org.apache.logging.log4j.util

Interface ReadOnlyStringMap

All Superinterfaces:

Serializable

All Known Subinterfaces:

IndexedReadOnlyStringMap, IndexedStringMap, StringMap

All Known Implementing Classes:

DefaultThreadContextMap, SortedArrayStringMap

public interface ReadOnlyStringMap
extends Serializable

A read-only collection of String keys mapped to values of arbitrary type.

Since:

2.7

Method Summary

Modifier and Type	Method and Description
boolean	containsKey(String key) Returns true if this data structure contains the specified key, false otherwise.
<V> void	forEach(BiConsumer<String,? super V> action) Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.
<V,S> void	forEach(TriConsumer<String,? super V,S> action, S state) Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.
<V> V	getValue(String key) Returns the value for the specified key, or null if the specified key does not exist in this collection.
boolean	isEmpty() Returns true if this collection is empty (size is zero), false otherwise.
int	size() Returns the number of key-value pairs in this collection.
Map<String,String>	toMap() Returns a non-null mutable Map<String, String> containing a snapshot of this data structure.

Method Detail

toMap

Map<String,String> toMap()

Returns a non-null mutable Map<String, String> containing a snapshot of this data structure.

Returns:

a mutable copy of this data structure in Map<String, String> form.

containsKey

boolean containsKey(String key)

Returns true if this data structure contains the specified key, false otherwise.

Parameters:

key - the key whose presence to check. May be null.

Returns:

true if this data structure contains the specified key, false otherwise.

forEach

<V> void forEach(BiConsumer<String,? super V> action)

Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.

Some implementations may not support structural modifications (adding new elements or removing elements) while iterating over the contents. In such implementations, attempts to add or remove elements from the BiConsumer's BiConsumer.accept(Object, Object) accept} method may cause a ConcurrentModificationException to be thrown.

Type Parameters:

V - type of the value.

Parameters:

action - The action to be performed for each key-value pair in this collection.

Throws:

ConcurrentModificationException - some implementations may not support structural modifications to this data structure while iterating over the contents with forEach(BiConsumer) or forEach(TriConsumer, Object).

forEach

<V,S> void forEach(TriConsumer<String,? super V,S> action,
                   S state)

Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.

The third parameter lets callers pass in a stateful object to be modified with the key-value pairs, so the TriConsumer implementation itself can be stateless and potentially reusable.

Some implementations may not support structural modifications (adding new elements or removing elements) while iterating over the contents. In such implementations, attempts to add or remove elements from the TriConsumer's accept method may cause a ConcurrentModificationException to be thrown.

Type Parameters:

V - type of the value.

S - type of the third parameter.

Parameters:

action - The action to be performed for each key-value pair in this collection.

state - the object to be passed as the third parameter to each invocation on the specified triconsumer.

Throws:

ConcurrentModificationException - some implementations may not support structural modifications to this data structure while iterating over the contents with forEach(BiConsumer) or forEach(TriConsumer, Object).

getValue

<V> V getValue(String key)

Returns the value for the specified key, or null if the specified key does not exist in this collection.

Parameters:

key - the key whose value to return.

Returns:

the value for the specified key or null.

isEmpty

boolean isEmpty()

Returns true if this collection is empty (size is zero), false otherwise.

Returns:

true if this collection is empty (size is zero).

size

int size()

Returns the number of key-value pairs in this collection.

Returns:

the number of key-value pairs in this collection.