org.apache.jorphan.collections
Class SearchByClass

java.lang.Object
  org.apache.jorphan.collections.SearchByClass

All Implemented Interfaces:

HashTreeTraverser

public class SearchByClass

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 StringBuffer objects, you can use the SearchByClass traverser to find all the StringBuffer 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(StringBuffer.class);
 tree.traverse(searcher);
 Iterator iter = searcher.getSearchResults().iterator();
 while (iter.hasNext()) {
  StringBuffer foundNode = (StringBuffer) iter.next();
  HashTree subTreeOfFoundNode = searcher.getSubTree(foundNode);
  //  .... do something with node and subTree...
 }
 

Version:

$Revision: 747194 $

See Also:

HashTree, HashTreeTraverser

Constructor Summary

SearchByClass()
Creates an instance of SearchByClass.

SearchByClass(Class searchClass)
Creates an instance of SearchByClass, and sets the Class to be searched for.

Method Summary

void	addNode(Object node, HashTree subTree) The tree traverses itself depth-first, calling addNode for each object it encounters as it goes.
Collection	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 Detail

SearchByClass

public SearchByClass()

Creates an instance of SearchByClass. However, without setting the Class to search for, it will be a useless object.

SearchByClass

public SearchByClass(Class searchClass)

Creates an instance of SearchByClass, and sets the Class to be searched for.

Parameters:

searchClass -

Method Detail

getSearchResults

public Collection 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)

Description copied from interface: HashTreeTraverser

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()

Description copied from interface: HashTreeTraverser

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()

Description copied from interface: HashTreeTraverser

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