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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
 *
 *  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.
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package io.undertow.server.handlers;

import io.undertow.UndertowMessages;
import io.undertow.attribute.ExchangeAttribute;
import io.undertow.attribute.ExchangeAttributes;
import io.undertow.server.HandlerWrapper;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.builder.HandlerBuilder;
import io.undertow.util.HttpString;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

Set a fixed response header.
Author:Stuart Douglas
/** * Set a fixed response header. * * @author Stuart Douglas */
public class SetHeaderHandler implements HttpHandler { private final HttpString header; private final ExchangeAttribute value; private final HttpHandler next; public SetHeaderHandler(final String header, final String value) { if(value == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("value"); } if(header == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("header"); } this.next = ResponseCodeHandler.HANDLE_404; this.value = ExchangeAttributes.constant(value); this.header = new HttpString(header); } public SetHeaderHandler(final HttpHandler next, final String header, final ExchangeAttribute value) { if(value == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("value"); } if(header == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("header"); } if(next == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("next"); } this.next = next; this.value = value; this.header = new HttpString(header); } public SetHeaderHandler(final HttpHandler next, final String header, final String value) { if(value == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("value"); } if(header == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("header"); } if(next == null) { throw UndertowMessages.MESSAGES.argumentCannotBeNull("next"); } this.next = next; this.value = ExchangeAttributes.constant(value); this.header = new HttpString(header); } @Override public void handleRequest(final HttpServerExchange exchange) throws Exception { exchange.getResponseHeaders().put(header, value.readAttribute(exchange)); next.handleRequest(exchange); } public ExchangeAttribute getValue() { return value; } public HttpString getHeader() { return header; } @Override public String toString() { return "set( header='" + header.toString() + "', value='" + value.toString() + "' )"; } public static class Builder implements HandlerBuilder { @Override public String name() { return "header"; } @Override public Map<String, Class<?>> parameters() { Map<String, Class<?>> parameters = new HashMap<>(); parameters.put("header", String.class); parameters.put("value", ExchangeAttribute.class); return parameters; } @Override public Set<String> requiredParameters() { final Set<String> req = new HashSet<>(); req.add("value"); req.add("header"); return req; } @Override public String defaultParameter() { return null; } @Override public HandlerWrapper build(final Map<String, Object> config) { final ExchangeAttribute value = (ExchangeAttribute) config.get("value"); final String header = (String) config.get("header"); return new HandlerWrapper() { @Override public HttpHandler wrap(HttpHandler handler) { return new SetHeaderHandler(handler, header, value); } }; } } }