JSONBinding.java

/**
 * Copyright (C) 2012-2017 52°North 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 published
 * by 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.sos.binding;

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

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.n52.sos.coding.OperationKey;
import org.n52.sos.coding.json.JSONConstants;
import org.n52.sos.decode.Decoder;
import org.n52.sos.decode.OperationDecoderKey;
import org.n52.sos.exception.HTTPException;
import org.n52.sos.exception.ows.NoApplicableCodeException;
import org.n52.sos.exception.ows.concrete.NoDecoderForKeyException;
import org.n52.sos.ogc.ows.OwsExceptionReport;
import org.n52.sos.request.AbstractServiceRequest;
import org.n52.sos.response.AbstractServiceResponse;
import org.n52.sos.util.JSONUtils;
import org.n52.sos.util.http.MediaType;
import org.n52.sos.util.http.MediaTypes;

import com.fasterxml.jackson.databind.JsonNode;

/**
 * TODO JavaDoc
 *
 * @author Christian Autermann <c.autermann@52north.org>
 * @since 4.0.0
 */
public class JSONBinding extends SimpleBinding {
    private static final String URL_PATTERN = "/json";
    private static final Set<String> CONFORMANCE_CLASSES = Collections
            .singleton("http://www.opengis.net/spec/SOS/2.0/conf/json");
    private static final Logger LOG = LoggerFactory.getLogger(JSONBinding.class);

    @Override
    public String getUrlPattern() {
        return URL_PATTERN;
    }

    @Override
    public Set<MediaType> getSupportedEncodings() {
        return Collections.singleton(MediaTypes.APPLICATION_JSON);
    }

    @Override
    public Set<String> getConformanceClasses() {
        return Collections.unmodifiableSet(CONFORMANCE_CLASSES);
    }

    @Override
    protected boolean isUseHttpResponseCodes() {
        return true;
    }

    @Override
    protected MediaType getDefaultContentType() {
        return MediaTypes.APPLICATION_JSON;
    }

    @Override
    public boolean checkOperationHttpPostSupported(OperationKey k) throws HTTPException {
        return getDecoder(new OperationDecoderKey(k, MediaTypes.APPLICATION_JSON)) != null;
    }

    @Override
    public void doPostOperation(HttpServletRequest req, HttpServletResponse res)
            throws HTTPException, IOException {
        AbstractServiceRequest<?> request = null;
        try {
            request = parseRequest(req);
            checkServiceOperatorKeyTypes(request);
            AbstractServiceResponse response = getServiceOperator(request).receiveRequest(request);
            writeResponse(req, res, response);
        } catch (OwsExceptionReport oer) {
            oer.setVersion(request != null ? request.getVersion() : null);
            writeOwsExceptionReport(req, res, oer);
        }
    }

    private AbstractServiceRequest<?> parseRequest(HttpServletRequest request)
            throws OwsExceptionReport {
        try {
            JsonNode json = JSONUtils.loadReader(request.getReader());
            if (LOG.isDebugEnabled()) {
                LOG.debug("JSON-REQUEST: {}", JSONUtils.print(json));
            }
            OperationDecoderKey key = new OperationDecoderKey(
                    json.path(JSONConstants.SERVICE).textValue(),
                    json.path(JSONConstants.VERSION).textValue(),
                    json.path(JSONConstants.REQUEST).textValue(),
                    MediaTypes.APPLICATION_JSON);
            Decoder<AbstractServiceRequest<?>, JsonNode> decoder =
                    getDecoder(key);
            if (decoder == null) {
                throw new NoDecoderForKeyException(key);
            }
            AbstractServiceRequest<?> sosRequest = decoder.decode(json);
            sosRequest.setRequestContext(getRequestContext(request));
            return sosRequest;
        } catch (IOException ioe) {
            throw new NoApplicableCodeException().causedBy(ioe).withMessage(
                    "Error while reading request! Message: %s", ioe.getMessage());
        }
    }
}