Package io.helidon.webserver

Interface Parameters

All Known Subinterfaces:

Headers, RequestHeaders, ResponseHeaders

All Known Implementing Classes:

ReadOnlyParameters

public interface Parameters

Parameters represents key : value pairs where key is a String with potentially multiple values.

This structure represents query parameters, headers and path parameters in ServerRequest and ServerResponse.

Interface focus on most convenient use cases in HTTP Request and Response processing, like

 
 // Get and map with default
 .first("count").map(Integer::new).orElse(0);
 // Find max in multiple values
 .all("counts").stream().mapToInt(Integer::valueOf).max().orElse(0);
 
 

Mutable operations are defined in two forms:

• put... create or replace association.
• add... create association or add values to existing association.

It is possible to use toMap() method to get immutable map view of data.

Various static factory methods can be used to create common implementations.

Method Summary

Modifier and Type	Method	Description
void	add(java.lang.String key, java.lang.Iterable<java.lang.String> values)	Adds specified values tu association with the specified key (optional operation).
void	add(java.lang.String key, java.lang.String... values)	Adds specified values tu association with the specified key (optional operation).
void	addAll(Parameters parameters)	Copies all of the mappings from the specified parameters to this instance adding values to existing associations (optional operation).
java.util.List<java.lang.String>	all(java.lang.String name)	Returns an unmodifiable List of all of the values of the given named parameter.
java.util.List<java.lang.String>	computeIfAbsent(java.lang.String key, java.util.function.Function<java.lang.String,java.lang.Iterable<java.lang.String>> values)	If the specified key is not already associated with a value computes new association using the given function and returns empty List, else returns the current value (optional operation).
java.util.List<java.lang.String>	computeSingleIfAbsent(java.lang.String key, java.util.function.Function<java.lang.String,java.lang.String> value)	If the specified key is not already associated with a value computes new association using the given function and returns empty List, else returns the current value (optional operation).
java.util.Optional<java.lang.String>	first(java.lang.String name)	Returns an Optional containing the first value of the given parameter (and possibly multi-valued) parameter.
java.util.List<java.lang.String>	put(java.lang.String key, java.lang.Iterable<java.lang.String> values)	Associates specified values with the specified key (optional operation).
java.util.List<java.lang.String>	put(java.lang.String key, java.lang.String... values)	Associates specified values with the specified key (optional operation).
void	putAll(Parameters parameters)	Copies all of the mappings from the specified parameters to this instance replacing values of existing associations (optional operation).
java.util.List<java.lang.String>	putIfAbsent(java.lang.String key, java.lang.Iterable<java.lang.String> values)	If the specified key is not already associated with a value associates it with the given value and returns empty List, else returns the current value (optional operation).
java.util.List<java.lang.String>	putIfAbsent(java.lang.String key, java.lang.String... values)	If the specified key is not already associated with a value associates it with the given value and returns empty List, else returns the current value (optional operation).
java.util.List<java.lang.String>	remove(java.lang.String key)	Removes the mapping for a key if it is present (optional operation).
java.util.Map<java.lang.String,java.util.List<java.lang.String>>	toMap()	Returns a copy of parameters as a Map.
static Parameters	toUnmodifiableParameters(Parameters parameters)	Returns an unmodifiable view.

Method Detail

first

java.util.Optional<java.lang.String> first(java.lang.String name)

Returns an Optional containing the first value of the given parameter (and possibly multi-valued) parameter. If the parameter is not present, then the returned Optional is empty.

Parameters:

name - the parameter name

Returns:

an Optional<V> for the first named value

Throws:

java.lang.NullPointerException - if name is null

all

java.util.List<java.lang.String> all(java.lang.String name)

Returns an unmodifiable List of all of the values of the given named parameter. Always returns a List, which may be empty if the parameter is not present.

Parameters:

name - the parameter name

Returns:

a List of values with zero or greater size

Throws:

java.lang.NullPointerException - if name is null

put

java.util.List<java.lang.String> put(java.lang.String key,
                                     java.lang.String... values)

Associates specified values with the specified key (optional operation). If parameters previously contained a mapping for the key, the old values fully replaced.

Parameters:

key - key with which the specified value is to be associated

values - value to be associated with the specified key

Returns:

the previous values associated with key, or empty List if there was no mapping for key.

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

put

java.util.List<java.lang.String> put(java.lang.String key,
                                     java.lang.Iterable<java.lang.String> values)

Associates specified values with the specified key (optional operation). If parameters previously contained a mapping for the key, the old values fully replaced.

