com.tinkerpop.blueprints.util

Class ElementHelper

java.lang.Object

com.tinkerpop.blueprints.util.ElementHelper

public class ElementHelper
extends Object

Author:

Marko A. Rodriguez (http://markorodriguez.com)

Constructor Summary

Constructors

Constructor and Description
ElementHelper()

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	areEqual(Element a, Object b) A standard method for determining if two elements are equal.
static void	copyProperties(Element from, Element to) Copy the properties (key and value) from one element to another.
static Map<String,Object>	getProperties(Element element) Get a clone of the properties of the provided element.
static boolean	haveEqualIds(Element a, Element b) Simply tests if the element ids are equal().
static boolean	haveEqualProperties(Element a, Element b) Determines whether two elements have the same properties.
static void	removeProperties(Iterable<Element> elements) Clear all the properties from an iterable of elements.
static void	removeProperty(String key, Iterable<Element> elements) Remove a property from all elements in the provided iterable.
static void	renameProperty(String oldKey, String newKey, Iterable<Element> elements) Renames a property by removing the old key and adding the stored value to the new key.
static void	setProperties(Element element, Map<String,Object> properties) Set the properties of the provided element using the provided map.
static void	setProperties(Element element, Object... keysValues) Set the properties of the provided element using the provided key value pairs.
static void	typecastProperty(String key, Class classCast, Iterable<Element> elements) Typecasts a property value.
static void	validateProperty(Element element, String key, Object value) Determines whether the property key/value for the specified element can be legally set.

Methods inherited from class java.lang.Object

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

Constructor Detail

ElementHelper

public ElementHelper()

Method Detail

validateProperty

public static final void validateProperty(Element element,
                    String key,
                    Object value)
                                   throws IllegalArgumentException

Determines whether the property key/value for the specified element can be legally set. This is typically used as a pre-condition check prior to setting a property.

Parameters:

element - the element for the property to be set

key - the key of the property

value - the value of the property

Throws:

IllegalArgumentException - whether the triple is legal and if not, a clear reason message is provided

copyProperties

public static void copyProperties(Element from,
                  Element to)

Copy the properties (key and value) from one element to another. The properties are preserved on the from element. ElementPropertiesRule that share the same key on the to element are overwritten.

Parameters:

from - the element to copy properties from

to - the element to copy properties to

removeProperties

public static void removeProperties(Iterable<Element> elements)

Clear all the properties from an iterable of elements.

Parameters:

elements - the elements to remove properties from

removeProperty

public static void removeProperty(String key,
                  Iterable<Element> elements)

Remove a property from all elements in the provided iterable.

Parameters:

key - the property to remove by key

elements - the elements to remove the property from

renameProperty

public static void renameProperty(String oldKey,
                  String newKey,
                  Iterable<Element> elements)

Renames a property by removing the old key and adding the stored value to the new key. If property does not exist, nothing occurs.

Parameters:

oldKey - the key to rename

newKey - the key to rename to

elements - the elements to rename

typecastProperty

public static void typecastProperty(String key,
                    Class classCast,
                    Iterable<Element> elements)

Typecasts a property value. This only works for casting to a class that has a constructor of the for new X(String). If no such constructor exists, a RuntimeException is thrown and the original element property is left unchanged.

Parameters:

key - the key for the property value to typecast

classCast - the class to typecast to

elements - the elements to have their property typecasted

haveEqualProperties

public static boolean haveEqualProperties(Element a,
                          Element b)

Determines whether two elements have the same properties. To be true, both must have the same property keys and respective values must be equals().

Parameters:

a - an element

b - an element

Returns:

whether the two elements have equal properties

getProperties

public static Map<String,Object> getProperties(Element element)

Get a clone of the properties of the provided element. In other words, a HashMap is created and filled with the key/values of the element's properties.

Parameters:

element - the element to get the properties of

Returns:

a clone of the properties of the element

setProperties

public static void setProperties(Element element,
                 Map<String,Object> properties)

Set the properties of the provided element using the provided map.

Parameters:

element - the element to set the properties of

properties - the properties to set as a Map

setProperties

public static void setProperties(Element element,
                 Object... keysValues)

Set the properties of the provided element using the provided key value pairs. The var args of Objects must be divisible by 2. All odd elements in the array must be a String key.

Parameters:

element - the element to set the properties of

keysValues - the key value pairs of the properties

areEqual

public static boolean areEqual(Element a,
               Object b)

A standard method for determining if two elements are equal. This method should be used by any Element.equals() implementation to ensure consistent behavior.

Parameters:

a - The first element

b - The second element (as an object)

Returns:

Whether the two elements are equal

haveEqualIds

public static boolean haveEqualIds(Element a,
                   Element b)

Simply tests if the element ids are equal().

Parameters:

a - the first element

b - the second element

Returns:

Whether the two elements have equal ids