public interface Node
Node represents a node in a graph.
A tree is a graph, so it may represent the root of a tree, a node corresponding to a proper subtree of the same tree, or simply a leaf node therein.
In this API, you can traverse a Node in at least two different ways. The first using an implementation of the interface NodeVisitor, which uses a design pattern called Visitor. The second using an implementation of the interface
NodeHierarchicalVisitor, which uses a design pattern called Hierarchical Visitor.
| Modifier and Type | Method and Description |
|---|---|
default boolean |
accept(NodeHierarchicalVisitor nodeHierarchicalVisitor)
Accepts a
NodeHierarchicalVisitor. |
default void |
accept(NodeVisitor nodeVisitor)
Accepts a
NodeVisitor. |
default boolean accept(NodeHierarchicalVisitor nodeHierarchicalVisitor)
NodeHierarchicalVisitor.
Returns the result of nodeHierarchicalVisitor.visitLeave(this).
If nodeHierarchicalVisitor is null, a NullPointerException may be thrown. But no guarantees can be made for all implementations.
If a RuntimeException is thrown by the current NodeHierarchicalVisitor, a NodeTraversalException may be thrown with the RuntimeException wrapped. But no guarantees can be made for all implementations.
To implement this method, consider the following example:
if(nodeHierarchicalVisitor.visitEnter(this)) {
for(Node childNode : childNodes) {
if(!childNode.accept(nodeHierarchicalVisitor)) {
break;
}
}
}
return nodeHierarchicalVisitor.visitLeave(this);
The default implementation will:
NullPointerException if nodeHierarchicalVisitor is null.NodeTraversalException if nodeHierarchicalVisitor throws a RuntimeException.Nodes, because it does not have any.nodeHierarchicalVisitor - the NodeHierarchicalVisitor to acceptnodeHierarchicalVisitor.visitLeave(this)NodeTraversalException - thrown if, and only if, a RuntimeException is thrown by the current NodeHierarchicalVisitorjava.lang.NullPointerException - thrown if, and only if, nodeHierarchicalVisitor is nulldefault void accept(NodeVisitor nodeVisitor)
NodeVisitor.
If nodeVisitor is null, a NullPointerException may be thrown. But no guarantees can be made for all implementations.
If a RuntimeException is thrown by the current NodeVisitor, a NodeTraversalException may be thrown with the RuntimeException wrapped. But no guarantees can be made for all implementations.
To implement this method, consider the following example:
nodeVisitor.accept(this);
The default implementation will:
NullPointerException if nodeVisitor is null.NodeTraversalException if nodeVisitor throws a RuntimeException.nodeVisitor - the NodeVisitor to acceptNodeTraversalException - thrown if, and only if, a RuntimeException is thrown by the current NodeVisitorjava.lang.NullPointerException - thrown if, and only if, nodeVisitor is null