org.n52.tamis.rest.forward.processes.ProcessesRequestForwarder.java Source code

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Here is the source code for org.n52.tamis.rest.forward.processes.ProcessesRequestForwarder.java

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/**
 * Copyright (C) 2016-2016 52North Initiative for Geospatial Open Source
 * Software GmbH
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License version 2 as publishedby the Free
 * Software Foundation.
 *
 * If the program is linked with libraries which are licensed under one of the
 * following licenses, the combination of the program with the linked library is
 * not considered a "derivative work" of the program:
 *
 *     - Apache License, version 2.0
 *     - Apache Software License, version 1.0
 *     - GNU Lesser General Public License, version 3
 *     - Mozilla Public License, versions 1.0, 1.1 and 2.0
 *     - Common Development and Distribution License (CDDL), version 1.0
 *
 * Therefore the distribution of the program linked with libraries licensed under
 * the aforementioned licenses, is permitted by the copyright holders if the
 * distribution is compliant with both the GNU General Public License version 2
 * and the aforementioned licenses.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU General Public License for more details.
 */
package org.n52.tamis.rest.forward.processes;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.n52.tamis.core.javarepresentations.processes.ProcessDescription_forProcessList;
import org.n52.tamis.core.javarepresentations.processes.Processes_Tamis;
import org.n52.tamis.core.urlconstants.URL_Constants_TAMIS;
import org.n52.tamis.core.urlconstants.URL_Constants_WpsProxy;
import org.n52.tamis.rest.controller.ParameterValueStore;
import org.n52.tamis.rest.forward.AbstractRequestForwarder;
import org.n52.tamis.rest.forward.capabilities.CapabilitiesRequestForwarder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.client.RestTemplate;

/**
 * Class to delegate a processes overview request to the WPS proxy.
 * 
 * @author Christian Danowski (contact: c.danowski@52north.org)
 *
 */
public class ProcessesRequestForwarder extends AbstractRequestForwarder {

    private static final Logger logger = LoggerFactory.getLogger(CapabilitiesRequestForwarder.class);

    /**
     * {@inheritDoc} <br/>
     * <br/>
     * Delegates an incoming processes (overview) request to the WPS proxy,
     * receives the extended processes document and creates an instance of
     * {@link Processes_Tamis}
     * 
     * @param parameterValueStore
     *            must contain the URL variable
     *            {@link URL_Constants_TAMIS#SERVICE_ID_VARIABLE_NAME} to
     *            identify the WPS instance
     * @return an instance of {@link Processes_Tamis}
     */
    public final Processes_Tamis forwardRequestToWpsProxy(HttpServletRequest request, Object requestBody,
            ParameterValueStore parameterValueStore) {
        // assure that the URL variable "serviceId" is existent
        initializeRequestSpecificParameters(parameterValueStore);

        String processes_url_wpsProxy = createTargetURL_WpsProxy(request);

        RestTemplate processesTemplate = new RestTemplate();

        // fetch extended processesDoc from WPS proxy and deserialize it into
        // shortened processesDoc
        Processes_Tamis processesDoc = processesTemplate.getForObject(processes_url_wpsProxy,
                Processes_Tamis.class);

        /*
         * set the URL.
         * 
         * construct it via the requestURL from HttpServletRequest object and
         * append the process identifier.
         */
        setUrls(processesDoc, request.getRequestURL());

        return processesDoc;
    }

    /**
     * 
     * @param processesDoc
     * @param requestURL
     *            the request URL ends on ".../processes"
     */
    private void setUrls(Processes_Tamis processesDoc, StringBuffer requestURL) {

        /*
         * set the URL.
         * 
         * construct it from the requestURL from HttpServletRequest object and
         * the process identifier.
         * 
         * the request URL ends on ".../processes", hence for each process we
         * have to append the process identifier.
         */

        List<ProcessDescription_forProcessList> processes = processesDoc.getProcesses();
        for (ProcessDescription_forProcessList processDescription : processes) {
            processDescription.setUrl(requestURL + "/" + processDescription.getId());
        }
    }

    @Override
    protected void initializeRequestSpecificParameters(ParameterValueStore parameterValueStore) {
        super.initializeRequestSpecificParameters(parameterValueStore);
    }

    @Override
    protected String setUpTargetUrl_WithSameBaseUrl(String contextURL) {
        /*
         * The difference between contextURL of TAMIS interface and the
         * targetURL of the WPS proxy is a prefix + service number:
         * 
         * contexURL: "<baseURL>/constantServicePrefix/{service_id}/processes"
         * 
         * targetURL: "<baseURL>/processes"
         */

        String targetURL = contextURL.split(URL_Constants_TAMIS.TAMIS_PREFIX)[0];
        targetURL = targetURL + URL_Constants_WpsProxy.SLASH_PROCESSES;

        return targetURL;
    }

    @Override
    protected String setUpTargetUrl_WithDifferentBaseUrl(String baseURL_WpsProxy) {
        return baseURL_WpsProxy + URL_Constants_WpsProxy.PROCESSES;
    }

}