org.cloudfoundry.example.Controller.java Source code

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Here is the source code for org.cloudfoundry.example.Controller.java

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/*
 * Copyright 2016 the original author or authors.
 *
 * 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 org.cloudfoundry.example;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestOperations;

import java.net.URI;

@RestController
final class Controller {

    static final String FORWARDED_URL = "X-CF-Forwarded-Url";

    static final String PROXY_METADATA = "X-CF-Proxy-Metadata";

    static final String PROXY_SIGNATURE = "X-CF-Proxy-Signature";

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    private final RestOperations restOperations;

    @Autowired
    Controller(RestOperations restOperations) {
        this.restOperations = restOperations;
    }

    @RequestMapping(headers = { FORWARDED_URL, PROXY_METADATA, PROXY_SIGNATURE })
    ResponseEntity<?> service(RequestEntity<byte[]> incoming) {
        this.logger.info("Incoming Request: {}", incoming);

        RequestEntity<?> outgoing = getOutgoingRequest(incoming);
        this.logger.info("Outgoing Request: {}", outgoing);

        return this.restOperations.exchange(outgoing, byte[].class);
    }

    private static RequestEntity<?> getOutgoingRequest(RequestEntity<?> incoming) {
        HttpHeaders headers = new HttpHeaders();
        headers.putAll(incoming.getHeaders());

        URI uri = headers.remove(FORWARDED_URL).stream().findFirst().map(URI::create)
                .orElseThrow(() -> new IllegalStateException(String.format("No %s header present", FORWARDED_URL)));

        return new RequestEntity<>(incoming.getBody(), headers, incoming.getMethod(), uri);
    }

}