Apache Nifi Expression Language Cheat Sheet
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() } |
Mathematical
| plus | ${ fileSize:plus(10) } |
| minus | ${ fileSize:minus(10) } |
| multiply | ${ fileSize:multiply(10) } |
| divide | ${ fileSize:divide(10) } |
| mod | ${ fileSize:mod(10) } |
| toRadix | ${ fileSize:toRadix(10) } |
Logic Operators
| 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') } |
Date/Time
format is the java SimpleDateFormat
| 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 |
String Manipulation
filename:equal('fizz buzz bazz.txt')
| 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 |
Utilities
These subjectless functions provide useful utilities.
| ${ 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 |
Multiple Attributes
| 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() |