com.allanbank.mongodb.bson.element

Class StringElement

java.lang.Object

com.allanbank.mongodb.bson.element.AbstractElement

com.allanbank.mongodb.bson.element.StringElement

All Implemented Interfaces:

Element, ElementAssignable, Serializable, Comparable<Element>

public class StringElement
extends AbstractElement

A wrapper for a BSON string.

See Also:

Serialized Form

API Notice:

This class is part of the driver's API. Public and protected members will be deprecated for at least 1 non-bugfix release (version numbers are <major>.<minor>.<bugfix>) before being removed or modified.

Copyright ©:

2011-2013, Allanbank Consulting, Inc., All Rights Reserved

Field Summary

Fields

Modifier and Type	Field and Description
static ElementType	TYPE The BSON type for a string.

Fields inherited from class com.allanbank.mongodb.bson.element.AbstractElement

ELEMENT_TYPE

Constructor Summary

Constructors

Constructor and Description
StringElement(String name, String value) Constructs a new StringElement.
StringElement(String name, String value, long size) Constructs a new StringElement.

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(Visitor visitor) Accepts the visitor and calls the Visitor.visitString(java.lang.String, java.lang.String) method.
int	compareTo(Element otherElement)
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.
ElementType	getType() Returns the type for the BSON type.
String	getValue() Returns the BSON string value.
String	getValueAsObject() Returns the value for BSON element as a Java Object type.
String	getValueAsString() Returns the value for BSON element as a Java String.
int	hashCode() Computes a reasonable hash code.
StringElement	withName(String name) Creates a new element with the same type and value as this element but with the specified name.

Methods inherited from class com.allanbank.mongodb.bson.element.AbstractElement

asElement, find, find, findFirst, findFirst, getName, nullSafeEquals, size, toString

Methods inherited from class java.lang.Object

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

Field Detail

TYPE

public static final ElementType TYPE

The BSON type for a string.

Constructor Detail

StringElement

public StringElement(String name,
             String value)

Constructs a new StringElement.

Parameters:

name - The name for the BSON string.

value - The BSON string value.

Throws:

IllegalArgumentException - If the name or value is null.

StringElement

public StringElement(String name,
             String value,
             long size)

Constructs a new StringElement.

Parameters:

name - The name for the BSON string.

value - The BSON string value.

size - The size of the element when encoded in bytes. If not known then use the StringElement(String, String) constructor instead.

Throws:

IllegalArgumentException - If the name or value is null.

Method Detail

accept

public void accept(Visitor visitor)

Accepts the visitor and calls the Visitor.visitString(java.lang.String, java.lang.String) method.

Parameters:

visitor - The visitor for the element.

See Also:

Element.accept(Visitor)

compareTo

public int compareTo(Element otherElement)

Overridden to compare the elements based on the tuple (name, type, value).

Overridden to compare the elements based on the tuple (name, type). Derived classes are responsible for the value portion of the full comparison.

Overridden to compare the string values if the base class comparison is equals.

Note that for MongoDB SymbolElement and StringElement will return equal based on the type. Care is taken here to make sure that the values return the same value regardless of comparison order.

Note: Comparison of strings in MongoDB does not use a collator. This class emulates the MongoDB behavior and orders the string elements based on the UTF-8 encoding of the strings.

Specified by:

compareTo in interface Element

Specified by:

compareTo in interface Comparable<Element>

Overrides:

compareTo in class AbstractElement

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 AbstractElement

Parameters:

object - The object to compare to.

See Also:

Object.equals(java.lang.Object)

getType

public ElementType getType()

Returns the type for the BSON type.

Returns:

The type for the BSON type.

getValue

public String getValue()

Returns the BSON string value.

Returns:

The BSON string value.

getValueAsObject

public String getValueAsObject()

Returns the value for BSON element as a Java Object type.

Automatic conversion from the Object-ified value to an element is provided via the DocumentBuilder.add(String, Object) method. Not all element types will be successfully converted to the same element duing a Element-->Object value-->Element conversion. This cases are noted in the appropriate sub-type's JavaDoc.

Sub-types will also overload this method with the appropriate type returned. e.g., The getValueAsObject() method signature returns a String.

Returns the String value.

Returns:

The value for BSON element as a Java Object type.

getValueAsString

public String getValueAsString()

Returns the value for BSON element as a Java String. Automatic conversion from the string value back to an Element is not provided.

Generally the string returned will be the expected value. As an example for a LongElement with the value 101 the returned string will be "101". In those cases where there is not canonical form for the value (e.g., a TimestampElement the returned string will match the value when converted to JSON by the JsonSerializationVisitor. For a TimestampElement that is a string of the form "ISODate('1970-01-01T00:00:00.000+0000')".

Uses the JsonSerializationVisitor to encode the value. In some cases it will be more efficient to override this method with a more straight forward conversion.

Returns the String value.

Specified by:

getValueAsString in interface Element

Overrides:

getValueAsString in class AbstractElement

Returns:

The value for BSON element as a String.

hashCode

public int hashCode()

Computes a reasonable hash code.

Overrides:

hashCode in class AbstractElement

Returns:

The hash code value.

withName

public StringElement withName(String name)

Creates a new element with the same type and value as this element but with the specified name. This is useful when creating a query across a set of collections where the filed name changes in the collections but the values must be identical.

Returns a new StringElement.

Parameters:

name - The new name for the element.

Returns:

The created element.