Interface HttpHeaders

All Superinterfaces:
HttpObject, Iterable<Map.Entry<AsciiString,​String>>
All Known Subinterfaces:
RequestHeaders, ResponseHeaders

public interface HttpHeaders
extends HttpObject
Immutable HTTP/2 headers.

Building a new HttpHeaders

You can use the HttpHeaders.of() factory methods or the HttpHeadersBuilder to build a new HttpHeaders from scratch:


 // Using of()
 HttpHeaders headersWithOf =
     HttpHeaders.of(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=utf-8",
                    HttpHeaderNames.CONTENT_LENGTH, "42");

 // Using builder()
 HttpHeaders headersWithBuilder =
     HttpHeaders.builder()
                .add(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=utf-8")
                .add(HttpHeaderNames.CONTENT_LENGTH, "42")
                .build();

 assert headersWithOf.equals(headersWithBuilder);
 

Building a new HttpHeaders from an existing one

You can use toBuilder() or withMutations(Consumer) to build a new HttpHeaders derived from an existing one:


 HttpHeaders headers = HttpHeaders.of("name1", "value0");

 // Using toBuilder()
 HttpHeaders headersWithToBuilder = headers.toBuilder()
                                           .set("name1", "value1")
                                           .add("name2", "value2")
                                           .build();
 // Using withMutations()
 HttpHeaders headersWithMutations = headers.withMutations(builder -> {
     builder.set("name1", "value1");
     builder.add("name2", "value2");
 });

 assert headersWithToBuilder.equals(headersWithMutations);

 // Note that the original headers remain unmodified.
 assert !headers.equals(headersWithToBuilder);
 assert !headers.equals(headersWithMutations);
 

Specifying a non-String header value

Certain header values are better represented as a Java object than as a String. For example, it is more convenient to specify "content-length", "content-type" and "date" header as Integer, MediaType and Instant (or Date) respectively. Armeria's HTTP header API allows you to specify a Java object of well-known type as a header value by converting it into an HTTP-friendly String representation:

Using HttpHeaders.of() factory methods


 HttpHeaders headers =
     HttpHeaders.of(HttpHeaderNames.CONTENT_LENGTH, 42,
                    HttpHeaderNames.CONTENT_TYPE, MediaType.JSON_UTF_8,
                    HttpHeaderNames.DATE, Instant.now());
 

Using HttpHeadersBuilder


 HttpHeaders headers =
     HttpHeaders.builder()
                .setObject(HttpHeaderNames.CONTENT_LENGTH, 42)
                .setObject(HttpHeaderNames.CONTENT_TYPE, MediaType.JSON_UTF_8)
                .setObject(HttpHeaderNames.DATE, Instant.now())
                .build();
 

Specifying value type explicitly

You might prefer type-safe setters for more efficiency and less ambiguity:


 HttpHeaders headers =
     HttpHeaders.builder()
                .setInt(HttpHeaderNames.CONTENT_LENGTH, 42)
                .set(HttpHeaderNames.CONTENT_TYPE, MediaType.JSON_UTF_8.toString())
                .setTimeMillis(HttpHeaderNames.DATE, System.currentTimeMillis())
                .build();
 
See Also:
RequestHeaders, ResponseHeaders
  • Field Details

  • Method Details

    • builder

      static HttpHeadersBuilder builder()
      Returns a new empty builder.
    • of

      static HttpHeaders of()
      Returns an empty HttpHeaders.
    • of

      static HttpHeaders of​(CharSequence name, String value)
      Returns a new HttpHeaders with the specified header.
    • of

      static HttpHeaders of​(CharSequence name, Object value)
      Returns a new HttpHeaders with the specified header. The value is converted into a String as explained in Specifying a non-String header value.
    • of

      static HttpHeaders of​(CharSequence name1, String value1, CharSequence name2, String value2)
      Returns a new HttpHeaders with the specified headers.
    • of

      static HttpHeaders of​(CharSequence name1, Object value1, CharSequence name2, Object value2)
      Returns a new HttpHeaders with the specified headers. The values are converted into Strings as explained in Specifying a non-String header value.
    • of

      static HttpHeaders of​(CharSequence name1, String value1, CharSequence name2, String value2, CharSequence name3, String value3)
      Returns a new HttpHeaders with the specified headers.
    • of

      static HttpHeaders of​(CharSequence name1, Object value1, CharSequence name2, Object value2, CharSequence name3, Object value3)
      Returns a new HttpHeaders with the specified headers. The values are converted into Strings as explained in Specifying a non-String header value.
    • of

      static HttpHeaders of​(CharSequence name1, String value1, CharSequence name2, String value2, CharSequence name3, String value3, CharSequence name4, String value4)
      Returns a new HttpHeaders with the specified headers.
    • of

      static HttpHeaders of​(CharSequence name1, Object value1, CharSequence name2, Object value2, CharSequence name3, Object value3, CharSequence name4, Object value4)
      Returns a new HttpHeaders with the specified headers. The values are converted into Strings as explained in Specifying a non-String header value.
    • toBuilder

      HttpHeadersBuilder toBuilder()
      Returns a new builder created from the entries of this headers.
      See Also:
      withMutations(Consumer)
    • withMutations

      default HttpHeaders withMutations​(Consumer<HttpHeadersBuilder> mutator)
      Returns a new headers which is the result from the mutation by the specified Consumer. This method is a shortcut for:
      
       builder = toBuilder();
       mutator.accept(builder);
       return builder.build();
       
