Class Node

java.lang.Object
groovy.util.Node
All Implemented Interfaces:
Serializable
public class Node extends Object implements Serializable
Represents an arbitrary tree node which can be used for structured metadata or any arbitrary XML-like tree. A node can have a name, a value and an optional Map of attributes. Typically the name is a String and a value is either a String or a List of other Nodes, though the types are extensible to provide a flexible structure, e.g. you could use a QName as the name which includes a namespace URI and a local name. Or a JMX ObjectName etc. So this class can represent metadata like {foo a=1 b="abc"} or nested metadata like {foo a=1 b="123" { bar x=12 text="hello" }}
Author:
James Strachan, Paul King
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    Node(Node parent, Object name)
    Creates a new Node named name and if a parent is supplied, adds the newly created node as a child of the parent.
    Node(Node parent, Object name, Object value)
    Creates a new Node named name with value value and if a parent is supplied, adds the newly created node as a child of the parent.
    Node(Node parent, Object name, Map attributes)
    Creates a new Node named name with attributes specified in the attributes Map.
    Node(Node parent, Object name, Map attributes, Object value)
    Creates a new Node named name with value value and with attributes specified in the attributes Map.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    append(Node child)
    Appends a child to the current node.
    Node
    appendNode(Object name)
    Creates a new node as a child of the current node.
    Node
    appendNode(Object name, Object value)
    Creates a new node as a child of the current node.
    Node
    appendNode(Object name, Map attributes)
    Creates a new node as a child of the current node.
    Node
    appendNode(Object name, Map attributes, Object value)
    Creates a new node as a child of the current node.
    Object
    attribute(Object key)
    Provides lookup of attributes by key.
    Map
    attributes()
    Returns a Map of the attributes of the node or an empty Map if the node does not have any attributes.
    List
    breadthFirst()
    Provides a collection of all the nodes in the tree using a breadth-first traversal.
    List
    children()
    Returns a List of the nodes children.
    List
    depthFirst()
    Provides a collection of all the nodes in the tree using a depth first traversal.
    Object
    get(String key)
    Provides lookup of elements by non-namespaced name
    NodeList
    getAt(QName name)
    Provides lookup of elements by QName.
    Iterator
    iterator()
    Returns an Iterator of the children of the node.
    Object
    name()
    Returns an Object representing the name of the node.
    Node
    parent()
    Returns the parent of the node.
    void
    plus(Closure c)
    Adds sibling nodes (defined using builder-style notation via a Closure) after the current node.
    void
    print(PrintWriter out)
    Writes the node to the specified PrintWriter.
    boolean
    remove(Node child)
    Removes a child of the current node.
    Node
    replaceNode(Closure c)
    Replaces the current node with nodes defined using builder-style notation via a Closure.
    protected static void
    setMetaClass(MetaClass metaClass, Class nodeClass)
    Extension point for subclasses to override the metaclass.
    protected void
    setParent(Node parent)
    Adds or replaces the parent of the node.
    void
    setValue(Object value)
    Adds or replaces the value of the node.
    String
    text()
    Returns the textual representation of the current node and all its child nodes.
    String
    toString()
     
    Object
    value()
    Returns an Object representing the value of the node.

    Methods inherited from class Object

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

  • Constructor Details

    • Node

      public Node(Node parent, Object name)
      Creates a new Node named name and if a parent is supplied, adds the newly created node as a child of the parent.
      Parameters:
      parent - the parent node or null if no parent
      name - the name of the node

    • Node

      public Node(Node parent, Object name, Object value)
      Creates a new Node named name with value value and if a parent is supplied, adds the newly created node as a child of the parent.
      Parameters:
      parent - the parent node or null if no parent
      name - the name of the node
      value - the Node value, e.g. some text but in general any Object

    • Node

      public Node(Node parent, Object name, Map attributes)
      Creates a new Node named name with attributes specified in the attributes Map. If a parent is supplied, the newly created node is added as a child of the parent.
      Parameters:
      parent - the parent node or null if no parent
      name - the name of the node
      attributes - a Map of name-value pairs

    • Node

      public Node(Node parent, Object name, Map attributes, Object value)
      Creates a new Node named name with value value and with attributes specified in the attributes Map. If a parent is supplied, the newly created node is added as a child of the parent.
      Parameters:
      parent - the parent node or null if no parent
      name - the name of the node
      attributes - a Map of name-value pairs
      value - the Node value, e.g. some text but in general any Object

