org.apache.commons.configuration2

Class BaseHierarchicalConfiguration.BuilderVisitor

java.lang.Object

org.apache.commons.configuration2.tree.ConfigurationNodeVisitorAdapter<ImmutableNode>

org.apache.commons.configuration2.BaseHierarchicalConfiguration.BuilderVisitor

All Implemented Interfaces:

ConfigurationNodeVisitor<ImmutableNode>

Enclosing class:

BaseHierarchicalConfiguration

protected abstract static class BaseHierarchicalConfiguration.BuilderVisitor
extends ConfigurationNodeVisitorAdapter<ImmutableNode>

A specialized visitor base class that can be used for storing the tree of configuration nodes. The basic idea is that each node can be associated with a reference object. This reference object has a concrete meaning in a derived class, e.g. an entry in a JNDI context or an XML element. When the configuration tree is set up, the load() method is responsible for setting the reference objects. When the configuration tree is later modified, new nodes do not have a defined reference object. This visitor class processes all nodes and finds the ones without a defined reference object. For those nodes the insert() method is called, which must be defined in concrete sub classes. This method can perform all steps to integrate the new node into the original structure.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BuilderVisitor()

Method Summary

Modifier and Type	Method and Description
protected abstract void	insert(ImmutableNode newNode, ImmutableNode parent, ImmutableNode sibling1, ImmutableNode sibling2, ReferenceNodeHandler refHandler) Inserts a new node into the structure constructed by this builder.
protected abstract void	update(ImmutableNode node, Object reference, ReferenceNodeHandler refHandler) Updates a node that already existed in the original hierarchy.
void	visitBeforeChildren(ImmutableNode node, NodeHandler<ImmutableNode> handler) Visits the specified node before the children of this node - if existing - are processed.

Methods inherited from class org.apache.commons.configuration2.tree.ConfigurationNodeVisitorAdapter

terminate, visitAfterChildren

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BuilderVisitor

protected BuilderVisitor()

Method Detail

visitBeforeChildren

public void visitBeforeChildren(ImmutableNode node,
                                NodeHandler<ImmutableNode> handler)

Description copied from class: ConfigurationNodeVisitorAdapter

Visits the specified node before the children of this node - if existing - are processed. Empty dummy implementation of this interface method.

Specified by:

visitBeforeChildren in interface ConfigurationNodeVisitor<ImmutableNode>

Overrides:

visitBeforeChildren in class ConfigurationNodeVisitorAdapter<ImmutableNode>

Parameters:

node - the node to be visited

handler - the NodeHandler

insert

protected abstract void insert(ImmutableNode newNode,
                               ImmutableNode parent,
                               ImmutableNode sibling1,
                               ImmutableNode sibling2,
                               ReferenceNodeHandler refHandler)

Inserts a new node into the structure constructed by this builder. This method is called for each node that has been added to the configuration tree after the configuration has been loaded from its source. These new nodes have to be inserted into the original structure. The passed in nodes define the position of the node to be inserted: its parent and the siblings between to insert.

Parameters:

newNode - the node to be inserted

parent - the parent node

sibling1 - the sibling after which the node is to be inserted; can be null if the new node is going to be the first child node

sibling2 - the sibling before which the node is to be inserted; can be null if the new node is going to be the last child node

refHandler - the ReferenceNodeHandler

update

protected abstract void update(ImmutableNode node,
                               Object reference,
                               ReferenceNodeHandler refHandler)

Updates a node that already existed in the original hierarchy. This method is called for each node that has an assigned reference object. A concrete implementation should update the reference according to the node's current value.

Parameters:

node - the current node to be processed

reference - the reference object for this node

refHandler - the ReferenceNodeHandler