Map

This extension provides capability to generate and manipulate map (key-value) data objects.

Features

• collect (Aggregate Function)

  Collect multiple key-value pairs to construct a map. Only distinct keys are collected, if a duplicate key arrives, it overrides the old value

• merge (Aggregate Function)

  Collect multiple maps to merge as a single map. Only distinct keys are collected, if a duplicate key arrives, it overrides the old value.

• clear (Function)

  Function returns the cleared map.

• clone (Function)

  Function returns the cloned map.

• combineByKey (Function)

  Function returns the map after combining all the maps given as parameters, such that the keys, of all the maps will be matched with an Array list of values from each map respectively.

• containsKey (Function)

  Function checks if the map contains the key.

• containsValue (Function)

  Function checks if the map contains the value.

• create (Function)

  Function creates a map pairing the keys and their corresponding values.

• createFromJSON (Function)

  Function returns the map created by pairing the keys with their corresponding values given in the JSON string.

• createFromXML (Function)

  Function returns the map created by pairing the keys with their corresponding values,given as an XML string.

• get (Function)

  Function returns the value corresponding to the given key from the map.

• isEmpty (Function)

  Function checks if the map is empty.

• isMap (Function)

  Function checks if the object is type of a map.

• keys (Function)

  Function to return the keys of the map as a list.

• put (Function)

  Function returns the updated map after adding the given key-value pair. If the key already exist in the map the key is updated with the new value.

• putAll (Function)

  Function returns the updated map after adding all the key-value pairs from another map. If there are duplicate keys, the key will be assigned new values from the map that\'s being copied.

• putIfAbsent (Function)

  Function returns the updated map after adding the given key-value pair if key is absent.

• remove (Function)

  Function returns the updated map after removing the element with the specified key.

• replace (Function)

  Function returns the updated map after replacing the given key-value pair only if key is present.

• replaceAll (Function)

  Function returns the updated map after replacing all the key-value pairs from another map, if keys are present.

• size (Function)

  Function to return the size of the map.

• toJSON (Function)

  Function converts a map into a JSON object and returns the JSON as a string.

• toXML (Function)

  Function returns the map as an XML string.

• values (Function)

  Function to return the values of the map.

• tokenize (StreamProcessor)

  okenize the map and return each key, value as new attributes in events

collect

Collect multiple key-value pairs to construct a map. Only distinct keys are collected, if a duplicate key arrives, it overrides the old value

Syntax

<OBJECT> map:collect(<INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key, <OBJECT|INT|LONG|FLOAT|DOUBLE|BOOL|STRING> value)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
key	Key of the map entry		INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes
value	Value of the map entry		OBJECT INT LONG FLOAT DOUBLE BOOL STRING	No	Yes

EXAMPLE 1

insert into OutputStream
select map:collect(symbol, price) as stockDetails
from StockStream#window.lengthBatch(10);

For the window expiry of 10 events, the collect() function will collect attributes of key and value to a single map and return as stockDetails.

merge

Collect multiple maps to merge as a single map. Only distinct keys are collected, if a duplicate key arrives, it overrides the old value.

Syntax

<OBJECT> map:merge(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	Maps to be collected		OBJECT	No	Yes

EXAMPLE 1

insert into OutputStream
select map:merge(map) as stockDetails
from StockStream#window.lengthBatch(2);

For the window expiry of 2 events, the merge() function will collect attributes of map and merge them to a single map, returned as stockDetails.

clear

Function returns the cleared map.

Syntax

<OBJECT> map:clear(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map which needs to be cleared		OBJECT	No	Yes

EXAMPLE 1

map:clear(stockDetails)

Returns an empty map.

clone

Function returns the cloned map.

Syntax

<OBJECT> map:clone(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map to which needs to be cloned.		OBJECT	No	Yes

EXAMPLE 1

map:clone(stockDetails)

Function returns cloned map of stockDetails.

combineByKey

Function returns the map after combining all the maps given as parameters, such that the keys, of all the maps will be matched with an Array list of values from each map respectively.

