Author: oheger
Date: Mon Nov 2 06:41:11 2009
New Revision: 831803
URL: http://svn.apache.org/viewvc?rev=831803&view=rev
Log:
Moved default implementation of visitor mechanism to NodeVisitorAdapter so that
it can be better reused.
Modified:
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/AbstractHierarchicalConfiguration.java
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/expr/NodeVisitorAdapter.java
Modified:
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/AbstractHierarchicalConfiguration.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/AbstractHierarchicalConfiguration.java?rev=831803&r1=831802&r2=831803&view=diff
==============================================================================
---
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/AbstractHierarchicalConfiguration.java
(original)
+++
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/AbstractHierarchicalConfiguration.java
Mon Nov 2 06:41:11 2009
@@ -712,17 +712,7 @@
*/
protected void visit(T node, NodeVisitor<T> visitor)
{
- if (!visitor.terminate())
- {
- visitor.visitBeforeChildren(node, getNodeHandler());
-
- for (Iterator<T> it =
getNodeHandler().getChildren(node).iterator(); it.hasNext() &&
!visitor.terminate();)
- {
- visit(it.next(), visitor);
- }
-
- visitor.visitAfterChildren(node, getNodeHandler());
- }
+ NodeVisitorAdapter.visit(visitor, node, getNodeHandler());
}
/**
Modified:
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/expr/NodeVisitorAdapter.java
URL:
http://svn.apache.org/viewvc/commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/expr/NodeVisitorAdapter.java?rev=831803&r1=831802&r2=831803&view=diff
==============================================================================
---
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/expr/NodeVisitorAdapter.java
(original)
+++
commons/proper/configuration/branches/configuration2_experimental/src/main/java/org/apache/commons/configuration2/expr/NodeVisitorAdapter.java
Mon Nov 2 06:41:11 2009
@@ -16,6 +16,8 @@
*/
package org.apache.commons.configuration2.expr;
+import java.util.Iterator;
+
/**
* <p>
* A simple adapter class that simplifies writing custom node visitor
@@ -23,11 +25,20 @@
* </p>
* <p>
* This class provides dummy implementations for the methods defined in the
- * <code>ConfigurationNodeVisitor</code> interface. Derived classes only need
- * to override the methods they really need.
+ * {...@link NodeVisitor} interface. Derived classes only need to override the
+ * methods they really need.
+ * </p>
+ * <p>
+ * In addition to the dummy implementations of the {...@link NodeVisitor}
methods,
+ * this class also provides a static method that implements the default
visiting
+ * mechanism: The {...@code visit()} method is passed a {...@code
NodeVisitor}, a
+ * node, and a corresponding {...@code NodeHandler}. It then traverses the
whole
+ * nodes structure and invokes the visitor for each encountered node.
* </p>
*
- * @author Oliver Heger
+ * @author <a
+ *
href="http://commons.apache.org/configuration/team-list.html";>Commons
+ * Configuration team</a>
* @version $Id$
* @param <T> the type of the involved nodes
*/
@@ -65,4 +76,34 @@
public void visitBeforeChildren(T node, NodeHandler<T> handler)
{
}
+
+ /**
+ * Traverses the nodes structure below the specified root node and calls
the
+ * visitor for each encountered node. If the {...@code terminate()} method
of
+ * the visitor returns <b>true</b>, the visit operation is aborted. This
+ * method provides a default implementation of the visitor mechanism.
+ *
+ * @param <N> the type of the nodes involved
+ * @param visitor the visitor
+ * @param node the root node of the hierarchy
+ * @param handler the node handler
+ * @throws NullPointerException if a required parameter is missing
+ */
+ public static <N> void visit(NodeVisitor<N> visitor, N node,
+ NodeHandler<N> handler)
+ {
+ if (!visitor.terminate())
+ {
+ visitor.visitBeforeChildren(node, handler);
+
+ for (Iterator<N> it = handler.getChildren(node).iterator(); it
+ .hasNext()
+ && !visitor.terminate();)
+ {
+ visit(visitor, it.next(), handler);
+ }
+
+ visitor.visitAfterChildren(node, handler);
+ }
+ }
}