Parameters:

key - key with which the specified value is to be associated

values - value to be associated with the specified key. If null then association will be removed.

Returns:

the previous values associated with key, or empty List if there was no mapping for key.

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

putIfAbsent

java.util.List<java.lang.String> putIfAbsent(java.lang.String key,
                                             java.lang.String... values)

If the specified key is not already associated with a value associates it with the given value and returns empty List, else returns the current value (optional operation).

Parameters:

key - key with which the specified value is to be associated

values - value to be associated with the specified key

Returns:

the previous values associated with key, or empty List if there was no mapping for key.

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

putIfAbsent

java.util.List<java.lang.String> putIfAbsent(java.lang.String key,
                                             java.lang.Iterable<java.lang.String> values)

If the specified key is not already associated with a value associates it with the given value and returns empty List, else returns the current value (optional operation).

Parameters:

key - key with which the specified value is to be associated

values - value to be associated with the specified key

Returns:

the previous values associated with key, or empty List if there was no mapping for key.

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

computeIfAbsent

java.util.List<java.lang.String> computeIfAbsent(java.lang.String key,
                                                 java.util.function.Function<java.lang.String,java.lang.Iterable<java.lang.String>> values)

If the specified key is not already associated with a value computes new association using the given function and returns empty List, else returns the current value (optional operation).

Parameters:

key - key with which the specified value is to be associated

values - value to be associated with the specified key

Returns:

the current (potentially computed) values associated with key, or empty List if function returns null

Throws:

java.lang.NullPointerException - if the specified key is null

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters)

java.lang.IllegalStateException - if the computation detectably attempts a recursive update to this map that would otherwise never complete

java.lang.RuntimeException - or Error if the mappingFunction does so, in which case the mapping is left unestablished

computeSingleIfAbsent

java.util.List<java.lang.String> computeSingleIfAbsent(java.lang.String key,
                                                       java.util.function.Function<java.lang.String,java.lang.String> value)

If the specified key is not already associated with a value computes new association using the given function and returns empty List, else returns the current value (optional operation).

Parameters:

key - a key with which the specified value is to be associated

value - a single value to be associated with the specified key

Returns:

the current (potentially computed) values associated with key, or empty List if function returns null

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

java.lang.IllegalStateException - if the computation detectably attempts a recursive update to this map that would otherwise never complete

java.lang.RuntimeException - or Error if the mappingFunction does so, in which case the mapping is left unestablished

putAll

void putAll(Parameters parameters)

Copies all of the mappings from the specified parameters to this instance replacing values of existing associations (optional operation).

Parameters:

parameters - to copy.

Throws:

java.lang.NullPointerException - if the specified parameters are null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

add

void add(java.lang.String key,
         java.lang.String... values)

Adds specified values tu association with the specified key (optional operation). If parameters doesn't contains mapping, new mapping is created.

Parameters:

key - key with which the specified value is to be associated

values - value to be add to association with the specified key

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

add

void add(java.lang.String key,
         java.lang.Iterable<java.lang.String> values)

Adds specified values tu association with the specified key (optional operation). If parameters doesn't contains mapping, new mapping is created.

Parameters:

key - key with which the specified value is to be associated

values - value to be add to association with the specified key. If null then noting will be add.

Throws:

java.lang.NullPointerException - if the specified key is null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

addAll

void addAll(Parameters parameters)

Copies all of the mappings from the specified parameters to this instance adding values to existing associations (optional operation).

Parameters:

parameters - to copy.

Throws:

java.lang.NullPointerException - if the specified parameters are null.

java.lang.UnsupportedOperationException - if put operation is not supported (unmodifiable Parameters).

remove

java.util.List<java.lang.String> remove(java.lang.String key)

Removes the mapping for a key if it is present (optional operation).

Parameters:

key - key whose mapping is to be removed.

Returns:

the previous value associated with key, or empty List.

toMap

java.util.Map<java.lang.String,java.util.List<java.lang.String>> toMap()

Returns a copy of parameters as a Map. This interface should only be used when it is required to iterate over the entire set of parameters.

Returns:

the Map

toUnmodifiableParameters

static Parameters toUnmodifiableParameters(Parameters parameters)

Returns an unmodifiable view.

Parameters:

parameters - a parameters for unmodifiable view.

Returns:

An unmodifiable view.

Throws:

java.lang.NullPointerException - if parameter parameters is null.