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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.
 */

package io.undertow.server.handlers;

import java.io.IOException;
import java.util.Collections;
import java.util.Map;
import java.util.Set;

import io.undertow.UndertowLogger;
import io.undertow.io.IoCallback;
import io.undertow.io.Sender;
import io.undertow.predicate.Predicate;
import io.undertow.predicate.Predicates;
import io.undertow.server.HandlerWrapper;
import io.undertow.server.handlers.builder.HandlerBuilder;
import io.undertow.server.protocol.http.HttpContinue;
import io.undertow.server.HttpHandler;
import io.undertow.server.HttpServerExchange;

Handler that provides support for HTTP/1.1 continue responses.

If the provided predicate returns true then the request will be
accepted, otherwise it will be rejected.
If no predicate is supplied then all requests will be accepted.
Author:
Stuart Douglas
See Also:
HttpContinue/**
 * Handler that provides support for HTTP/1.1 continue responses.
 * <p>
 * If the provided predicate returns <code>true</code> then the request will be
 * accepted, otherwise it will be rejected.
 *
 * If no predicate is supplied then all requests will be accepted.
 *
 * @see io.undertow.server.protocol.http.HttpContinue
 * @author Stuart Douglas
 */
public class HttpContinueAcceptingHandler implements HttpHandler {

    private final HttpHandler next;
    private final Predicate accept;

    public HttpContinueAcceptingHandler(HttpHandler next, Predicate accept) {
        this.next = next;
        this.accept = accept;
    }

    public HttpContinueAcceptingHandler(HttpHandler next) {
        this(next, Predicates.truePredicate());
    }

    @Override
    public void handleRequest(final HttpServerExchange exchange) throws Exception {
        if(HttpContinue.requiresContinueResponse(exchange)) {
            if(accept.resolve(exchange)) {
                HttpContinue.sendContinueResponse(exchange, new IoCallback() {
                    @Override
                    public void onComplete(final HttpServerExchange exchange, final Sender sender) {
                        exchange.dispatch(next);
                    }

                    @Override
                    public void onException(final HttpServerExchange exchange, final Sender sender, final IOException exception) {
                        UndertowLogger.REQUEST_IO_LOGGER.ioException(exception);
                        exchange.endExchange();
                    }
                });

            } else {
                HttpContinue.rejectExchange(exchange);
            }
        } else {
            next.handleRequest(exchange);
        }
    }

    public static final class Wrapper implements HandlerWrapper {

        private final Predicate predicate;

        public Wrapper(Predicate predicate) {
            this.predicate = predicate;
        }

        @Override
        public HttpHandler wrap(HttpHandler handler) {
            return new HttpContinueAcceptingHandler(handler, predicate);
        }
    }

    public static class Builder implements HandlerBuilder {

        @Override
        public String name() {
            return "http-continue-accept";
        }

        @Override
        public Map<String, Class<?>> parameters() {
            return Collections.emptyMap();
        }

        @Override
        public Set<String> requiredParameters() {
            return null;
        }

        @Override
        public String defaultParameter() {
            return null;
        }

        @Override
        public HandlerWrapper build(Map<String, Object> config) {
            return new Wrapper(Predicates.truePredicate());
        }
    }
}