Package org.apache.commons.configuration2.tree

Class NodeHandlerDecorator<T>

java.lang.Object
org.apache.commons.configuration2.tree.NodeHandlerDecorator<T>
Type Parameters:
T - the type of the nodes supported by this handler
All Implemented Interfaces:
NodeHandler<T>
public abstract class NodeHandlerDecorator<T> extends Object implements NodeHandler<T>

An abstract base class for decorators of a NodeHandler.

This class implements all methods of the NodeHandler interface by delegating to another instance. This is convenient if specific functionality of a NodeHandler is to be adapted for a special use case. Concrete sub classes have to implement the getDecoratedNodeHandler() method to provide the underlying handler.

Since:
2.0

  • Constructor Details

  • Method Details

    • getAttributes

      public Set<String> getAttributes(T node)
      Description copied from interface: NodeHandler
      Gets an unmodifiable set with the names of all attributes of the specified node.
      Specified by:
      getAttributes in interface NodeHandler<T>
      Parameters:
      node - the node
      Returns:
      a set with the names of all attributes of this node

    • getAttributeValue

      public Object getAttributeValue(T node, String name)
      Description copied from interface: NodeHandler
      Gets the value of the specified attribute from the given node. If a concrete NodeHandler supports attributes with multiple values, result might be a collection.
      Specified by:
      getAttributeValue in interface NodeHandler<T>
      Parameters:
      node - the node
      name - the name of the attribute
      Returns:
      the value of this attribute

    • getChild

      public T getChild(T node, int index)
      Description copied from interface: NodeHandler
      Gets the child with the given index of the specified node.
      Specified by:
      getChild in interface NodeHandler<T>
      Parameters:
      node - the node
      index - the index (0-based)
      Returns:
      the child with the given index

    • getChildren

      public List<T> getChildren(T node)
      Description copied from interface: NodeHandler
      Gets an unmodifiable list with all children of the specified node.
      Specified by:
      getChildren in interface NodeHandler<T>
      Parameters:
      node - the node
      Returns:
      a list with the child nodes of this node

    • getChildren

      public List<T> getChildren(T node, String name)
      Description copied from interface: NodeHandler
      Gets an unmodifiable list of all children of the specified node with the given name.
      Specified by:
      getChildren in interface NodeHandler<T>
      Parameters:
      node - the node
      name - the name of the desired child nodes
      Returns:
      a list with all children with the given name

    • getChildrenCount

      public int getChildrenCount(T node, String name)
      Description copied from interface: NodeHandler
      Gets the number of children of the specified node with the given name. This method exists for performance reasons: for some node implementations it may be by far more efficient to count the children than to query a list of all children and determine its size. A concrete implementation can choose the most efficient way to determine the number of children. If a child name is passed in, only the children with this name are taken into account. If the name null is passed, the total number of children must be returned.
      Specified by:
      getChildrenCount in interface NodeHandler<T>
      Parameters:
      node - the node
      name - the name of the children in question (can be null for all children)
      Returns:
      the number of the selected children

    • getDecoratedNodeHandler

      protected abstract NodeHandler<T> getDecoratedNodeHandler()
      Gets the NodeHandler object that is decorated by this instance. All method calls are delegated to this object.
      Returns:
      the decorated NodeHandler

    • getMatchingChildren

      public <C> List<T> getMatchingChildren(T node, NodeMatcher<C> matcher, C criterion)
      Description copied from interface: NodeHandler
      Gets an unmodifiable list of all children of the specified node which are matched by the passed in NodeMatcher against the provided criterion. This method allows for advanced queries on a node's children.
      Specified by:
      getMatchingChildren in interface NodeHandler<T>
      Type Parameters:
      C - the type of the criterion
      Parameters:
      node - the node
      matcher - the NodeMatcher defining filter criteria
      criterion - the criterion to be matched against; this object is passed to the NodeMatcher
      Returns:
      a list with all children matched by the matcher

    • getMatchingChildrenCount

      public <C> int getMatchingChildrenCount(T node, NodeMatcher<C> matcher, C criterion)
      Description copied from interface: NodeHandler
      Gets the number of children of the specified node which are matched by the given NodeMatcher. This is a more generic version of NodeHandler.getChildrenCount(Object, String). It allows checking for arbitrary filter conditions.
      Specified by:
      getMatchingChildrenCount in interface NodeHandler<T>
      Type Parameters:
      C - the type of the criterion
      Parameters:
      node - the node
      matcher - the NodeMatcher
      criterion - the criterion to be passed to the NodeMatcher
      Returns:
      the number of matched children

    • getParent

      public T getParent(T node)
      Description copied from interface: NodeHandler
      Gets the parent of the specified node.
      Specified by:
      getParent in interface NodeHandler<T>
      Parameters:
      node - the node
      Returns:
      the parent node

    • getRootNode

      public T getRootNode()
      Description copied from interface: NodeHandler
      Gets the root node of the underlying hierarchy.
      Specified by:
      getRootNode in interface NodeHandler<T>
      Returns:
      the current root node

    • getValue

      public Object getValue(T node)
      Description copied from interface: NodeHandler
      Gets the value of the specified node.
      Specified by:
      getValue in interface NodeHandler<T>
      Parameters:
      node - the node
      Returns:
      the value of this node

    • hasAttributes

      public boolean hasAttributes(T node)
      Description copied from interface: NodeHandler
      Returns a flag whether the passed in node has any attributes.
      Specified by:
      hasAttributes in interface NodeHandler<T>
      Parameters:
      node - the node
      Returns:
      a flag whether this node has any attributes

    • indexOfChild

      public int indexOfChild(T parent, T child)
      Description copied from interface: NodeHandler
      Returns the index of the given child node in the list of children of its parent. This method is the opposite operation of NodeHandler.getChild(Object, int). This method returns 0 if the given node is the first child node with this name, 1 for the second child node and so on. If the node has no parent node or if it is an attribute, -1 is returned.
      Specified by:
      indexOfChild in interface NodeHandler<T>
      Parameters:
      parent - the parent node
      child - a child node whose index is to be retrieved
      Returns:
      the index of this child node

    • isDefined

      public boolean isDefined(T node)
      Description copied from interface: NodeHandler
      Checks whether the specified node is defined. Nodes are "defined" if they contain any data, e.g. a value, or attributes, or defined children.
      Specified by:
      isDefined in interface NodeHandler<T>
      Parameters:
      node - the node to test
      Returns:
      a flag whether the passed in node is defined

    • nodeName

      public String nodeName(T node)
      Description copied from interface: NodeHandler
      Returns the name of the specified node
      Specified by:
      nodeName in interface NodeHandler<T>
      Parameters:
      node - the node
      Returns:
      the name of this node