Implementing HTTP byte-range requests in Spring 4 and other framework...

gistfile1.java

package lan.dk.podcastserver.controller.api;

import lan.dk.podcastserver.business.ItemBusiness;
import lan.dk.podcastserver.entity.Item;
import lan.dk.podcastserver.exception.PodcastNotFoundException;
import lan.dk.podcastserver.manager.ItemDownloadManager;
import lan.dk.podcastserver.utils.facade.PageRequestFacade;
import lan.dk.podcastserver.utils.multipart.MultipartFileSender;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URISyntaxException;
import java.text.ParseException;

/**
 * Created by kevin on 26/12/2013. 
 * See full code here : https://github.com/davinkevin/Podcast-Server/blob/d927d9b8cb9ea1268af74316cd20b7192ca92da7/src/main/java/lan/dk/podcastserver/controller/api/ItemController.java
 */
@RestController
@RequestMapping("/api/podcast/{idPodcast}/items")
public class ItemController {

    protected final Logger logger = LoggerFactory.getLogger(this.getClass());
    
    @Resource private ItemBusiness itemBusiness;

    @Autowired
    protected ItemDownloadManager itemDownloadManager;

    @RequestMapping(value="{id:[\\d]+}/download{ext}", method = RequestMethod.GET)
    public void getEpisodeFile(@PathVariable Integer id, HttpServletRequest request, HttpServletResponse response) throws Exception {
        logger.debug("Download du fichier d'item {}", id);
        Item item = itemBusiness.findOne(id);
        if (item.isDownloaded()) {
            logger.debug("Récupération en local de l'item {} au chemin {}", id, item.getLocalUri());
            MultipartFileSender.fromPath(item.getLocalPath())
                    .with(request)
                    .with(response)
                .serveResource();
        } else {
            response.sendRedirect(item.getUrl());
        }
    }
}

MultipartFileSender

package lan.dk.podcastserver.utils.multipart;

import lan.dk.podcastserver.utils.MimeTypeUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.FileTime;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * Created by kevin on 10/02/15.
 * See full code here : https://github.com/davinkevin/Podcast-Server/blob/d927d9b8cb9ea1268af74316cd20b7192ca92da7/src/main/java/lan/dk/podcastserver/utils/multipart/MultipartFileSender.java
 */
public class MultipartFileSender {

    protected final Logger logger = LoggerFactory.getLogger(this.getClass());
    
    private static final int DEFAULT_BUFFER_SIZE = 20480; // ..bytes = 20KB.
    private static final long DEFAULT_EXPIRE_TIME = 604800000L; // ..ms = 1 week.
    private static final String MULTIPART_BOUNDARY = "MULTIPART_BYTERANGES";
    
    Path filepath;
    HttpServletRequest request;
    HttpServletResponse response;
    
    public MultipartFileSender() {
    }

    public static MultipartFileSender fromPath(Path path) {
        return new MultipartFileSender().setFilepath(path);
    }
    
    public static MultipartFileSender fromFile(File file) {
        return new MultipartFileSender().setFilepath(file.toPath());
    }

    public static MultipartFileSender fromURIString(String uri) {
        return new MultipartFileSender().setFilepath(Paths.get(uri));
    }

    //** internal setter **//
    private MultipartFileSender setFilepath(Path filepath) {
        this.filepath = filepath;
        return this;
    }
    
    public MultipartFileSender with(HttpServletRequest httpRequest) {
        request = httpRequest;
        return this;
    }
    
    public MultipartFileSender with(HttpServletResponse httpResponse) {
        response = httpResponse;
        return this;
    }
    
    public void serveResource() throws Exception {
        if (response == null || request == null) {
            return;
        }

        if (!Files.exists(filepath)) {
            logger.error("File doesn't exist at URI : {}", filepath.toAbsolutePath().toString());
            response.sendError(HttpServletResponse.SC_NOT_FOUND);
            return;
        }

        Long length = Files.size(filepath);
        String fileName = filepath.getFileName().toString();
        FileTime lastModifiedObj = Files.getLastModifiedTime(filepath);

        if (StringUtils.isEmpty(fileName) || lastModifiedObj == null) {
            response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            return;
        }
        long lastModified = LocalDateTime.ofInstant(lastModifiedObj.toInstant(), ZoneId.of(ZoneOffset.systemDefault().getId())).toEpochSecond(ZoneOffset.UTC);
        String contentType = MimeTypeUtils.probeContentType(filepath);

        // Validate request headers for caching ---------------------------------------------------

        // If-None-Match header should contain "*" or ETag. If so, then return 304.
        String ifNoneMatch = request.getHeader("If-None-Match");
        if (ifNoneMatch != null && HttpUtils.matches(ifNoneMatch, fileName)) {
            response.setHeader("ETag", fileName); // Required in 304.
            response.sendError(HttpServletResponse.SC_NOT_MODIFIED);
            return;
        }

