Class TreeStrategy

  • All Implemented Interfaces:
    Strategy

    public class TreeStrategy
    extends java.lang.Object
    implements Strategy
    The TreeStrategy object is used to provide a simple strategy for handling object graphs in a tree structure. This does not resolve cycles in the object graph. This will make use of the specified class attribute to resolve the class to use for a given element during the deserialization process. For the serialization process the "class" attribute will be added to the element specified. If there is a need to use an attribute name other than "class" then the name of the attribute to use can be specified.
    Author:
    Niall Gallagher
    See Also:
    CycleStrategy
    • Constructor Summary

      Constructors 
      Constructor Description
      TreeStrategy()
      Constructor for the TreeStrategy object.
      TreeStrategy​(java.lang.String label, java.lang.String length)
      Constructor for the TreeStrategy object.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Value read​(Type type, NodeMap node, java.util.Map map)
      This is used to resolve and load a class for the given element.
      boolean write​(Type type, java.lang.Object value, NodeMap node, java.util.Map map)
      This is used to attach a attribute to the provided element that is used to identify the class.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • TreeStrategy

        public TreeStrategy()
        Constructor for the TreeStrategy object. This is used to create a strategy that can resolve and load class objects for deserialization using a "class" attribute. Also for serialization this will add the appropriate "class" value.
      • TreeStrategy

        public TreeStrategy​(java.lang.String label,
                            java.lang.String length)
        Constructor for the TreeStrategy object. This is used to create a strategy that can resolve and load class objects for deserialization using the specified attribute. The attribute value can be any legal XML attribute name.
        Parameters:
        label - this is the name of the attribute to use
        length - this is used to determine the array length
    • Method Detail

      • read

        public Value read​(Type type,
                          NodeMap node,
                          java.util.Map map)
                   throws java.lang.Exception
        This is used to resolve and load a class for the given element. Resolution of the class to used is done by inspecting the XML element provided. If there is a "class" attribute on the element then its value is used to resolve the class to use. If no such attribute exists on the element this returns null.
        Specified by:
        read in interface Strategy
        Parameters:
        type - this is the type of the XML element expected
        node - this is the element used to resolve an override
        map - this is used to maintain contextual information
        Returns:
        returns the class that should be used for the object
        Throws:
        java.lang.Exception - thrown if the class cannot be resolved
      • write

        public boolean write​(Type type,
                             java.lang.Object value,
                             NodeMap node,
                             java.util.Map map)
        This is used to attach a attribute to the provided element that is used to identify the class. The attribute name is "class" and has the value of the fully qualified class name for the object provided. This will only be invoked if the object class is different from the field class.
        Specified by:
        write in interface Strategy
        Parameters:
        type - this is the declared class for the field used
        value - this is the instance variable being serialized
        node - this is the element used to represent the value
        map - this is used to maintain contextual information
        Returns:
        this returns true if serialization is complete