nl.dtls.fairdatapoint.api.controller.utils.HttpHeadersUtils.java Source code

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Here is the source code for nl.dtls.fairdatapoint.api.controller.utils.HttpHeadersUtils.java

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package nl.dtls.fairdatapoint.api.controller.utils;

import java.io.IOException;
import javax.servlet.http.HttpServletResponse;
import org.apache.logging.log4j.LogManager;
import org.openrdf.rio.RDFFormat;
import org.springframework.http.MediaType;

/**
 * Handles http headers
 * 
 * @author Rajaram Kaliyaperumal
 * @since 2016-01-07
 * @version 0.1
 */
public class HttpHeadersUtils {

    private final static org.apache.logging.log4j.Logger LOGGER = LogManager.getLogger(HttpHeadersUtils.class);

    public final static String[] SUPPORTED_HEADERS = { "text/turtle", "application/ld+json", "application/rdf+xml",
            "text/n3" };

    /**
     * Set response header for the internal server errors
     * 
     * @param response  Http response
     * @param ex    Server exception
     * @return returns null (as a response body)
     */
    public static String set500ResponseHeaders(HttpServletResponse response, Exception ex) {
        String errorMessage = ("Internal server error; Error message : " + ex.getMessage());
        response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
        try {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, errorMessage);
        } catch (IOException ex1) {
            LOGGER.warn(
                    "Error setting error message for internal server " + "error; The error : " + ex1.getMessage());
        }
        response.setContentType(MediaType.TEXT_PLAIN_VALUE);
        return null;
    }

    /**
     * Set response header for the successful call
     * 
     * @param responseBody ResponseBody
     * @param response  Http response
     * @param requesetedContentType Requeseted ContentType(i.e Accept header)
     */
    public static void set200ResponseHeaders(String responseBody, HttpServletResponse response,
            RDFFormat requesetedContentType) {
        if (responseBody == null) {
            response.setStatus(HttpServletResponse.SC_NOT_FOUND);
            response.setContentType(MediaType.TEXT_PLAIN_VALUE);
        } else {
            response.setStatus(HttpServletResponse.SC_OK);
            response.setContentType(requesetedContentType.getDefaultMIMEType());
        }
    }

    public static RDFFormat getRequestedAcceptHeader(String contentType) {
        RDFFormat requesetedContentType = null;
        if (contentType == null || contentType.isEmpty()) {
            requesetedContentType = RDFFormat.TURTLE;
        } else if (contentType.contentEquals(RDFFormat.TURTLE.getDefaultMIMEType())
                || contentType.contains(MediaType.ALL_VALUE)) {
            requesetedContentType = RDFFormat.TURTLE;
        } else if (contentType.contentEquals(RDFFormat.JSONLD.getDefaultMIMEType())) {
            requesetedContentType = RDFFormat.JSONLD;
        } else if (contentType.contentEquals(RDFFormat.N3.getDefaultMIMEType())) {
            requesetedContentType = RDFFormat.N3;
        } else if (contentType.contentEquals(RDFFormat.RDFXML.getDefaultMIMEType())) {
            requesetedContentType = RDFFormat.RDFXML;
        }
        return requesetedContentType;
    }

}