/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.undertow.attribute;
import io.undertow.server.HttpServerExchange;
/**
* Representation of a string attribute from a HTTP server exchange.
*
*
* @author Stuart Douglas
*/
public interface ExchangeAttribute {
/**
* Resolve the attribute from the HTTP server exchange. This may return null if the attribute is not present.
* @param exchange The exchange
* @return The attribute
*/
String readAttribute(final HttpServerExchange exchange);
/**
* Sets a new value for the attribute. Not all attributes are writable.
* @param exchange The exchange
* @param newValue The new value for the attribute
* @throws ReadOnlyAttributeException when attribute cannot be written
*/
void writeAttribute(final HttpServerExchange exchange, final String newValue) throws ReadOnlyAttributeException;
}