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:

HashTree, HashTreeTraverser

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and 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 Detail

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 Detail

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