Package org.apache.jorphan.collections

Class SearchByClass<T>

java.lang.Object
org.apache.jorphan.collections.SearchByClass<T>
Type Parameters:
T - Class that should be searched for
All Implemented Interfaces:
HashTreeTraverser
public class SearchByClass<T> extends Object implements HashTreeTraverser
Useful for finding all nodes in the tree that represent objects of a particular type. For instance, if your tree contains all strings, and a few StringBuilder objects, you can use the SearchByClass traverser to find all the StringBuilder objects in your tree.

Usage is simple. Given a HashTree object "tree", and a SearchByClass object: 

 HashTree tree = new HashTree();
 // ... tree gets filled with objects
 SearchByClass searcher = new SearchByClass(StringBuilder.class);
 tree.traverse(searcher);
 Iterator iter = searcher.getSearchResults().iterator();
 while (iter.hasNext()) {
     StringBuilder foundNode = (StringBuilder) iter.next();
     HashTree subTreeOfFoundNode = searcher.getSubTree(foundNode);
     // .... do something with node and subTree...
 }
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    SearchByClass(Class<T> searchClass)
    Creates an instance of SearchByClass, and sets the Class to be searched for.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    addNode(Object node, HashTree subTree)
    The tree traverses itself depth-first, calling addNode for each object it encounters as it goes.
    Collection<T>
    getSearchResults()
    After traversing the HashTree, call this method to get a collection of the nodes that were found.
    HashTree
    getSubTree(Object root)
    Given a specific found node, this method will return the sub tree of that node.
    void
    processPath()
    Process path is called when a leaf is reached.
    void
    subtractNode()
    Indicates traversal has moved up a step, and the visitor should remove the top node from its stack structure.

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • SearchByClass

      public SearchByClass(Class<T> searchClass)
      Creates an instance of SearchByClass, and sets the Class to be searched for.
      Parameters:
      searchClass - class to be searched for

  • Method Details

    • getSearchResults

      public Collection<T> getSearchResults()
      After traversing the HashTree, call this method to get a collection of the nodes that were found.
      Returns:
      Collection All found nodes of the requested type

    • getSubTree

      public HashTree getSubTree(Object root)
      Given a specific found node, this method will return the sub tree of that node.
      Parameters:
      root - the node for which the sub tree is requested
      Returns:
      HashTree

    • addNode

      public void addNode(Object node, HashTree subTree)
      The tree traverses itself depth-first, calling addNode for each object it encounters as it goes. This is a callback method, and should not be called except by a HashTree during traversal.
      Specified by:
      addNode in interface HashTreeTraverser
      Parameters:
      node - the node currently encountered
      subTree - the HashTree under the node encountered

    • subtractNode

      public void subtractNode()
      Indicates traversal has moved up a step, and the visitor should remove the top node from its stack structure. This is a callback method, and should not be called except by a HashTree during traversal.
      Specified by:
      subtractNode in interface HashTreeTraverser

    • processPath

      public void processPath()
      Process path is called when a leaf is reached. If a visitor wishes to generate Lists of path elements to each leaf, it should keep a Stack data structure of nodes passed to it with addNode, and removing top items for every HashTreeTraverser.subtractNode() call. This is a callback method, and should not be called except by a HashTree during traversal.
      Specified by:
      processPath in interface HashTreeTraverser