  • Method Details

    • append

      public boolean append(Node child)
      Appends a child to the current node.
      Parameters:
      child - the child to append
      Returns:
      true

    • remove

      public boolean remove(Node child)
      Removes a child of the current node.
      Parameters:
      child - the child to remove
      Returns:
      true if the param was a child of the current node

    • appendNode

      public Node appendNode(Object name, Map attributes)
      Creates a new node as a child of the current node.
      Parameters:
      name - the name of the new node
      attributes - the attributes of the new node
      Returns:
      the newly created Node

    • appendNode

      public Node appendNode(Object name)
      Creates a new node as a child of the current node.
      Parameters:
      name - the name of the new node
      Returns:
      the newly created Node

    • appendNode

      public Node appendNode(Object name, Object value)
      Creates a new node as a child of the current node.
      Parameters:
      name - the name of the new node
      value - the value of the new node
      Returns:
      the newly created Node

    • appendNode

      public Node appendNode(Object name, Map attributes, Object value)
      Creates a new node as a child of the current node.
      Parameters:
      name - the name of the new node
      attributes - the attributes of the new node
      value - the value of the new node
      Returns:
      the newly created Node

    • replaceNode

      public Node replaceNode(Closure c)
      Replaces the current node with nodes defined using builder-style notation via a Closure.
      Parameters:
      c - A Closure defining the new nodes using builder-style notation.
      Returns:
      the last appended node

    • plus

      public void plus(Closure c)
      Adds sibling nodes (defined using builder-style notation via a Closure) after the current node.
      Parameters:
      c - A Closure defining the new sibling nodes to add using builder-style notation.

    • setMetaClass

      protected static void setMetaClass(MetaClass metaClass, Class nodeClass)
      Extension point for subclasses to override the metaclass. The default one supports the property and @ attribute notations.
      Parameters:
      metaClass - the original metaclass
      nodeClass - the class whose metaclass we wish to override (this class or a subclass)

    • text

      public String text()
      Returns the textual representation of the current node and all its child nodes.
      Returns:
      the text value of the node including child text

    • iterator

      public Iterator iterator()
      Returns an Iterator of the children of the node.
      Returns:
      the iterator of the nodes children

    • children

      public List children()
      Returns a List of the nodes children.
      Returns:
      the nodes children

    • attributes

      public Map attributes()
      Returns a Map of the attributes of the node or an empty Map if the node does not have any attributes.
      Returns:
      the attributes of the node

    • attribute

      public Object attribute(Object key)
      Provides lookup of attributes by key.
      Parameters:
      key - the key of interest
      Returns:
      the attribute matching the key or null if no match exists

    • name

      public Object name()
      Returns an Object representing the name of the node.
      Returns:
      the name or null if name is empty

    • value

      public Object value()
      Returns an Object representing the value of the node.
      Returns:
      the value or null if value is empty

    • setValue

      public void setValue(Object value)
      Adds or replaces the value of the node.
      Parameters:
      value - the new value of the node

    • parent

      public Node parent()
      Returns the parent of the node.
      Returns:
      the parent or null for the root node

    • setParent

      protected void setParent(Node parent)
      Adds or replaces the parent of the node.
      Parameters:
      parent - the new parent of the node

    • get

      public Object get(String key)
      Provides lookup of elements by non-namespaced name
      Parameters:
      key - the name (or shortcut key) of the node(s) of interest
      Returns:
      the nodes which match key

    • getAt

      public NodeList getAt(QName name)
      Provides lookup of elements by QName.
      Parameters:
      name - the QName of interest
      Returns:
      the nodes matching name

    • depthFirst

      public List depthFirst()
      Provides a collection of all the nodes in the tree using a depth first traversal.
      Returns:
      the list of (depth-first) ordered nodes

    • breadthFirst

      public List breadthFirst()
      Provides a collection of all the nodes in the tree using a breadth-first traversal.
      Returns:
      the list of (breadth-first) ordered nodes

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • print

      public void print(PrintWriter out)
      Writes the node to the specified PrintWriter.
      Parameters:
      out - the writer receiving the output