public class OverrideCombiner extends NodeCombiner
A concrete combiner implementation that is able to construct an override combination.
An override combination means that nodes in the first node
structure take precedence over nodes in the second, or - in other words -
nodes of the second structure are only added to the resulting structure if
they do not occur in the first one. This is especially suitable for dealing
with the properties of configurations that are defined in an
override section of a configuration definition file (hence the
name).
This combiner will iterate over the second node hierarchy and find all nodes
that are not contained in the first hierarchy; these are added to the result.
If a node can be found in both structures, it is checked whether a
combination (in a recursive way) can be constructed for the two, which will
then be added. Per default, nodes are combined, which occur only once in both
structures. This test is implemented in the canCombine()
method.
As is true for the UnionCombiner, for this combiner
list nodes are important. The addListNode() can be called to
declare certain nodes as list nodes. This has the effect that these nodes
will never be combined.
listNodes| Constructor and Description |
|---|
OverrideCombiner() |
| Modifier and Type | Method and Description |
|---|---|
protected void |
addAttributes(ViewNode result,
ConfigurationNode node1,
ConfigurationNode node2)
Handles the attributes during a combination process.
|
protected ConfigurationNode |
canCombine(ConfigurationNode node1,
ConfigurationNode node2,
ConfigurationNode child)
Tests if a child node of the second node can be combined with the given
child node of the first node.
|
ConfigurationNode |
combine(ConfigurationNode node1,
ConfigurationNode node2)
Constructs an override combination for the passed in node structures.
|
addListNode, createViewNode, getListNodes, isListNodepublic ConfigurationNode combine(ConfigurationNode node1, ConfigurationNode node2)
combine in class NodeCombinernode1 - the first nodenode2 - the second nodeprotected void addAttributes(ViewNode result, ConfigurationNode node1, ConfigurationNode node2)
result - the resulting nodenode1 - the first nodenode2 - the second nodeprotected ConfigurationNode canCombine(ConfigurationNode node1, ConfigurationNode node2, ConfigurationNode child)
node1 - the first nodenode2 - the second nodechild - the child node (of the first node)Copyright © 2001–2013 The Apache Software Foundation. All rights reserved.