org.apache.nifi.attribute.expression.language

Class ValueLookup

java.lang.Object

org.apache.nifi.attribute.expression.language.ValueLookup

All Implemented Interfaces:

Map<String,String>

final class ValueLookup
extends Object
implements Map<String,String>

A convenience class to encapsulate the logic of variable substitution based first on any additional variable maps, then flow file properties, then flow file attributes, and finally the provided variable registry.

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields

Modifier and Type	Field and Description
(package private) List<Map<String,String>>	maps
(package private) VariableRegistry	registry

Constructor Summary

Constructors

Constructor and Description
ValueLookup(VariableRegistry registry, FlowFile flowFile, Map<String,String>... additionalMaps) Constructs a ValueLookup where values are looked up first based any provided additional maps, then flowfile properties, then flowfile attributes, then based on the provided variable registry.

Method Summary

Modifier and Type	Method and Description
void	clear()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set<Map.Entry<String,String>>	entrySet()
(package private) static Map<String,String>	extractFlowFileProperties(FlowFile flowFile)
String	get(Object key)
boolean	isEmpty()
Set<String>	keySet()
String	put(String key, String value)
void	putAll(Map<? extends String,? extends String> m)
String	remove(Object key)
int	size()
Collection<String>	values()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

Field Detail

maps

final List<Map<String,String>> maps

registry

final VariableRegistry registry

Constructor Detail

ValueLookup

ValueLookup(VariableRegistry registry,
            FlowFile flowFile,
            Map<String,String>... additionalMaps)

Constructs a ValueLookup where values are looked up first based any provided additional maps, then flowfile properties, then flowfile attributes, then based on the provided variable registry. The lookup is immutable and operations which attempt to alter state will throw UnsupportedOperationException

Parameters:

registry - the variable registry to lookup from; may be null

flowFile - the flowFile to pull attributes from; may be null

additionalMaps - the maps to pull values from; may be null or empty

Method Detail

extractFlowFileProperties

static final Map<String,String> extractFlowFileProperties(FlowFile flowFile)

size

public int size()

Specified by:

size in interface Map<String,String>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<String,String>

containsKey

public boolean containsKey(Object key)

Specified by:

containsKey in interface Map<String,String>

containsValue

public boolean containsValue(Object value)

Specified by:

containsValue in interface Map<String,String>

get

public String get(Object key)

Specified by:

get in interface Map<String,String>

put

public String put(String key,
                  String value)

Specified by:

put in interface Map<String,String>

remove

public String remove(Object key)

Specified by:

remove in interface Map<String,String>

putAll

public void putAll(Map<? extends String,? extends String> m)

Specified by:

putAll in interface Map<String,String>

clear

public void clear()

Specified by:

clear in interface Map<String,String>

keySet

public Set<String> keySet()

Specified by:

keySet in interface Map<String,String>

values

public Collection<String> values()

Specified by:

values in interface Map<String,String>

entrySet

public Set<Map.Entry<String,String>> entrySet()

Specified by:

entrySet in interface Map<String,String>