Package com.linecorp.armeria.common

Interface AttributesSetters

All Known Subinterfaces:
AttributesBuilder, ConcurrentAttributes
@UnstableApi public interface AttributesSetters
Sets entries for building an Attributes or updating ConcurrentAttributes.

  • Method Details

    • set

      <T> AttributesSetters set(AttributeKey<T> key, @Nullable T value)
      Sets the specified value with the given AttributeKey. The old value associated with the AttributeKey is replaced by the specified value. If a null value is specified, the value in the AttributesGetters.parent() is hidden as well. 
      
 static final AttributeKey<String> USER_ID = AttributeKey.valueOf("USER_ID");
 static final AttributeKey<String> SECRET_TOKEN = AttributeKey.valueOf("SECRET_TOKEN");
 static final AttributeKey<String> TRACE_ID = AttributeKey.valueOf("TRACE_ID");

 Attributes attributes = Attributes.of(USER_ID, "Meri Kim",
                                       SECRET_TOKEN, "secret-1",
                                       TRACE_ID, "trace-1");

 Attributes child = Attributes.builder(attributes)
                              .set(SECRET_TOKEN, null)
                              .set(TRACE_ID, "trace-2")
                              .build();

 // Any mutations in the child do not modify the value in the parent.
 assert attributes.attr(USER_ID).equals("Meri Kim");
 assert attributes.attr(SECRET_TOKEN).equals("secret-1");
 assert attributes.attr(TRACE_ID).equals("trace-1");

 // Inherits the value of USER_ID from the parent.
 assert child.attr(USER_ID).equals("Meri Kim");
 // Hides the value of SECRET_TOKEN that the parent has.
 assert child.attr(SECRET_TOKEN) == null;
 // Overrides the parent's TRACE_ID.
 assert child.attr(TRACE_ID).equals("trace-2");

    • getAndSet

      @Nullable <T> T getAndSet(AttributeKey<T> key, @Nullable T value)
      Sets the specified value with the given AttributeKey. The old value associated with the AttributeKey is replaced by the specified value. If a null value is specified, the value in the AttributesGetters.parent() is hidden as well. 
      
 static final AttributeKey<String> USER_ID = AttributeKey.valueOf("USER_ID");
 static final AttributeKey<String> SECRET_TOKEN = AttributeKey.valueOf("SECRET_TOKEN");
 static final AttributeKey<String> TRACE_ID = AttributeKey.valueOf("TRACE_ID");

 Attributes attributes = Attributes.of(USER_ID, "Meri Kim",
                                       SECRET_TOKEN, "secret-1",
                                       TRACE_ID, "trace-1");

 AttributesBuilder newAttributesBuilder = attributes.toBuilder();
 assert newAttributesBuilder.getAndSet(SECRET_TOKEN, null).equals("secret-1")
 assert newAttributesBuilder.getAndSet(TRACE, "trace-2").equals("trace-2")
 Attributes newAttributes = newAttributesBuilder.build();

 // Any mutations in the child do not modify the value in the original attributes.
 assert attributes.attr(USER_ID).equals("Meri Kim");
 assert attributes.attr(SECRET_TOKEN).equals("secret-1");
 assert attributes.attr(TRACE_ID).equals("trace-1");

 // Copies the value from the original attribute.
 assert newAttributes.attr(USER_ID).equals("Meri Kim");
 // Removes the value of the original attribute.
 assert newAttributes.attr(SECRET_TOKEN) == null;
 // Overrides the value of the original attribute.
 assert newAttributes.attr(TRACE_ID).equals("trace-2");
      Returns:
      the previous value associated with the AttributeKey, or null if there was no mapping for the AttributeKey. A null can be returned if the AttributeKey is previously associated with null.

    • remove

      <T> boolean remove(AttributeKey<T> key)
      Removes the value associated with the specified AttributeKey in the AttributesGetters.ownAttrs().

      Note that this method won't remove the value in AttributesGetters.parent(). 

      
 static final AttributeKey<String> USER_ID = AttributeKey.valueOf("USER_ID");
 static final AttributeKey<String> SECRET_TOKEN = AttributeKey.valueOf("SECRET_TOKEN");
 static final AttributeKey<String> TRACE_ID = AttributeKey.valueOf("TRACE_ID");

 Attributes attributes = Attributes.of(USER_ID, "Meri Kim", SECRET_TOKEN, "secret-1");

 AttributesBuilder newAttributesBuilder = attributes.toBuilder();
 assert newAttributesBuilder.remove(USER_ID);
 assert !newAttributesBuilder.remove(TRACE_ID);

 AttributesBuilder childAttributes =
     Attributes.builder(attributes)
               .set(TRACE_ID, "secret-2")
               .remove(USER_ID)
               .remove(TRACE_ID)
               .build();

 assert attributes.attr(TRACE_ID) == null;
 // The value in the parent will not be removed.
 assert attributes.attr(USER_ID).equals("Meri Kim");
      Returns:
      true if the value associated the AttributeKey has been removed.

    • removeAndThen

      default <T> AttributesSetters removeAndThen(AttributeKey<T> key)
      Removes the value associated with the specified AttributeKey in the AttributesGetters.ownAttrs(). Unlike remove(AttributeKey) this method returns itself so that the caller can chain the invocations.

      Note that this method won't remove the value in AttributesGetters.parent().