io.pivotalservices.wiretaprouteservice.CatchAllController.java Source code

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Here is the source code for io.pivotalservices.wiretaprouteservice.CatchAllController.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 io.pivotalservices.wiretaprouteservice;

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;
import java.util.List;

/**
 * The application needs at least one controller in order for the Requests and Responses to be intercepted.
 * This controller is mapped to all endpoints, and so gets triggered no matter what the incoming request as long as
 * it contains the desired headers. It is possible to add further logging here.
 */
@RestController
final class CatchAllController {

    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 static Logger logger = LoggerFactory.getLogger(CatchAllController.class);

    private final RestOperations restOperations;

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

    @RequestMapping(headers = { FORWARDED_URL, PROXY_METADATA, PROXY_SIGNATURE })
    ResponseEntity<?> service(RequestEntity<byte[]> incoming) {
        printHeaders("INCOMING", incoming.getHeaders());
        RequestEntity<?> outgoing = getOutgoingRequest(incoming);
        printHeaders("OUTGOING", incoming.getHeaders());
        return this.restOperations.exchange(outgoing, byte[].class);
    }

    private static void printHeaders(String type, HttpHeaders headers) {
        StringBuilder sb = new StringBuilder(type + " HEADER ");
        sb.append(System.lineSeparator());

        for (String key : headers.keySet()) {
            List<String> values = headers.getValuesAsList(key);
            sb.append("KEY: " + key + " VALUES: ");

            for (String value : values) {
                sb.append(value + "; ");
            }
            sb.append(System.lineSeparator());
        }
        logger.debug(sb.toString());
    }

    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);
    }

}