helma.objectmodel.db
Class Node

java.lang.Object
  helma.objectmodel.db.Node

All Implemented Interfaces:

IPathElement, INode, INodeState, java.io.Serializable

public final class Node
extends java.lang.Object
implements INode, java.io.Serializable

An implementation of INode that can be stored in the internal database or an external relational database.

See Also:

Serialized Form

Field Summary

protected boolean	anonymous
protected long	created
protected long	lastmodified
protected NodeHandle	parentHandle
protected short	version

Fields inherited from interface helma.objectmodel.INodeState

CLEAN, DELETED, INVALID, MODIFIED, NEW, TRANSIENT, VIRTUAL

Constructor Summary

protected	Node() Creates an empty, uninitialized Node.
protected	Node(long timestamp) Creates an empty, uninitialized Node with the given create and modify time.
	Node(Node home, java.lang.String propname, WrappedNodeManager nmgr, java.lang.String prototype) Constructor used for virtual nodes.
	Node(java.lang.String name, java.lang.String id, java.lang.String prototype, WrappedNodeManager nmgr) Creates a new Node with the given name.
	Node(java.lang.String name, java.lang.String id, java.lang.String prototype, WrappedNodeManager nmgr, long created, long lastmodified) Constructor used to create a Node with a given name from a embedded database.
	Node(java.lang.String name, java.lang.String prototype, WrappedNodeManager nmgr) Creates a new Node with the given name.

Method Summary

INode	addNode(INode elem) INode-related
INode	addNode(INode elem, int where) Add a node to this Node's subnodes, making the added node persistent if it hasn't been before and this Node is already persistent.
void	clearCacheNode() Reset the cache node for this node.
int	contains(INode n) Check if the given node is contained in this node's child list.
long	created()
INode	createNode()
INode	createNode(int where)
INode	createNode(java.lang.String nm)
INode	createNode(java.lang.String nm, int where)
SubnodeList	createSubnodeList() Retrieve an empty subnodelist.
protected void	deepRemoveNode() Delete the node from the db.
void	dump()
IProperty	get(java.lang.String propname)
boolean	getBoolean(java.lang.String propname)
Node	getCachedParent() Get parent, using cached info if it exists.
INode	getCacheNode() Get the cache node for this node.
IPathElement	getChildElement(java.lang.String name) This implements the getChildElement() method of the IPathElement interface
java.util.Date	getDate(java.lang.String propname)
DbMapping	getDbMapping()
java.lang.String	getElementName() Get something to identify this node within a URL.
double	getFloat(java.lang.String propname)
java.lang.String	getFullName()
java.lang.String	getFullName(INode root)
protected Node	getGroupbySubnode(java.lang.String sid, boolean create)
NodeHandle	getHandle()
java.lang.String	getID() Get the ID of this Node.
long	getInteger(java.lang.String propname)
java.lang.Object	getJavaObject(java.lang.String propname)
Key	getKey()
java.lang.String	getName() Return this node' name, which may or may not have some meaning
INode	getNode(java.lang.String propname)
Node	getNonVirtualParent() This method walks down node path to the first non-virtual node and return it.
INode	getParent() Get parent, retrieving it if necessary.
IPathElement	getParentElement() This implements the getParentElement() method of the IPathElement interface
java.lang.String	getParentInfo()
protected Property	getProperty(java.lang.String propname)
java.util.Hashtable	getPropMap()
java.lang.String	getPrototype() Get the name of the prototype to be used for this object.
int	getState() Gets this node's stateas defined in the INode interface
java.lang.String	getString(java.lang.String propname)
INode	getSubnode(java.lang.String subid)
INode	getSubnodeAt(int index)
SubnodeList	getSubnodeList() Return this Node's subnode list
java.lang.String	getSubnodeRelation()
java.util.Enumeration	getSubnodes()
int	hashCode() We overwrite hashCode to make it dependant from the prototype.
void	init(DbMapping dbm, java.lang.String id, java.lang.String name, java.lang.String prototype, java.util.Hashtable propMap, WrappedNodeManager nmgr) Initializer used for nodes being instanced from an embedded or relational database.
void	invalidate() Mark node as invalid so it is re-fetched from the database
void	invalidateNode(java.lang.String key) Check for a child mapping and evict the object specified by key from the cache
boolean	isAnonymous() Returns true if this node is accessed by id from its aprent, false if it is accessed by name
boolean	isNullNode() Instances of this class may be used to mark an entry in the object cache as null.
boolean	isParentOf(Node n) Check if the given node is contained in this node's child list.
boolean	isRelational() Tell whether this node is stored inside a relational db.
long	lastModified()
void	loadNodes() Make sure the subnode index is loaded for subnodes stored in a relational data source.
void	markSubnodesChanged() Called by the transactor on registered parent nodes to mark the child index as changed
int	numberOfNodes() Count the subnodes of this node.
void	persist() Public method to make a node persistent.
void	prefetchChildren(int startIndex, int length)
void	prefetchChildren(Key[] keys)
java.util.Enumeration	properties() Get all properties of this node.
protected void	releaseNode(Node node) "Locally" remove a subnode from the subnodes table.
boolean	remove()
void	removeNode(INode node)
protected void	set(java.lang.String propname, java.lang.Object value, int type) Directly set a property on this node
void	setBoolean(java.lang.String propname, boolean value)
void	setDate(java.lang.String propname, java.util.Date value)
void	setDbMapping(DbMapping dbmap)
void	setFloat(java.lang.String propname, double value)
void	setInteger(java.lang.String propname, long value)
void	setJavaObject(java.lang.String propname, java.lang.Object value)
void	setName(java.lang.String name)
void	setNode(java.lang.String propname, INode value)
void	setParent(Node parent) Set this node's parent node.
void	setParentHandle(NodeHandle parent) Set this node's parent node to the node referred to by the NodeHandle.
void	setPropMap(java.util.Hashtable propMap) used by Xml deserialization
void	setPrototype(java.lang.String proto)
void	setState(int s) Sets this node's state as defined in the INode interface
void	setString(java.lang.String propname, java.lang.String value)
void	setSubnodeRelation(java.lang.String rel)
void	setSubnodes(SubnodeList subnodes) used by Xml deserialization
void	setWrappedNodeManager(WrappedNodeManager nmgr)
java.lang.String	toString() Return a string representation for this node.
void	unset(java.lang.String propname) Remove a property.
int	updateSubnodes() This method get's called from the JavaScript environment (HopObject.updateSubnodes() or HopObject.collection.updateSubnodes())) The subnode-collection will be updated with a selectstatement getting all Nodes having a higher id than the highest id currently contained within this Node's subnoderelation.

