Apache Nifi Expression language allows dynmic values in functional fields. This is a short reference to find useful functions and examples. For a full reference see the
offical documentation
.
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Reserved Charecters
If these charecters are present in attribute names they need to be quoted
$ | { } ( ) [ ] , : ; / * ' (space) \t \r \n
Ex.
${'a:attribute name'} ${"a:attribute name"}
Type Conversion
Coerces from one format to another
toString${ literal(2):toString():equals('2') }
toNumber${ literal('2'):toNumber():equals(2) }
toDecimal${ filesize:toDecimal() }
plus${ fileSize:plus(10) }
minus${ fileSize:minus(10) }
multiply${ fileSize:multiply(10) }
divide${ fileSize:divide(10) }
mod${ fileSize:mod(10) }
toRadix${ fileSize:toRadix(10) }
isNull${ filename:isNull() }
notNull${ filename:notNull() }
isEmpty${ literal(''):isEmpty() }
equals(string)${ filename:equals('value') }
equalsIgnoreCase(string)${ filename:equalsIgnoreCase('value') }
gt(number)${ fileSize:gt(64) }
ge(number)${ fileSize:ge(64) }
lt(number)${ fileSize:lt(64) }
le(number)${ fileSize:le(64) }
and(bool)${ fileSize:gt(64):and( ${fileSize:lt(128)} )}
or(bool)${ fileSize:lt(64):or( ${fileSize:gt(128)} )}
not${ filename:endsWith('csv'):not() } }
ifElse('true val', 'false val')${ filename:endsWith('csv'):ifElse('is csv', 'is not csv') }
Encode/Decode Functions
${message:
function()
}
Functions: escapeJson, escapeXml, escapeCsv, escapeHtml3, escapeHtml4, unescapeJson, unescapeXml, unescapeCsv, unescapeHtml3, unescapeHtml4, urlEncode, urlDecode, base64Encode, base64Decode
Text Search
filename:equal('fizz buzz bazz.txt')
startsWith(
string
)${ filename:startsWith('fizz') }
endsWith(
string
)${ filename:endsWith('txt') }
contains(
string
)${ filename:contains('buzz') }
in(
string, string...
)${ literal('NO'):in('NO','NOT') }
indexOf(
string
)${ filename:indexOf('buzz') }
5
lastIndexOf(
string
)${ filename:lastIndexOf('z') }
13
find(
regex
)${ filename:find('.*zz') }
matches(
regex
)${ filename:matches('fizz.*txt') }
jsonPath(
path
)${ theJson:jsonPath('$.attribute') }
format(format,
zone
)${ aDate:format('yyyy/MM/dd', 'GMT') }
toDate(format,
zone
)${ literal('1999/12/31'):toDate('yyyy/MM/dd', 'GMT') }
now()${now():toNumber()
milliseconds since epoch
toUpper${ filename:toUpper() }
toLower${ filename:toLower() }
trim${ literal('abc '):trim() }
'abc'
substring(
start
,
end
)${ filename:substring(0, 3) }
'abc'
substringBefore(string)${ filename:substringBefore('zz') }
'fi'
substringBeforeLast(string)${ filename:substringBeforeLast('zz') }
'fizz buzz ba'
substringAfter(string)${ filename:substringAfter('zz') }
' buzz bazz.txt'
substringAfterLast(string)${ filename:substringAfterLast('zz') }
'.txt'
getDelimitedField( index,
delimeter, quote char, escape char, strip char
)${ filename:getDelimitedField(2, ' ') }
buzz
append(string)${ filename:append('.bck') }
'fizz buzz bazz.txt.bck'
prepend(string)${ filename:prepend('a ') }
'a fizz buzz bazz.txt'
replace(search, replace)${ filename:replace(' ','_') }
fizz_buzz_bazz.txt
replaceFirst(search, replace${ filename:(' ', '_') }
fizz_buzz bazz.txt
replaceAll(regex, replace)${ filename:replaceAll('(\w{4})\s', '!$1') }
!fizz!buzzbazz.txt
replaceNull(replace)${ idonotexist:('abc'):replaceNull('abc') }
'abc'
replaceEmpty(replace)${ literal(''):replaceEmpty('abc') }
'abc'
length${ filename:length() }
18
${ ip() }local ip
${ hostname(
bool
) }${ hostname(true) }
fully qualified hostname
${ UUID() }unique generated UUID
${ nextInt() }system wide counter, not maintained through restart
${ literal(value) }${ literal(2):gt(1) }
${ getStateValue(key) }${ getStateValue('hash') }
${ thread() }Thread name
anyAttribute('attr1', 'attr2'...)${ anyAttribute('bizz', 'bazz'):contains('value') }
allAttributes('attr1', 'attr2'...)${ allAttributes('bizz', 'bazz'):contains('value') }
anyMatchingAttribute(regex)${ anyMatchingAttributes('b.*zz'):contains('value') }
allMatchingAttributes(regex)${ allMatchingAttributes('b.*zz'):contains('value') }
anyDelineatedValue(value, delimiter)${ anyDelineatedValue(${literal('a-b-c')}, '-'):contains('a') }
allDelineatedValues(value, delimiter)${ allDelineatedValues(${literal('a-b-c')}, '-'):contains('a) }
false
join(string)${ allAttributes('attr1', 'attr2'):join(', ') }
count()