Syntax

<OBJECT> map:combineByKey(<OBJECT> map, <OBJECT> map)
<OBJECT> map:combineByKey(<OBJECT> map, <OBJECT> map, <OBJECT> ...)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map into which the key-values need to copied.		OBJECT	No	Yes

EXAMPLE 1

map:combineByKey(map1, map2)

If map2 contains key-value pairs ('symbol': 'GDN'), ('volume' : 100), and if map2 contains key-value pairs ('symbol': 'IBM'), ('price' : 12), then the function returns the map with key value pairs as follows, (symbol: ArrayList('GDN', 'IBM')), (volume: ArrayList(100, null)) and (price: ArrayList(null, 12))

containsKey

Function checks if the map contains the key.

Syntax

<BOOL> map:containsKey(<OBJECT> map, <INT|LONG|FLOAT|DOUBLE|BOOL|STRING> key)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map the needs to be checked on containing the key or not.		OBJECT	No	Yes
key	The key to be checked.		INT LONG FLOAT DOUBLE BOOL STRING	No	Yes

EXAMPLE 1

map:containsKey(stockDetails, '1234')

Returns true if the stockDetails map contains key 1234 else it returns false.

containsValue

Function checks if the map contains the value.

Syntax

<BOOL> map:containsValue(<OBJECT> map, <INT|LONG|FLOAT|DOUBLE|BOOL|STRING> value)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map the needs to be checked on containing the value or not.		OBJECT	No	Yes
value	The value to be checked.		INT LONG FLOAT DOUBLE BOOL STRING	No	Yes

EXAMPLE 1

map:containsValue(stockDetails, 'IBM')

Returns true if the stockDetails map contains value IBM else it returns false.

create

Function creates a map pairing the keys and their corresponding values.

Syntax

<OBJECT> map:create()
<OBJECT> map:create(<OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key1, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> value1)
<OBJECT> map:create(<OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key1, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> value1, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> ...)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
key1	Key 1	-	OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	Yes	Yes
value1	Value 1	-	OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	Yes	Yes

EXAMPLE 1

map:create(1, 'one', 2, 'two', 3, 'three')

This returns a map with keys 1, 2, 3 mapped with their corresponding values, one, two, three.

EXAMPLE 2

map:create()

This returns an empty map.

createFromJSON

Function returns the map created by pairing the keys with their corresponding values given in the JSON string.

Syntax

<OBJECT> map:createFromJSON(<STRING> json.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
json.string	JSON as a string, which is used to create the map.		STRING	No	Yes

EXAMPLE 1

map:createFromJSON("{‘symbol' : 'IBM', 'price' : 200, 'volume' : 100}")

This returns a map with the keys symbol, price, and volume, and their values, IBM, 200 and 100 respectively.

createFromXML

Function returns the map created by pairing the keys with their corresponding values,given as an XML string.

Syntax

<OBJECT> map:createFromXML(<STRING> xml.string)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
xml.string	The XML string, which is used to create the map.		STRING	No	Yes

EXAMPLE 1

map:createFromXML("<stock>
                      <symbol>IBM</symbol>
                      <price>200</price>
                      <volume>100</volume>
                   </stock>")

This returns a map with the keys symbol, price, volume, and with their values IBM, 200 and 100 respectively.

get

Function returns the value corresponding to the given key from the map.

Syntax

<OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> map:get(<OBJECT> map, <INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key)
<OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> map:get(<OBJECT> map, <INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> default.value)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map from where the value should be obtained.		OBJECT	No	Yes
key	The key to fetch the value.		INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes
default.value	The value to be returned if the map does not have the key.		OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	Yes	Yes

EXAMPLE 1

map:get(companyMap, 1)

If the companyMap has key 1 and value ABC in it\'s set of key value pairs. The function returns ABC.

