org.apache.commons.configuration

Class HierarchicalConfiguration.BuilderVisitor

java.lang.Object

org.apache.commons.configuration.HierarchicalConfiguration.NodeVisitor

org.apache.commons.configuration.HierarchicalConfiguration.BuilderVisitor

Enclosing class:

HierarchicalConfiguration

protected abstract static class HierarchicalConfiguration.BuilderVisitor
extends HierarchicalConfiguration.NodeVisitor

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 java.lang.Object	insert(HierarchicalConfiguration.Node newNode, HierarchicalConfiguration.Node parent, HierarchicalConfiguration.Node sibling1, HierarchicalConfiguration.Node sibling2) Inserts a new node into the structure constructed by this builder.
void	visitBeforeChildren(HierarchicalConfiguration.Node node, ConfigurationKey key) Visits the specified node before its children have been traversed.

Methods inherited from class org.apache.commons.configuration.HierarchicalConfiguration.NodeVisitor

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(HierarchicalConfiguration.Node node,
                                ConfigurationKey key)

Visits the specified node before its children have been traversed.

Overrides:

visitBeforeChildren in class HierarchicalConfiguration.NodeVisitor

Parameters:

node - the node to visit

key - the current key

insert

protected abstract java.lang.Object insert(HierarchicalConfiguration.Node newNode,
                                           HierarchicalConfiguration.Node parent,
                                           HierarchicalConfiguration.Node sibling1,
                                           HierarchicalConfiguration.Node sibling2)

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. The return value is interpreted as the new reference of the affected Node object; if it is not null , it is passed to the node's setReference() method.

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

Returns:

the reference object for the node to be inserted