CollectNodesVisitor (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.compile.CollectNodesVisitor<T>

All Implemented Interfaces:

Visitor
```
public class CollectNodesVisitor<T extends Visitable>
extends java.lang.Object
implements Visitor
```
Collect all nodes of the designated type to be returned in a list.
Can find any type of node -- the class or class name of the target node is passed in as a constructor parameter.

Field Summary

Fields
Modifier and Type Field Description

private java.lang.Class<T> nodeClass

private java.util.List<T> nodeList

private java.lang.Class<? extends Visitable> skipOverClass

Fields
Modifier and Type	Field	Description
`private java.lang.Class<T>`	`nodeClass`
`private java.util.List<T>`	`nodeList`
`private java.lang.Class<? extends Visitable>`	`skipOverClass`

Constructor Summary

Constructors
Constructor	Description
`CollectNodesVisitor(java.lang.Class<T> nodeClass)`	Construct a visitor
`CollectNodesVisitor(java.lang.Class<T> nodeClass, java.lang.Class<? extends Visitable> skipOverClass)`	Construct a visitor

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`java.util.List<T>`	`getList()`	Return the list of matching nodes.
`boolean`	`skipChildren(Visitable node)`	Don't visit children under the skipOverClass node, if it isn't null.
`boolean`	`stopTraversal()`	Method that is called to see if query tree traversal should be stopped before visiting all nodes.
`Visitable`	`visit(Visitable node)`	If we have found the target node, we are done.
`boolean`	`visitChildrenFirst(Visitable node)`	Method that is called to see if `visit()` should be called on the children of `node` before it is called on `node` itself.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - nodeList
```
private final java.util.List<T extends Visitable> nodeList
```
  - nodeClass
```
private final java.lang.Class<T extends Visitable> nodeClass
```
  - skipOverClass
```
private final java.lang.Class<? extends Visitable> skipOverClass
```
- Constructor Detail
  - CollectNodesVisitor
```
public CollectNodesVisitor(java.lang.Class<T> nodeClass)
```
    Construct a visitor
    
    Parameters:
    
    nodeClass - the class of the node that we are looking for.
  - CollectNodesVisitor
```
public CollectNodesVisitor(java.lang.Class<T> nodeClass,
                           java.lang.Class<? extends Visitable> skipOverClass)
```
    Construct a visitor
    
    Parameters:
    
    nodeClass - the class of the node that we are looking for.
    
    skipOverClass - do not go below this node when searching for nodeClass.
- Method Detail
  - visitChildrenFirst
```
public boolean visitChildrenFirst(Visitable node)
```
    Description copied from interface: Visitor
    
    Method that is called to see if visit() should be called on the children of node before it is called on node itself. If this method always returns true, the visitor will walk the tree bottom-up. If it always returns false, the tree is visited top-down.
    
    Specified by:
    
    visitChildrenFirst in interface Visitor
    
    Parameters:
    
    node - the top node of a sub-tree about to be visited
    
    Returns:
    
    true if node's children should be visited before node, false otherwise
  - stopTraversal
```
public boolean stopTraversal()
```
    Description copied from interface: Visitor
    
    Method that is called to see if query tree traversal should be stopped before visiting all nodes. Useful for short circuiting traversal if we already know we are done.
    
    Specified by:
    
    stopTraversal in interface Visitor
    
    Returns:
    
    true/false
  - visit
```
public Visitable visit(Visitable node)
```
    If we have found the target node, we are done.
    
    Specified by:
    
    visit in interface Visitor
    
    Parameters:
    
    node - the node to process
    
    Returns:
    
    me
  - skipChildren
```
public boolean skipChildren(Visitable node)
```
    Don't visit children under the skipOverClass node, if it isn't null.
    
    Specified by:
    
    skipChildren in interface Visitor
    
    Parameters:
    
    node - the node to process
    
    Returns:
    
    true/false
  - getList
```
public java.util.List<T> getList()
```
    Return the list of matching nodes. The returned list may be empty, if there are no matching nodes. It is never null.

Class CollectNodesVisitor<T extends Visitable>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

nodeList

nodeClass

skipOverClass

Constructor Detail

CollectNodesVisitor

CollectNodesVisitor

Method Detail

visitChildrenFirst

stopTraversal

visit

skipChildren

getList