EXAMPLE 2

map:get(companyMap, 2)

If the companyMap does not have any value for key 2 then the function returns null.

EXAMPLE 3

map:get(companyMap, 2, 'two')

If the companyMap does not have any value for key 2 then the function returns two.

isEmpty

Function checks if the map is empty.

Syntax

<BOOL> map:isEmpty(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map the need to be checked whether it\'s empty or not.		OBJECT	No	Yes

EXAMPLE 1

map:isEmpty(stockDetails)

Returns true if the stockDetails map is empty else it returns false.

isMap

Function checks if the object is type of a map.

Syntax

<BOOL> map:isMap(<OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> arg)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
arg	The argument the need to be determined whether it\'s a map or not.		OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes

EXAMPLE 1

map:isMap(stockDetails)

Returns true if the stockDetails is and an instance of java.util.Map else it returns false.

keys

Function to return the keys of the map as a list.

Syntax

<OBJECT> map:keys(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map from which list of keys to be returned.		OBJECT	No	Yes

EXAMPLE 1

map:keys(stockDetails)

Returns keys of the stockDetails map.

put

Function returns the updated map after adding the given key-value pair. If the key already exist in the map the key is updated with the new value.

Syntax

<OBJECT> map:put(<OBJECT> map, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> value)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map to which the value should be added.		OBJECT	No	Yes
key	The key to be added.		OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes
value	The value to be added.		OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes

EXAMPLE 1

map:put(stockDetails , 'IBM' , '200')

Function returns the updated map named stockDetails after adding the value 200 with the key IBM.

putAll

Function returns the updated map after adding all the key-value pairs from another map. If there are duplicate keys, the key will be assigned new values from the map that\'s being copied.

Syntax

<OBJECT> map:putAll(<OBJECT> to.map, <OBJECT> from.map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
to.map	The map into which the key-values need to copied.		OBJECT	No	Yes
from.map	The map from which the key-values are copied.		OBJECT	No	Yes

EXAMPLE 1

map:putAll(toMap, fromMap)

If toMap contains key-value pairs ('symbol': 'GDN'), ('volume' : 100), and if fromMap contains key-value pairs ('symbol': 'IBM'), ('price' : 12), then the function returns updated toMap with key-value pairs ('symbol': 'IBM'), ('price' : 12), ('volume' : 100).

putIfAbsent

Function returns the updated map after adding the given key-value pair if key is absent.

Syntax

<OBJECT> map:putIfAbsent(<OBJECT> map, <INT|LONG|FLOAT|DOUBLE|BOOL|STRING> key, <INT|LONG|FLOAT|DOUBLE|BOOL|STRING> value)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map to which the value should be added.		OBJECT	No	Yes
key	The key to be added.		INT LONG FLOAT DOUBLE BOOL STRING	No	Yes
value	The value to be added.		INT LONG FLOAT DOUBLE BOOL STRING	No	Yes

EXAMPLE 1

map:putIfAbsent(stockDetails , 1234 , 'IBM')

Function returns the updated map named stockDetails after adding the value IBM with the key 1234 if key is absent from the original map.

remove

Function returns the updated map after removing the element with the specified key.

Syntax

<OBJECT> map:remove(<OBJECT> map, <OBJECT|INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map that needs to be updated.		OBJECT	No	Yes
key	The key of the element that needs to removed.		OBJECT INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes

EXAMPLE 1

map:remove(stockDetails, 1234)

This returns the updated map, stockDetails after removing the key-value pair corresponding to the key 1234.

replace

Function returns the updated map after replacing the given key-value pair only if key is present.

