Http header names java

HTTP request and response headers are represented by this class which implements the interface Map < String , List >. The keys are case-insensitive Strings representing the header names and the value associated with each key is a List with one element for each occurrence of the header name in the request or response. For example, if a response header instance contains one key «HeaderName» with two values «value1 and value2» then this object is output as two header lines:

HeaderName: value1 HeaderName: value2

getFirst(String) returns a single valued header or the first value of a multi-valued header.
add(String,String) adds the given header value to the list for the given key
set(String,String) sets the given header field to the single value given overwriting any existing values in the value list.

Nested Class Summary

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

Constructor Summary

Method Summary

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Constructor Detail

Headers

Method Detail

size

Returns the number of key-value mappings in this map. If the map contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

isEmpty

containsKey

Returns true if this map contains a mapping for the specified key. More formally, returns true if and only if this map contains a mapping for a key k such that (key==null ? k==null : key.equals(k)). (There can be at most one such mapping.)

containsValue

Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the map size for most implementations of the Map interface.

get

Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key. More formally, if this map contains a mapping from a key k to a value v such that (key==null ? k==null : key.equals(k)) , then this method returns v ; otherwise it returns null . (There can be at most one such mapping.) If this map permits null values, then a return value of null does not necessarily indicate that the map contains no mapping for the key; it’s also possible that the map explicitly maps the key to null . The containsKey operation may be used to distinguish these two cases.

getFirst

put

public ListString> put(String key, ListString> value)

Associates the specified value with the specified key in this map (optional operation). If the map previously contained a mapping for the key, the old value is replaced by the specified value. (A map m is said to contain a mapping for a key k if and only if m.containsKey(k) would return true.)

add

adds the given value to the list of headers for the given key. If the mapping does not already exist, then it is created

set

sets the given value as the sole header value for the given key. If the mapping does not already exist, then it is created

remove

Removes the mapping for a key from this map if it is present (optional operation). More formally, if this map contains a mapping from key k to value v such that (key==null ? k==null : key.equals(k)) , that mapping is removed. (The map can contain at most one such mapping.) Returns the value to which this map previously associated the key, or null if the map contained no mapping for the key. If this map permits null values, then a return value of null does not necessarily indicate that the map contained no mapping for the key; it’s also possible that the map explicitly mapped the key to null. The map will not contain a mapping for the specified key once the call returns.

putAll

public void putAll(MapString,? extends ListString>> t)

Copies all of the mappings from the specified map to this map (optional operation). The effect of this call is equivalent to that of calling put(k, v) on this map once for each mapping from key k to value v in the specified map. The behavior of this operation is undefined if the specified map is modified while the operation is in progress.

clear

Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.

keySet

Returns a Set view of the keys contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator’s own remove operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll, and clear operations. It does not support the add or addAll operations.

values

Returns a Collection view of the values contained in this map. The collection is backed by the map, so changes to the map are reflected in the collection, and vice-versa. If the map is modified while an iteration over the collection is in progress (except through the iterator’s own remove operation), the results of the iteration are undefined. The collection supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Collection.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

entrySet

public SetMap.EntryString,ListString>>> entrySet()

Returns a Set view of the mappings contained in this map. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator’s own remove operation, or through the setValue operation on a map entry returned by the iterator) the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the Iterator.remove, Set.remove, removeAll, retainAll and clear operations. It does not support the add or addAll operations.

equals

It is reflexive: for any non-null reference value x , x.equals(x) should return true .
It is symmetric: for any non-null reference values x and y , x.equals(y) should return true if and only if y.equals(x) returns true .
It is transitive: for any non-null reference values x , y , and z , if x.equals(y) returns true and y.equals(z) returns true , then x.equals(z) should return true .
It is consistent: for any non-null reference values x and y , multiple invocations of x.equals(y) consistently return true or consistently return false , provided no information used in equals comparisons on the objects is modified.
For any non-null reference value x , x.equals(null) should return false .

hashCode

Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
If two objects are equal according to the equals(Object) method, then calling the hashCode method on each of the two objects must produce the same integer result.
It is not required that if two objects are unequal according to the Object.equals(java.lang.Object) method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

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Class HttpHeaders

An HttpHeaders is not typically created directly, but rather returned from an HttpRequest or an HttpResponse . Specific HTTP headers can be set for a request through one of the request builder’s headers methods.

The methods of this class ( that accept a String header name ), and the Map returned by the map method, operate without regard to case when retrieving the header value(s).

An HTTP header name may appear more than once in the HTTP protocol. As such, headers are represented as a name and a list of values. Each occurrence of a header value is added verbatim, to the appropriate header name list, without interpreting its value. In particular, HttpHeaders does not perform any splitting or joining of comma separated header value strings. The order of elements in a header value list is preserved when building a request. For responses, the order of elements in a header value list is the order in which they were received. The Map returned by the map method, however, does not provide any guarantee with regard to the ordering of its entries.

HttpHeaders instances are immutable.

Method Summary

Returns an Optional containing the first header string value of the given named (and possibly multi-valued) header.

Methods declared in class java.lang.Object

Method Details

firstValue

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

firstValueAsLong

Returns an OptionalLong containing the first header string value of the named header field. If the header is not present, then the Optional is empty. If the header is present but contains a value that does not parse as a Long value, then an exception is thrown.

allValues

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

map

equals

Tests this HTTP headers instance for equality with the given object. If the given object is not an HttpHeaders then this method returns false . Two HTTP headers are equal if each of their corresponding maps are equal. This method satisfies the general contract of the Object.equals method.

hashCode

Computes a hash code for this HTTP headers instance. The hash code is based upon the components of the HTTP headers map , and satisfies the general contract of the Object.hashCode method.

toString

of

Returns an HTTP headers from the given map. The given map’s key represents the header name, and its value the list of string header values for that header name. An HTTP header name may appear more than once in the HTTP protocol. Such, multi-valued, headers must be represented by a single entry in the given map, whose entry value is a list that represents the multiple header string values. Leading and trailing whitespaces are removed from all string values retrieved from the given map and its lists before processing. Only headers that, after filtering, contain at least one, possibly empty string, value will be added to the HTTP headers.

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