      See Also:
      toBuilder()
    • isEndOfStream

      boolean isEndOfStream()
      Tells whether the headers correspond to the last frame in an HTTP/2 stream.
    • contentType

      @Nullable MediaType contentType()
      Returns the parsed "content-type" header.
      Returns:
      the parsed MediaType if present and valid, or null otherwise.
    • get

      @Nullable String get​(CharSequence name)
      Returns the value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      the first header value if the header is found, or null if there's no such header
    • get

      String get​(CharSequence name, String defaultValue)
      Returns the value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      defaultValue - the default value
      Returns:
      the first header value or defaultValue if there is no such header
    • getAll

      List<String> getAll​(CharSequence name)
      Returns all values for the header with the specified name. The returned List can't be modified.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      a List of header values or an empty List if there is no such header.
    • getInt

      @Nullable Integer getInt​(CharSequence name)
      Returns the int value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      the int value of the first value in insertion order or null if there is no such header or it can't be converted to int.
    • getInt

      int getInt​(CharSequence name, int defaultValue)
      Returns the int value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      defaultValue - the default value
      Returns:
      the int value of the first value in insertion order or defaultValue if there is no such header or it can't be converted to int.
    • getLong

      @Nullable Long getLong​(CharSequence name)
      Returns the long value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      the long value of the first value in insertion order or null if there is no such header or it can't be converted to long.
    • getLong

      long getLong​(CharSequence name, long defaultValue)
      Returns the long value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      defaultValue - the default value
      Returns:
      the long value of the first value in insertion order or defaultValue if there is no such header or it can't be converted to long.
    • getFloat

      @Nullable Float getFloat​(CharSequence name)
      Returns the float value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      the float value of the first value in insertion order or null if there is no such header or it can't be converted to float.
    • getFloat

      float getFloat​(CharSequence name, float defaultValue)
      Returns the float value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      defaultValue - the default value
      Returns:
      the float value of the first value in insertion order or defaultValue if there is no such header or it can't be converted to float.
    • getDouble

      @Nullable Double getDouble​(CharSequence name)
      Returns the double value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      the double value of the first value in insertion order or null if there is no such header or it can't be converted to double.
    • getDouble

      double getDouble​(CharSequence name, double defaultValue)
      Returns the double value of a header with the specified name. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      defaultValue - the default value
      Returns:
      the double value of the first value in insertion order or defaultValue if there is no such header or it can't be converted to double.
    • getTimeMillis

      @Nullable Long getTimeMillis​(CharSequence name)
      Returns the value of a header with the specified name in milliseconds. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      Returns:
      the milliseconds value of the first value in insertion order or null if there is no such header or it can't be converted to milliseconds.
    • getTimeMillis

      long getTimeMillis​(CharSequence name, long defaultValue)
      Returns the value of a header with the specified name in milliseconds. If there are more than one value for the specified name, the first value in insertion order is returned.
      Parameters:
      name - the name of the header to retrieve
      defaultValue - the default value
      Returns:
      the milliseconds value of the first value in insertion order or defaultValue if there is no such header or it can't be converted to milliseconds.
    • contains

      boolean contains​(CharSequence name)
      Returns true if a header with the name exists, false otherwise.
      Parameters:
      name - the header name
    • contains

      boolean contains​(CharSequence name, String value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value of the header to find
    • containsObject

      boolean containsObject​(CharSequence name, Object value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value
      Returns:
      true if the header exists. false otherwise
    • containsInt

      boolean containsInt​(CharSequence name, int value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value
      Returns:
      true if the header exists. false otherwise
    • containsLong

      boolean containsLong​(CharSequence name, long value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value
      Returns:
      true if the header exists. false otherwise
    • containsFloat

      boolean containsFloat​(CharSequence name, float value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value
      Returns:
      true if the header exists. false otherwise
    • containsDouble

      boolean containsDouble​(CharSequence name, double value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value
      Returns:
      true if the header exists. false otherwise
    • containsTimeMillis

      boolean containsTimeMillis​(CharSequence name, long value)
      Returns true if a header with the name and value exists.
      Parameters:
      name - the header name
      value - the header value
      Returns:
      true if the header exists. false otherwise
    • size

      int size()
      Returns the number of headers.
    • isEmpty

      boolean isEmpty()
      Returns true if this headers does not contain any entries.
    • names

      Set<AsciiString> names()
      Returns a Set of all header names. The returned Set cannot be modified.
    • iterator

      Returns an Iterator that yields all header entries. The iteration order is as follows:
      1. All pseudo headers (order not specified).
      2. All non-pseudo headers (in insertion order).
      Specified by:
      iterator in interface Iterable<Map.Entry<AsciiString,​String>>
    • valueIterator

      Iterator<String> valueIterator​(CharSequence name)
      Returns an Iterator that yields all values of the headers with the specified name.
    • forEach

      void forEach​(BiConsumer<AsciiString,​String> action)
      Invokes the specified action for all header entries.
    • forEachValue

      void forEachValue​(CharSequence name, Consumer<String> action)
      Invokes the specified action for all values of the headers with the specified name.
    • stream

      default Stream<Map.Entry<AsciiString,​String>> stream()
      Returns a Stream that yields all header entries.
    • valueStream

      default Stream<String> valueStream​(CharSequence name)
      Returns a Stream that yields all values of the headers with the specified name.