Syntax

<OBJECT> map:replace(<OBJECT> map, <INT|LONG|FLOAT|DOUBLE|FLOAT|BOOL|STRING> key, <INT|LONG|FLOAT|DOUBLE|BOOL|STRING> value)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map to which the key-value should be replaced.		OBJECT	No	Yes
key	The key to be replaced.		INT LONG FLOAT DOUBLE FLOAT BOOL STRING	No	Yes
value	The value to be replaced.		INT LONG FLOAT DOUBLE BOOL STRING	No	Yes

EXAMPLE 1

map:replace(stockDetails , 1234 , 'IBM')

Function returns the updated map named stockDetails after replacing the value IBM with the key 1234 if present.

replaceAll

Function returns the updated map after replacing all the key-value pairs from another map, if keys are present.

Syntax

<OBJECT> map:replaceAll(<OBJECT> to.map, <OBJECT> from.map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
to.map	The map into which the key-values need to copied.		OBJECT	No	Yes
from.map	The map from which the key-values are copied.		OBJECT	No	Yes

EXAMPLE 1

map:replaceAll(toMap, fromMap)

If toMap contains key-value pairs ('symbol': 'GDN'), ('volume' : 100), and if fromMap contains key-value pairs ('symbol': 'IBM'), ('price' : 12), then the function returns updated toMap with key-value pairs ('symbol': 'IBM'), ('volume' : 100).

size

Function to return the size of the map.

Syntax

<INT> map:size(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map for which size should be returned.		OBJECT	No	Yes

EXAMPLE 1

map:size(stockDetails)

Returns size of the stockDetails map.

toJSON

Function converts a map into a JSON object and returns the JSON as a string.

Syntax

<STRING> map:toJSON(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map that needs to be converted to JSON		OBJECT	No	Yes

EXAMPLE 1

map:toJSON(company)

If company is a map with key-value pairs, ('symbol': 'GDN'),('volume' : 100), and ('price', 200), it returns the JSON string {"symbol" : "GDN", "volume" : 100 , "price" : 200}.

toXML

Function returns the map as an XML string.

Syntax

<STRING> map:toXML(<OBJECT> map)
<STRING> map:toXML(<OBJECT> map, <OBJECT|STRING> root.element.name)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map that needs to be converted to XML.		OBJECT	No	Yes
root.element.name	The root element of the map.	The XML root element will be ignored	OBJECT STRING	Yes	Yes

EXAMPLE 1

toXML(company, 'abcCompany')

If company is a map with key-value pairs, ('symbol' : 'GDN'), ('volume' : 100), and ('price' : 200), this function returns XML as a string, <abcCompany><symbol>GDN</symbol><volume><100></volume><price>200</price></abcCompany>.

EXAMPLE 2

toXML(company)

If company is a map with key-value pairs, ('symbol' : 'GDN'), ('volume' : 100), and ('price' : 200), this function returns XML without root element as a string, <symbol>GDN</symbol><volume><100></volume><price>200</price>.

values

Function to return the values of the map.

Syntax

<OBJECT> map:values(<OBJECT> map)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	The map from which list if values to be returned.		OBJECT	No	Yes

EXAMPLE 1

map:values(stockDetails)

Returns values of the stockDetails map.

tokenize

Tokenize the map and return each key, value as new attributes in events

Syntax

map:tokenize(<OBJECT> map)
map:tokenize(<OBJECT> map, <OBJECT> ...)

QUERY PARAMETERS

Name	Description	Default Value	Possible Data Types	Optional	Dynamic
map	Hash map containing key value pairs		OBJECT	No	Yes

Extra Return Attributes

Name	Description	Possible Types
key	Key of an entry consisted in the map	OBJECT
value	Value of an entry consisted in the map. If more than one map is given, then an Array List of values from each map is returned for the value attribute.	OBJECT

EXAMPLE 1

CREATE STREAM StockStream (symbol string, price float);

insert into TempStream
select map:collect(symbol, price) as symbolPriceMap
from StockStream#window.lengthBatch(2);

insert into SymbolStream
select key, value
from TempStream#map:tokenize(customMap);

Based on the length batch window, symbolPriceMap will collect two events, and the map will then again tokenized to give 2 events with key and values being symbol name and price respectively.