com.allanbank.mongodb.bson.impl

Class EmptyDocument

java.lang.Object

com.allanbank.mongodb.bson.impl.EmptyDocument

All Implemented Interfaces:

Document, DocumentAssignable, Serializable, Iterable<Element>

public class EmptyDocument
extends Object
implements Document

An immutable empty document.

See Also:

Serialized Form

API Warning:

This class is NOT part of the drivers API. This class may be mutated in incompatible ways between any two releases of the driver.

Copyright ©:

2011, Allanbank Consulting, Inc., All Rights Reserved

Field Summary

Fields

Modifier and Type	Field and Description
static List<Element>	EMPTY_ELEMENTS The empty list of elements.
static EmptyDocument	INSTANCE An instance of the Empty Document.

Constructor Summary

Constructors

Constructor and Description
EmptyDocument() Constructs a new EmptyDocument.

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(Visitor visitor) Accepts the visitor and calls the Visitor.visitDocument(java.lang.String, java.util.List<com.allanbank.mongodb.bson.Element>) method.
Document	asDocument() Converts the object into a document.
boolean	contains(String name) Returns false since this document contains no Elements.
boolean	equals(Object object) Determines if the passed object is of this same type as this object and if so that its fields are equal.
<E extends Element> List<E>	find(Class<E> clazz, String... nameRegexs) Returns the elements matching the path of regular expressions.
List<Element>	find(String... nameRegexs) Returns the elements matching the path of regular expressions.
<E extends Element> E	findFirst(Class<E> clazz, String... nameRegexs) Returns the first element matching the path of regular expressions.
Element	findFirst(String... nameRegexs) Returns the first element matching the path of regular expressions.
<E extends Element> E	get(Class<E> clazz, String name) Returns an empty list of elements.
Element	get(String name) Returns an empty list of elements.
List<Element>	getElements() Returns an empty list of elements.
int	hashCode() Computes a reasonable hash code.
Iterator<Element>	iterator() Returns an iterator over an empty list of elements.
<E extends Element> List<E>	queryPath(Class<E> clazz, String... nameRegexs) Deprecated. Use the find(Class,String...) method instead. Will be removed after the 1.1.0 release.
List<Element>	queryPath(String... nameRegexs) Deprecated. Use the find(Class,String...) method instead. Will be removed after the 1.1.0 release.
String	toString() String form of the object.

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY_ELEMENTS

public static final List<Element> EMPTY_ELEMENTS

The empty list of elements.

INSTANCE

public static final EmptyDocument INSTANCE

An instance of the Empty Document.

Constructor Detail

EmptyDocument

public EmptyDocument()

Constructs a new EmptyDocument.

Method Detail

accept

public void accept(Visitor visitor)

Accepts the visitor and calls the Visitor.visitDocument(java.lang.String, java.util.List<com.allanbank.mongodb.bson.Element>) method.

Specified by:

accept in interface Document

Parameters:

visitor - THe visitor for the document.

See Also:

Element.accept(Visitor)

asDocument

public Document asDocument()

Converts the object into a document.

Returns this document.

Specified by:

asDocument in interface DocumentAssignable

Returns:

The object as a Document.

contains

public boolean contains(String name)

Returns false since this document contains no Elements.

Specified by:

contains in interface Document

Parameters:

name - The name of the element to locate.

Returns:

True if the document contains an element with the given name, false otherwise.

See Also:

Document.contains(String)

equals

public boolean equals(Object object)

Determines if the passed object is of this same type as this object and if so that its fields are equal.

Overrides:

equals in class Object

Parameters:

object - The object to compare to.

See Also:

Object.equals(java.lang.Object)

find

public <E extends Element> List<E> find(Class<E> clazz,
                               String... nameRegexs)

Returns the elements matching the path of regular expressions.

Returns an empty list of elements.

Specified by:

find in interface Document

Type Parameters:

E - The type of element to match.

Parameters:

clazz - The class of elements to match.

nameRegexs - The path of regular expressions.

