net.myrrix.web.servlets.IngestServlet.java Source code

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Here is the source code for net.myrrix.web.servlets.IngestServlet.java

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/*
 * Copyright Myrrix Ltd
 *
 * 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 net.myrrix.web.servlets;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Collection;
import java.util.NoSuchElementException;
import java.util.zip.GZIPInputStream;
import java.util.zip.ZipInputStream;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;

import com.google.common.base.Charsets;
import com.google.common.net.HttpHeaders;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.mahout.cf.taste.common.TasteException;

import net.myrrix.common.MyrrixRecommender;

/**
 * <p>Responds to a POST request to {@code /ingest} and in turn calls
 * {@link MyrrixRecommender#ingest(Reader)}}. The content of the request body is
 * fed to this method. Note that the content may be gzipped; if so, header "Content-Encoding"
 * must have value "gzip".</p>
 *
 * <p>Alternatively, CSV data may be POSTed here as if part of a web browser file upload. In this case
 * the "Content-Type" should be "multipart/form-data", and the payload encoded accordingly. The uploaded
 * file may be gzipped or zipped.</p>
 *
 * @author Sean Owen
 * @since 1.0
 */
public final class IngestServlet extends AbstractMyrrixServlet {

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        MyrrixRecommender recommender = getRecommender();

        boolean fromBrowserUpload = request.getContentType().startsWith("multipart/form-data");

        Reader reader;
        if (fromBrowserUpload) {

            Collection<Part> parts = request.getParts();
            if (parts == null || parts.isEmpty()) {
                response.sendError(HttpServletResponse.SC_BAD_REQUEST, "No form data");
                return;
            }
            Part part = parts.iterator().next();
            String partContentType = part.getContentType();
            InputStream in = part.getInputStream();
            if ("application/zip".equals(partContentType)) {
                in = new ZipInputStream(in);
            } else if ("application/gzip".equals(partContentType)) {
                in = new GZIPInputStream(in);
            } else if ("application/x-gzip".equals(partContentType)) {
                in = new GZIPInputStream(in);
            } else if ("application/bzip2".equals(partContentType)) {
                in = new BZip2CompressorInputStream(in);
            } else if ("application/x-bzip2".equals(partContentType)) {
                in = new BZip2CompressorInputStream(in);
            }
            reader = new InputStreamReader(in, Charsets.UTF_8);

        } else {

            String charEncodingName = request.getCharacterEncoding();
            Charset charEncoding = charEncodingName == null ? Charsets.UTF_8 : Charset.forName(charEncodingName);
            String contentEncoding = request.getHeader(HttpHeaders.CONTENT_ENCODING);
            if (contentEncoding == null) {
                reader = request.getReader();
            } else if ("gzip".equals(contentEncoding)) {
                reader = new InputStreamReader(new GZIPInputStream(request.getInputStream()), charEncoding);
            } else if ("zip".equals(contentEncoding)) {
                reader = new InputStreamReader(new ZipInputStream(request.getInputStream()), charEncoding);
            } else if ("bzip2".equals(contentEncoding)) {
                reader = new InputStreamReader(new BZip2CompressorInputStream(request.getInputStream()),
                        charEncoding);
            } else {
                response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Unsupported Content-Encoding");
                return;
            }

        }

        try {
            recommender.ingest(reader);
        } catch (IllegalArgumentException iae) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, iae.toString());
            return;
        } catch (NoSuchElementException nsee) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, nsee.toString());
            return;
        } catch (TasteException te) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, te.toString());
            getServletContext().log("Unexpected error in " + getClass().getSimpleName(), te);
            return;
        }

        String referer = request.getHeader(HttpHeaders.REFERER);
        if (fromBrowserUpload && referer != null) {
            // Parsing avoids response splitting
            response.sendRedirect(new URL(referer).toString());
        }

    }

}