com.bitplan.vzjava.resources.PowerPlotResource.java Source code

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Here is the source code for com.bitplan.vzjava.resources.PowerPlotResource.java

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/**
 * Copyright (c) 2017 BITPlan GmbH
 *
 * http://www.bitplan.com
 *
 * This file is part of the Opensource project at:
 * https://github.com/WolfgangFahl/com.bitplan.vzjava
 *
 * 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 com.bitplan.vzjava.resources;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.text.ParseException;
import java.util.Date;
import java.util.Locale;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.ws.rs.DefaultValue;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;

import org.apache.commons.lang3.time.DateUtils;

import com.bitplan.vzjava.PowerValuePlotManager;

@SuppressWarnings("rawtypes")
@Path("/plot")
public class PowerPlotResource extends VZResource {
    protected static Logger LOGGER = Logger.getLogger("com.bitplan.vzjava.resources");

    /**
     * Power Plot Resource constructor
     */
    public PowerPlotResource() {
        super.prepareRootMap("Plot", "Plot");
    }

    @GET
    @Path("/range/{isoFrom}/{isoTo}/plot")
    @Produces("image/png")
    public Response getPlotFileForRange(@HeaderParam("If-Modified-Since") String modified,
            @QueryParam("width") @DefaultValue("1024") int width,
            @QueryParam("height") @DefaultValue("768") int height, @QueryParam("channelnos") String channelNos,
            @PathParam("isoFrom") String isoFrom, @PathParam("isoTo") String isoTo) throws Exception {
        File pngFile = PowerValuePlotManager.getInstance().getPlot(channelNos, isoFrom, isoTo, width, height);
        Response result = returnFile(pngFile, modified);
        return result;
    }

    @GET
    @Path("/file/{filename}")
    public Response getPlotFileForRange(@HeaderParam("If-Modified-Since") String modified,
            @PathParam("filename") String filename) throws Exception {
        File pngFile = PowerValuePlotManager.getInstance().getPlotFile(filename);
        Response result = returnFile(pngFile, modified);
        return result;
    }

    @GET
    @Path("/range/{isoFrom}/{isoTo}")
    public Response getPlotForRange(@QueryParam("width") @DefaultValue("1024") int width,
            @QueryParam("height") @DefaultValue("768") int height, @QueryParam("channelnos") String channelNos,
            @PathParam("isoFrom") String isoFrom, @PathParam("isoTo") String isoTo) throws Exception {
        File pngFile = PowerValuePlotManager.getInstance().getPlot(channelNos, isoFrom, isoTo, width, height);
        rootMap.put("isoFrom", isoFrom);
        rootMap.put("isoTo", isoTo);
        rootMap.put("pngFile", pngFile.getName());
        return super.templateResponse("plot.rythm");
    }

    /**
     * http://stackoverflow.com/a/10257341/1497139
     * Sends the file if modified and "not modified" if not modified
     * future work may put each file with a unique id in a separate folder in
     * tomcat
     * * use that static URL for each file
     * * if file is modified, URL of file changes
     * * -> client always fetches correct file
     * 
     * method header for calling method public Response
     * getXY(@HeaderParam("If-Modified-Since") String modified) {
     * 
     * @param file
     *          to send
     * @param modified
     *          - HeaderField "If-Modified-Since" - may be "null"
     * @return Response to be sent to the client
     */
    public static Response returnFile(File file, String modified) {
        if (!file.exists()) {
            return Response.status(Status.NOT_FOUND).build();
        }

        // do we really need to send the file or can send "not modified"?
        if (modified != null) {
            Date modifiedDate = null;

            // we have to switch the locale to ENGLISH as parseDate parses in the
            // default locale
            Locale old = Locale.getDefault();
            Locale.setDefault(Locale.ENGLISH);
            try {
                modifiedDate = DateUtils.parseDate(modified, DEFAULT_PATTERNS);
            } catch (ParseException e) {
                LOGGER.log(Level.WARNING, e.getMessage());
            }
            Locale.setDefault(old);

            if (modifiedDate != null) {
                // modifiedDate does not carry milliseconds, but fileDate does
                // therefore we have to do a range-based comparison
                // 1000 milliseconds = 1 second
                if (file.lastModified() - modifiedDate.getTime() < DateUtils.MILLIS_PER_SECOND) {
                    return Response.status(Status.NOT_MODIFIED).build();
                }
            }
        }
        // we really need to send the file

        try {
            Date fileDate = new Date(file.lastModified());
            return Response.ok(new FileInputStream(file)).lastModified(fileDate).build();
        } catch (FileNotFoundException e) {
            return Response.status(Status.NOT_FOUND).build();
        }
    }

    /**
     * Date format pattern used to parse HTTP date headers in RFC 1123 format.
     */
    public static final String PATTERN_RFC1123 = "EEE, dd MMM yyyy HH:mm:ss zzz";

    /**
     * Date format pattern used to parse HTTP date headers in RFC 1036 format.
     */
    public static final String PATTERN_RFC1036 = "EEEE, dd-MMM-yy HH:mm:ss zzz";

    /**
     * Date format pattern used to parse HTTP date headers in ANSI C
     * <code>asctime()</code> format.
     */
    public static final String PATTERN_ASCTIME = "EEE MMM d HH:mm:ss yyyy";

    public static final String[] DEFAULT_PATTERNS = new String[] { PATTERN_RFC1036, PATTERN_RFC1123,
            PATTERN_ASCTIME };

}