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

    All Methods Instance Methods Concrete Methods
    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`

Copyright © 1998-2022 Apache Software Foundation. All Rights Reserved.