Returns:

The elements matching the path of regular expressions. May be an empty list but will never be null.

See Also:

Document.queryPath(java.lang.Class<E>, java.lang.String...)

find

public List<Element> find(String... nameRegexs)

Returns the elements matching the path of regular expressions.

Returns an empty list of elements.

Specified by:

find in interface Document

Parameters:

nameRegexs - The path of regular expressions.

Returns:

The elements matching the path of regular expressions. May be an empty list but will never be null.

See Also:

Document.queryPath(java.lang.Class<E>, java.lang.String...)

findFirst

public <E extends Element> E findFirst(Class<E> clazz,
                              String... nameRegexs)

Returns the first element matching the path of regular expressions.

Note: It is much faster to use the Document.get(Class,String) method on a document than to use the Document.findFirst(String...) with a single nameRegexs.

Return null.

Specified by:

findFirst in interface Document

Type Parameters:

E - The type of element to match.

Parameters:

clazz - The class of element to match.

nameRegexs - The path of regular expressions.

Returns:

The first element matching the path of regular expressions.

See Also:

Document.queryPath(java.lang.Class<E>, java.lang.String...)

findFirst

public Element findFirst(String... nameRegexs)

Returns the first element matching the path of regular expressions.

Note: It is much faster to use the Document.get(String) method on a document than to use the Document.findFirst(String...) with a single nameRegexs.

Returns null.

Specified by:

findFirst in interface Document

Parameters:

nameRegexs - The path of regular expressions.

Returns:

The first element matching the path of regular expressions.

See Also:

Document.queryPath(java.lang.Class<E>, java.lang.String...)

get

public <E extends Element> E get(Class<E> clazz,
                        String name)

Returns an empty list of elements.

Specified by:

get in interface Document

Type Parameters:

E - The type of element to get.

Parameters:

clazz - The class of element to get.

name - The name of the element to locate.

Returns:

The sub-element in the document with the given name or null if element exists with the given name.

See Also:

Document.get(String)

get

public Element get(String name)

Returns an empty list of elements.

Specified by:

get in interface Document

Parameters:

name - The name of the element to locate.

Returns:

The sub-element in the document with the given name or null if element exists with the given name.

See Also:

Document.get(String)

getElements

public List<Element> getElements()

Returns an empty list of elements.

Specified by:

getElements in interface Document

Returns:

The elements in the document.

hashCode

public int hashCode()

Computes a reasonable hash code.

Overrides:

hashCode in class Object

Returns:

The hash code value.

iterator

public Iterator<Element> iterator()

Returns an iterator over an empty list of elements.

Specified by:

iterator in interface Iterable<Element>

See Also:

Iterable.iterator()

queryPath

@Deprecated
public <E extends Element> List<E> queryPath(Class<E> clazz,
                                               String... nameRegexs)

Deprecated. Use the find(Class,String...) method instead. Will be removed after the 1.1.0 release.

Returns the elements matching the path of regular expressions.

Returns an empty list of elements.

Specified by:

queryPath in interface Document

Type Parameters:

E - The type of element to match.

Parameters:

clazz - The class of elements to match.

nameRegexs - The path of regular expressions.

Returns:

The elements matching the path of regular expressions.

See Also:

Document.queryPath(java.lang.Class<E>, java.lang.String...)

queryPath

@Deprecated
public List<Element> queryPath(String... nameRegexs)

Deprecated. Use the find(Class,String...) method instead. Will be removed after the 1.1.0 release.

Returns the elements matching the path of regular expressions.

Returns an empty list of elements.

Specified by:

queryPath in interface Document

Parameters:

nameRegexs - The path of regular expressions.

Returns:

The elements matching the path of regular expressions.

See Also:

Document.queryPath(java.lang.Class<E>, java.lang.String...)

toString

public String toString()

String form of the object.

Overrides:

toString in class Object

Returns:

A human readable form of the object.

See Also:

Object.toString()