com.googlecode.objectify.impl

Class Node

java.lang.Object

com.googlecode.objectify.impl.Node

All Implemented Interfaces:

Iterable<Node>

public class Node
extends Object
implements Iterable<Node>

A tree repesentation of a datastore Entity object.

A node can have a map, a list, or a property value. However, these are not exclusive; because of the entity storage structure a node can have a map and a property value at the same place. Lists, however, stand alone.

Here is an example of a set of entity properties:

• field1.field2 = "foo"
• field1.field2.field3 = "bar"

This produces a tree that looks like:

root {
        field1: {
                field2: "foo" + {
                        field3: "bar"
                }
        }
}

Note that collection values are stored in their own property value nodes. For example:

• field1 = [ "foo", "bar" ]

Becomes this (note that each value in the collection is a node):

root {
        field1: [
                { "foo" },
                { "bar" }
        }
}

This is roughly similar to Jackson's JsonNode. One major difference is that there is not a class hierarchy of node types; this is because nodes can actually switch types during tree reprocessing.

Author:

Jeff Schnitzer

Constructor Summary

Constructors

Constructor and Description
Node(Path path)

Method Summary

Methods

Modifier and Type	Method and Description
Node	addToList() Creates a new node at same path, adds it to the list, and returns it
void	addToList(Node node) Adds a node to the list
void	addToMap(Node node) Adds a node to the map, keyed by its path segment
boolean	containsKey(String key) Checks to see of the map contains the key
Node	get(int index) Gets the node at the index of the list, assuming this is a list node
Node	get(String key) Gets key on a map node
Path	getPath() Gets the path to this node
Object	getPropertyValue()
boolean	hasList()
boolean	hasMap()
boolean	hasPropertyValue()
boolean	isEmpty() Test for empty of any node type
boolean	isPropertyIndexed()
Iterator<Node>	iterator() Iterate over the values in either the map or list, whichever is appropriate
static Node	of(Object value) Create a simple unindexed property value node with a root (basically meaningless) path
Node	path(int index) Gets the node at the index of the list, making sure that a node exists there.
Node	path(String key) Gets the node with the specified key in the map, making sure that a node exists there.
void	put(String key, Node value) Puts a value on a map node
Node	remove(String key) Removes from map node
void	setList(List<Node> newNodes) Changes any kind of node into a list node with the new contents
void	setPropertyIndexed(boolean value)
void	setPropertyValue(Object value)
void	setPropertyValue(Object value, boolean index)
int	size()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Node

public Node(Path path)

Method Detail

hasPropertyValue

public boolean hasPropertyValue()

getPropertyValue

public Object getPropertyValue()

setPropertyValue

public void setPropertyValue(Object value)

setPropertyValue

public void setPropertyValue(Object value,
                    boolean index)

isPropertyIndexed

public boolean isPropertyIndexed()

setPropertyIndexed

public void setPropertyIndexed(boolean value)

getPath

public Path getPath()

Gets the path to this node

hasList

public boolean hasList()

Returns:

true if this node has a list with contents

hasMap

public boolean hasMap()

Returns:

true if this node has a map with contents

size

public int size()

Returns:

the size of the list or map, whichever is appropriate

isEmpty

public boolean isEmpty()

Test for empty of any node type

setList

public void setList(List<Node> newNodes)

Changes any kind of node into a list node with the new contents

iterator

public Iterator<Node> iterator()

Iterate over the values in either the map or list, whichever is appropriate

Specified by:

iterator in interface Iterable<Node>

addToList

public Node addToList()

Creates a new node at same path, adds it to the list, and returns it

addToList

public void addToList(Node node)

Adds a node to the list

addToMap

public void addToMap(Node node)

Adds a node to the map, keyed by its path segment

path

public Node path(int index)

Gets the node at the index of the list, making sure that a node exists there. Assumes that the indexes are always fed in order.

path

public Node path(String key)

Gets the node with the specified key in the map, making sure that a node exists there.

get

public Node get(int index)

Gets the node at the index of the list, assuming this is a list node

Returns:

null if nothing at that index

get

public Node get(String key)

Gets key on a map node

put

public void put(String key,
       Node value)

Puts a value on a map node

containsKey

public boolean containsKey(String key)

Checks to see of the map contains the key

remove

public Node remove(String key)

Removes from map node

toString

public String toString()

Overrides:

toString in class Object

of

public static Node of(Object value)

Create a simple unindexed property value node with a root (basically meaningless) path