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 * 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
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 *  Unless required by applicable law or agreed to in writing, software
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package io.undertow.attribute;

import io.undertow.server.HttpServerExchange;
import io.undertow.util.HeaderValues;
import io.undertow.util.HttpString;

A response header
Author:Stuart Douglas
/** * A response header * * @author Stuart Douglas */
public class ResponseHeaderAttribute implements ExchangeAttribute { private final HttpString responseHeader; public ResponseHeaderAttribute(final HttpString responseHeader) { this.responseHeader = responseHeader; } @Override public String readAttribute(final HttpServerExchange exchange) { HeaderValues header = exchange.getResponseHeaders().get(responseHeader); if (header == null) { return null; } else if(header.size() == 1) { return header.getFirst(); } StringBuilder sb = new StringBuilder(); sb.append("["); for (int i = 0; i < header.size(); ++i) { if (i != 0) { sb.append(", "); } sb.append(header.get(i)); } sb.append("]"); return sb.toString(); } @Override public void writeAttribute(final HttpServerExchange exchange, final String newValue) throws ReadOnlyAttributeException { exchange.getResponseHeaders().put(responseHeader, newValue); } public static final class Builder implements ExchangeAttributeBuilder { @Override public String name() { return "Response header"; } @Override public ExchangeAttribute build(final String token) { if (token.startsWith("%{o,") && token.endsWith("}")) { final HttpString headerName = HttpString.tryFromString(token.substring(4, token.length() - 1)); return new ResponseHeaderAttribute(headerName); } return null; } @Override public int priority() { return 0; } } }