Methods inherited from class java.lang.Object

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

Field Detail

parentHandle

protected NodeHandle parentHandle

created

protected long created

lastmodified

protected long lastmodified

anonymous

protected boolean anonymous

version

protected short version

Constructor Detail

Node

protected Node()

Creates an empty, uninitialized Node. The init() method must be called on the Node before it can do anything useful.

Node

protected Node(long timestamp)

Creates an empty, uninitialized Node with the given create and modify time. This is used for null-node references in the node cache.

Parameters:

timestamp -

Node

public Node(java.lang.String name,
            java.lang.String id,
            java.lang.String prototype,
            WrappedNodeManager nmgr)

Creates a new Node with the given name. Used by NodeManager for creating "root nodes" outside of a Transaction context, which is why we can immediately mark it as CLEAN. Also used by embedded database to re-create an existing Node.

Node

public Node(java.lang.String name,
            java.lang.String id,
            java.lang.String prototype,
            WrappedNodeManager nmgr,
            long created,
            long lastmodified)

Constructor used to create a Node with a given name from a embedded database.

Node

public Node(Node home,
            java.lang.String propname,
            WrappedNodeManager nmgr,
            java.lang.String prototype)

Constructor used for virtual nodes.

Node

public Node(java.lang.String name,
            java.lang.String prototype,
            WrappedNodeManager nmgr)

Creates a new Node with the given name. This is used for ordinary transient nodes.

