org.fosstrak.ale.server.type.FileSubscriberOutputChannel.java Source code

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Here is the source code for org.fosstrak.ale.server.type.FileSubscriberOutputChannel.java

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/*
 * Copyright (C) 2007 ETH Zurich
 *
 * This file is part of Fosstrak (www.fosstrak.org).
 *
 * Fosstrak is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software Foundation.
 *
 * Fosstrak 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Fosstrak; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */
package org.fosstrak.ale.server.type;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URI;

import org.apache.log4j.Logger;
import org.fosstrak.ale.exception.ImplementationException;
import org.fosstrak.ale.exception.InvalidURIException;
import org.fosstrak.ale.xsd.ale.epcglobal.ECReports;
import org.springframework.util.StringUtils;

/**
 * deliver a message using a file.
 * @author swieland
 */
public class FileSubscriberOutputChannel extends AbstractSubscriberOutputChannel {

    /** logger */
    private static final Logger LOG = Logger.getLogger(FileSubscriberOutputChannel.class);

    /** localhost */
    private static final String LOCALHOST = "localhost";

    private URI uri;
    private final String host;
    private final String path;

    public FileSubscriberOutputChannel(String notificationURI) throws InvalidURIException {
        super(notificationURI);
        try {
            uri = new URI(notificationURI.replaceAll("\\\\", "/"));
            path = StringUtils.startsWithIgnoreCase(uri.getPath(), "/") ? uri.getPath().substring(1)
                    : uri.getPath();
            if ("".equalsIgnoreCase(path) || StringUtils.endsWithIgnoreCase(path, "/")) {
                throw new InvalidURIException("missing filename");
            }
            host = (uri.getHost() == null) ? LOCALHOST.toLowerCase() : uri.getHost();
            if (!(LOCALHOST.equalsIgnoreCase(getHost()))) {
                throw new InvalidURIException("This implementation can not write reports to a remote file.");
            }
            if (!("FILE".equalsIgnoreCase(uri.getScheme()))) {
                LOG.error("invalid scheme: " + uri.getScheme());
                throw new InvalidURIException("invalid scheme: " + uri.getScheme());
            }
        } catch (Exception e) {
            LOG.error("malformed URI");
            throw new InvalidURIException("malformed URI: ", e);
        }
    }

    @Override
    public boolean notify(ECReports reports) throws ImplementationException {
        writeNotificationToFile(reports);
        return true;
    }

    /**
     * This method writes ec reports to a file.
     * 
     * @param reports to write to the file
     * @throws ImplementationException if an implementation exception occures
     */
    private void writeNotificationToFile(ECReports reports) throws ImplementationException {
        // append reports as xml to file
        LOG.debug("Append reports '" + reports.getSpecName() + "' as xml to file '" + getPath() + "'.");

        File file = getFile();

        // create file if it does not already exists
        if (!file.exists() || !file.isFile()) {
            try {
                file.createNewFile();
            } catch (IOException e) {
                throw new ImplementationException("Could not create new file '" + getPath() + "'.", e);
            }
        }

        try {

            // open streams
            FileOutputStream fileOutputStream = new FileOutputStream(file, true);
            DataOutputStream dataOutputStream = new DataOutputStream(fileOutputStream);

            // append reports as xml to file
            dataOutputStream.writeBytes(getPrettyXml(reports));
            dataOutputStream.writeBytes("\n\n");
            dataOutputStream.flush();

            // close streams
            dataOutputStream.close();
            fileOutputStream.close();

        } catch (IOException e) {
            throw new ImplementationException("Could not write to file '" + getPath() + "'.", e);
        }
    }

    protected File getFile() {
        return new File(getPath());
    }

    public String getHost() {
        return host;
    }

    public String getPath() {
        return path;
    }

    @Override
    public String toString() {
        return uri.toString();
    }
}