deserialization process to find the most suitable one to use when instantiating an object.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private java.util.List<Parameter> list
      This is the list of parameters in the order of declaration.
      private Signature signature
      This is the map that contains the parameters to be used.
      private java.lang.Class type
      This is the type represented by the creator instance.

    • Constructor Summary

      Constructors 
      Constructor Description
      SignatureCreator​(Signature signature)
      Constructor for the Instantiator object.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private double getAdjustment​(double score)
      This will use a slight adjustment to ensure that if there are many constructors with a 100% match on parameters, the one with the most values to be injected wins.
      java.lang.Object getInstance()
      This is used to instantiate the object using the default no argument constructor.
      java.lang.Object getInstance​(Criteria criteria)
      This is used to instantiate the object using a constructor that takes deserialized objects as arguments.
      private double getPercentage​(Criteria criteria)
      This is used to determine what percentage of available values can be injected in to a constructor.
      double getScore​(Criteria criteria)
      This is used to score this Instantiator object so that it can be weighed amongst other constructors.
      Signature getSignature()
      This is the signature associated with the creator.
      java.lang.Class getType()
      This is the type associated with the Creator object.
      private java.lang.Object getVariable​(Criteria criteria, int index)
      This is used to acquire a variable from the criteria provided.
      java.lang.String toString()
      This is used to acquire a descriptive name for the instantiator.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • list

        private final java.util.List<Parameter> list
        This is the list of parameters in the order of declaration.

      • signature

        private final Signature signature
        This is the map that contains the parameters to be used.

      • type

        private final java.lang.Class type
        This is the type represented by the creator instance.

    • Constructor Detail

      • SignatureCreator

        public SignatureCreator​(Signature signature)
        Constructor for the Instantiator object. This is used to create a factory like object used for instantiating objects. Each instantiator will score its suitability using the parameters it is provided.
        Parameters:
        signature - this is the signature that contains parameters

    • Method Detail

      • getType

        public java.lang.Class getType()
        This is the type associated with the Creator object. All instances returned from this creator will be of this type.
        Specified by:
        getType in interface Creator
        Returns:
        this returns the type associated with this creator

      • getSignature

        public Signature getSignature()
        This is the signature associated with the creator. The signature contains all the parameters associated with the creator as well as the constructor that this represents. Exposing the signature allows the creator to be validated.
        Specified by:
        getSignature in interface Creator
        Returns:
        this is the signature associated with the creator

      • getInstance

        public java.lang.Object getInstance()
                             throws java.lang.Exception
        This is used to instantiate the object using the default no argument constructor. If for some reason the object can not be instantiated then this will throw an exception with the reason.
        Specified by:
        getInstance in interface Creator
        Returns:
        this returns the object that has been instantiated
        Throws:
        java.lang.Exception

      • getInstance

        public java.lang.Object getInstance​(Criteria criteria)
                             throws java.lang.Exception
        This is used to instantiate the object using a constructor that takes deserialized objects as arguments. The object that have been deserialized can be taken from the Criteria object which contains the deserialized values.
        Specified by:
        getInstance in interface Creator
        Parameters:
        criteria - this contains the criteria to be used
        Returns:
        this returns the object that has been instantiated
        Throws:
        java.lang.Exception

      • getVariable

        private java.lang.Object getVariable​(Criteria criteria,
                                     int index)
                              throws java.lang.Exception
        This is used to acquire a variable from the criteria provided. In order to match the constructor correctly this will check to see if the if the parameter is required. If it is required then there must be a non null value or an exception is thrown.
        Parameters:
        criteria - this is used to acquire the parameter value
        index - this is the index to acquire the value for
        Returns:
        the value associated with the specified parameter
        Throws:
        java.lang.Exception

      • getScore

        public double getScore​(Criteria criteria)
                throws java.lang.Exception
        This is used to score this Instantiator object so that it can be weighed amongst other constructors. The instantiator that scores the highest is the one that is used for instantiation.

        If any read only element or attribute is not a parameter in the constructor then the constructor is discounted. This is because there is no way to set the read only entity without a constructor injection in to the instantiated object.

        Specified by:
        getScore in interface Creator
        Parameters:
        criteria - this contains the criteria to be used
        Returns:
        this returns the score based on the criteria provided
        Throws:
        java.lang.Exception

      • getPercentage

        private double getPercentage​(Criteria criteria)
                      throws java.lang.Exception
        This is used to determine what percentage of available values can be injected in to a constructor. Calculating the percentage in this manner ensures that the best possible fit will be used to construct the object. This also allows the object to define what defaults it wishes to set for the values.

        This will use a slight adjustment to ensure that if there are many constructors with a 100% match on parameters, the one with the most values to be injected wins. This ensures the most desirable constructor is chosen each time.

        Parameters:
        criteria - this is the criteria object containing values
        Returns:
        this returns the percentage match for the values
        Throws:
        java.lang.Exception

      • getAdjustment

        private double getAdjustment​(double score)
        This will use a slight adjustment to ensure that if there are many constructors with a 100% match on parameters, the one with the most values to be injected wins. This ensures the most desirable constructor is chosen each time.
        Parameters:
        score - this is the score from the parameter matching
        Returns:
        an adjusted score to account for the signature size

      • toString

        public java.lang.String toString()
        This is used to acquire a descriptive name for the instantiator. Providing a name is useful in debugging and when exceptions are thrown as it describes the constructor the instantiator represents.
        Overrides:
        toString in class java.lang.Object
        Returns:
        this returns the name of the constructor to be used