Method Detail

init

public void init(DbMapping dbm,
                 java.lang.String id,
                 java.lang.String name,
                 java.lang.String prototype,
                 java.util.Hashtable propMap,
                 WrappedNodeManager nmgr)

Initializer used for nodes being instanced from an embedded or relational database.

setPropMap

public void setPropMap(java.util.Hashtable propMap)

used by Xml deserialization

setSubnodes

public void setSubnodes(SubnodeList subnodes)

used by Xml deserialization

markSubnodesChanged

public void markSubnodesChanged()

Called by the transactor on registered parent nodes to mark the child index as changed

getState

public int getState()

Gets this node's stateas defined in the INode interface

Specified by:

getState in interface INode

Returns:

this node's state

setState

public void setState(int s)

Sets this node's state as defined in the INode interface

Specified by:

setState in interface INode

Parameters:

s - this node's new state

invalidate

public void invalidate()

Mark node as invalid so it is re-fetched from the database

invalidateNode

public void invalidateNode(java.lang.String key)

Check for a child mapping and evict the object specified by key from the cache

getID

public java.lang.String getID()

Get the ID of this Node. This is the primary database key and used as part of the key for the internal node cache.

Specified by:

getID in interface INode

isAnonymous

public boolean isAnonymous()

Returns true if this node is accessed by id from its aprent, false if it is accessed by name

Specified by:

isAnonymous in interface INode

Returns:

...

getName

public java.lang.String getName()

Return this node' name, which may or may not have some meaning

Specified by:

getName in interface INode

Returns:

...

getElementName

public java.lang.String getElementName()

Get something to identify this node within a URL. This is the ID for anonymous nodes and a property value for named properties.

Specified by:

getElementName in interface IPathElement

getFullName

public java.lang.String getFullName()

Specified by:

getFullName in interface INode

Returns:

...

getFullName

public java.lang.String getFullName(INode root)

Specified by:

getFullName in interface INode

Parameters:

root - ...

Returns:

...

getPrototype

public java.lang.String getPrototype()

Description copied from interface: IPathElement

Get the name of the prototype to be used for this object. This will determine which scripts, actions and skins can be called on it within the Helma scripting and rendering framework.

Specified by:

getPrototype in interface IPathElement

Specified by:

getPrototype in interface INode

Returns:

...

setPrototype

public void setPrototype(java.lang.String proto)

Specified by:

setPrototype in interface INode

Parameters:

proto - ...

setDbMapping

public void setDbMapping(DbMapping dbmap)

Specified by:

setDbMapping in interface INode

Parameters:

dbmap - ...

getDbMapping

public DbMapping getDbMapping()

Specified by:

getDbMapping in interface INode

Returns:

...

setWrappedNodeManager

public void setWrappedNodeManager(WrappedNodeManager nmgr)

Parameters:

nmgr -

getKey

public Key getKey()

Returns:

...

getHandle

public NodeHandle getHandle()

Returns:

...

setSubnodeRelation

public void setSubnodeRelation(java.lang.String rel)

Specified by:

setSubnodeRelation in interface INode

Parameters:

rel - ...

getSubnodeRelation

public java.lang.String getSubnodeRelation()

Specified by:

getSubnodeRelation in interface INode

Returns:

...

setName

public void setName(java.lang.String name)

Specified by:

setName in interface INode

Parameters:

name - ...

setParent

public void setParent(Node parent)

Set this node's parent node.

setParentHandle

public void setParentHandle(NodeHandle parent)

Set this node's parent node to the node referred to by the NodeHandle.

getParent

public INode getParent()

Get parent, retrieving it if necessary.

Specified by:

getParent in interface INode

getCachedParent

public Node getCachedParent()

Get parent, using cached info if it exists.

addNode

public INode addNode(INode elem)

INode-related

Specified by:

addNode in interface INode

Parameters:

elem - ...

Returns:

...

addNode

public INode addNode(INode elem,
                     int where)

Add a node to this Node's subnodes, making the added node persistent if it hasn't been before and this Node is already persistent.

Specified by:

addNode in interface INode

Parameters:

elem - the node to add to this Nodes subnode-list

where - the index-position where this node has to be added

Returns:

the added node itselve

createNode

public INode createNode()

Returns:

...

createNode

public INode createNode(int where)

Parameters:

where - ...

Returns:

...

createNode

public INode createNode(java.lang.String nm)

Specified by:

createNode in interface INode

Parameters:

nm - ...

Returns:

...

createNode

public INode createNode(java.lang.String nm,
                        int where)

Specified by:

createNode in interface INode

Parameters:

nm - ...

where - ...

Returns:

...

getChildElement

public IPathElement getChildElement(java.lang.String name)

This implements the getChildElement() method of the IPathElement interface

Specified by:

getChildElement in interface IPathElement

getParentElement

public IPathElement getParentElement()

This implements the getParentElement() method of the IPathElement interface

Specified by:

getParentElement in interface IPathElement

getSubnode

public INode getSubnode(java.lang.String subid)

Specified by:

getSubnode in interface INode

Parameters:

subid - ...

Returns:

...

getSubnodeAt

public INode getSubnodeAt(int index)

Specified by:

getSubnodeAt in interface INode

Parameters:

index - ...

Returns:

...

getGroupbySubnode

protected Node getGroupbySubnode(java.lang.String sid,
                                 boolean create)

Parameters:

sid - ...

create - ...

Returns:

...

remove

public boolean remove()

Specified by:

remove in interface INode

Returns:

...

removeNode

public void removeNode(INode node)

Specified by:

removeNode in interface INode

Parameters:

node - ...

releaseNode

protected void releaseNode(Node node)

"Locally" remove a subnode from the subnodes table. The logical stuff necessary for keeping data consistent is done in removeNode(INode).

deepRemoveNode

protected void deepRemoveNode()

Delete the node from the db. This mainly tries to notify all nodes referring to this that it's going away. For nodes from the embedded db it also does a cascading delete, since it can tell which nodes are actual children and which are just linked in.

contains

public int contains(INode n)

Check if the given node is contained in this node's child list. If it is contained return its index in the list, otherwise return -1.

Specified by:

contains in interface INode

Parameters:

n - a node

Returns:

the node's index position in the child list, or -1

isParentOf

public boolean isParentOf(Node n)

Check if the given node is contained in this node's child list. This is similar to contains(INode) but does not load the child index for relational nodes.

Parameters:

n - a node

Returns:

true if the given node is contained in this node's child list

numberOfNodes

public int numberOfNodes()

Count the subnodes of this node. If they're stored in a relational data source, we may actually load their IDs in order to do this.

Specified by:

numberOfNodes in interface INode

Returns:

...

loadNodes

public void loadNodes()

Make sure the subnode index is loaded for subnodes stored in a relational data source. Depending on the subnode.loadmode specified in the type.properties, we'll load just the ID index or the actual nodes.

createSubnodeList

public SubnodeList createSubnodeList()

Retrieve an empty subnodelist. This empty List is an instance of the Class used for this Nodes subnode-list

Returns:

List an empty List of the type used by this Node

prefetchChildren

public void prefetchChildren(int startIndex,
                             int length)
                      throws java.lang.Exception

Parameters:

startIndex - ...

length - ...

Throws:

java.lang.Exception - ...

prefetchChildren

public void prefetchChildren(Key[] keys)
                      throws java.lang.Exception

Throws:

java.lang.Exception

getSubnodes

public java.util.Enumeration getSubnodes()

Specified by:

getSubnodes in interface INode

Returns:

...

getSubnodeList

public SubnodeList getSubnodeList()

Return this Node's subnode list

Returns:

the subnode list

properties

public java.util.Enumeration properties()

Get all properties of this node.

Specified by:

properties in interface INode

getPropMap

public java.util.Hashtable getPropMap()

Returns:

...

get

public IProperty get(java.lang.String propname)

Specified by:

get in interface INode

Parameters:

propname - ...

Returns:

...

getParentInfo

public java.lang.String getParentInfo()

Returns:

...

getProperty

protected Property getProperty(java.lang.String propname)

Parameters:

propname - ...

Returns:

...

getString

public java.lang.String getString(java.lang.String propname)

Specified by:

getString in interface INode

Parameters:

propname - ...

Returns:

...

getInteger

public long getInteger(java.lang.String propname)

Specified by:

getInteger in interface INode

Parameters:

propname - ...

Returns:

...

getFloat

public double getFloat(java.lang.String propname)

Specified by:

getFloat in interface INode

Parameters:

propname - ...

Returns:

...

getDate

public java.util.Date getDate(java.lang.String propname)

Specified by:

getDate in interface INode

Parameters:

propname - ...

Returns:

...

getBoolean

public boolean getBoolean(java.lang.String propname)

Specified by:

getBoolean in interface INode

Parameters:

propname - ...

Returns:

...

getNode

public INode getNode(java.lang.String propname)

Specified by:

getNode in interface INode

Parameters:

propname - ...

Returns:

...

getJavaObject

public java.lang.Object getJavaObject(java.lang.String propname)

Specified by:

getJavaObject in interface INode

Parameters:

propname - ...

Returns:

...

set

protected void set(java.lang.String propname,
                   java.lang.Object value,
                   int type)

Directly set a property on this node

Parameters:

propname - ...

value - ...

setString

public void setString(java.lang.String propname,
                      java.lang.String value)

Specified by:

setString in interface INode

Parameters:

propname - ...

value - ...

setInteger

public void setInteger(java.lang.String propname,
                       long value)

Specified by:

setInteger in interface INode

Parameters:

propname - ...

value - ...

setFloat

public void setFloat(java.lang.String propname,
                     double value)

Specified by:

setFloat in interface INode

Parameters:

propname - ...

value - ...

setBoolean

public void setBoolean(java.lang.String propname,
                       boolean value)

Specified by:

setBoolean in interface INode

Parameters:

propname - ...

value - ...

setDate

public void setDate(java.lang.String propname,
                    java.util.Date value)

Specified by:

setDate in interface INode

Parameters:

propname - ...

value - ...

setJavaObject

public void setJavaObject(java.lang.String propname,
                          java.lang.Object value)

Specified by:

setJavaObject in interface INode

Parameters:

propname - ...

value - ...

setNode

public void setNode(java.lang.String propname,
                    INode value)

Specified by:

setNode in interface INode

Parameters:

propname - ...

value - ...

unset

public void unset(java.lang.String propname)

Remove a property. Note that this works only for explicitly set properties, not for those specified via property relation.

Specified by:

unset in interface INode

Parameters:

propname - ...

lastModified

public long lastModified()

Specified by:

lastModified in interface INode

Returns:

...

created

public long created()

Specified by:

created in interface INode

Returns:

...

toString

public java.lang.String toString()

Return a string representation for this node. This tries to call the javascript implemented toString() if it is defined.

Overrides:

toString in class java.lang.Object

Returns:

a string representing this node.

isRelational

public boolean isRelational()

Tell whether this node is stored inside a relational db. This doesn't mean it actually is stored in a relational db, just that it would be, if the node was persistent

persist

public void persist()

Public method to make a node persistent.

getCacheNode

public INode getCacheNode()

Get the cache node for this node. This can be used to store transient cache data per node from Javascript.

Specified by:

getCacheNode in interface INode

Returns:

...

clearCacheNode

public void clearCacheNode()

Reset the cache node for this node.

Specified by:

clearCacheNode in interface INode

getNonVirtualParent

public Node getNonVirtualParent()

This method walks down node path to the first non-virtual node and return it. limit max depth to 5, since there shouldn't be more then 2 layers of virtual nodes.

isNullNode

public boolean isNullNode()

Instances of this class may be used to mark an entry in the object cache as null. This method tells the caller whether this is the case.

hashCode

public int hashCode()

We overwrite hashCode to make it dependant from the prototype. That way, when the prototype changes, the node will automatically get a new ESNode wrapper, since they're cached in a hashtable. You gotta love these hash code tricks ;-)

Overrides:

hashCode in class java.lang.Object

dump

public void dump()

updateSubnodes

public int updateSubnodes()

This method get's called from the JavaScript environment (HopObject.updateSubnodes() or HopObject.collection.updateSubnodes())) The subnode-collection will be updated with a selectstatement getting all Nodes having a higher id than the highest id currently contained within this Node's subnoderelation. If this subnodelist has a special order all nodes will be loaded honoring this order. Example: order by somefield1 asc, somefieled2 desc gives a where-clausel like the following: (somefiled1 > theHighestKnownValue value and somefield2 < theLowestKnownValue)

Returns:

the number of loaded nodes within this collection update