        // If-Modified-Since header should be greater than LastModified. If so, then return 304.
        // This header is ignored if any If-None-Match header is specified.
        long ifModifiedSince = request.getDateHeader("If-Modified-Since");
        if (ifNoneMatch == null && ifModifiedSince != -1 && ifModifiedSince + 1000 > lastModified) {
            response.setHeader("ETag", fileName); // Required in 304.
            response.sendError(HttpServletResponse.SC_NOT_MODIFIED);
            return;
        }

        // Validate request headers for resume ----------------------------------------------------

        // If-Match header should contain "*" or ETag. If not, then return 412.
        String ifMatch = request.getHeader("If-Match");
        if (ifMatch != null && !HttpUtils.matches(ifMatch, fileName)) {
            response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
            return;
        }

        // If-Unmodified-Since header should be greater than LastModified. If not, then return 412.
        long ifUnmodifiedSince = request.getDateHeader("If-Unmodified-Since");
        if (ifUnmodifiedSince != -1 && ifUnmodifiedSince + 1000 <= lastModified) {
            response.sendError(HttpServletResponse.SC_PRECONDITION_FAILED);
            return;
        }

        // Validate and process range -------------------------------------------------------------

        // Prepare some variables. The full Range represents the complete file.
        Range full = new Range(0, length - 1, length);
        List<Range> ranges = new ArrayList<>();

        // Validate and process Range and If-Range headers.
        String range = request.getHeader("Range");
        if (range != null) {

            // Range header should match format "bytes=n-n,n-n,n-n...". If not, then return 416.
            if (!range.matches("^bytes=\\d*-\\d*(,\\d*-\\d*)*$")) {
                response.setHeader("Content-Range", "bytes */" + length); // Required in 416.
                response.sendError(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);
                return;
            }

            String ifRange = request.getHeader("If-Range");
            if (ifRange != null && !ifRange.equals(fileName)) {
                try {
                    long ifRangeTime = request.getDateHeader("If-Range"); // Throws IAE if invalid.
                    if (ifRangeTime != -1) {
                        ranges.add(full);
                    }
                } catch (IllegalArgumentException ignore) {
                    ranges.add(full);
                }
            }

            // If any valid If-Range header, then process each part of byte range.
            if (ranges.isEmpty()) {
                for (String part : range.substring(6).split(",")) {
                    // Assuming a file with length of 100, the following examples returns bytes at:
                    // 50-80 (50 to 80), 40- (40 to length=100), -20 (length-20=80 to length=100).
                    long start = Range.sublong(part, 0, part.indexOf("-"));
                    long end = Range.sublong(part, part.indexOf("-") + 1, part.length());

                    if (start == -1) {
                        start = length - end;
                        end = length - 1;
                    } else if (end == -1 || end > length - 1) {
                        end = length - 1;
                    }

                    // Check if Range is syntactically valid. If not, then return 416.
                    if (start > end) {
                        response.setHeader("Content-Range", "bytes */" + length); // Required in 416.
                        response.sendError(HttpServletResponse.SC_REQUESTED_RANGE_NOT_SATISFIABLE);
                        return;
                    }

                    // Add range.                    
                    ranges.add(new Range(start, end, length));
                }
            }
        }

        // Prepare and initialize response --------------------------------------------------------

        // Get content type by file name and set content disposition.
        String disposition = "inline";

        // If content type is unknown, then set the default value.
        // For all content types, see: http://www.w3schools.com/media/media_mimeref.asp
        // To add new content types, add new mime-mapping entry in web.xml.
        if (contentType == null) {
            contentType = "application/octet-stream";
        } else if (!contentType.startsWith("image")) {
            // Else, expect for images, determine content disposition. If content type is supported by
            // the browser, then set to inline, else attachment which will pop a 'save as' dialogue.
            String accept = request.getHeader("Accept");
            disposition = accept != null && HttpUtils.accepts(accept, contentType) ? "inline" : "attachment";
        }
        logger.debug("Content-Type : {}", contentType);
        // Initialize response.
        response.reset();
        response.setBufferSize(DEFAULT_BUFFER_SIZE);
        response.setHeader("Content-Type", contentType);
        response.setHeader("Content-Disposition", disposition + ";filename=\"" + fileName + "\"");
        logger.debug("Content-Disposition : {}", disposition);
        response.setHeader("Accept-Ranges", "bytes");
        response.setHeader("ETag", fileName);
        response.setDateHeader("Last-Modified", lastModified);
        response.setDateHeader("Expires", System.currentTimeMillis() + DEFAULT_EXPIRE_TIME);

        // Send requested file (part(s)) to client ------------------------------------------------

        // Prepare streams.
        try (InputStream input = new BufferedInputStream(Files.newInputStream(filepath));
             OutputStream output = response.getOutputStream()) {

            if (ranges.isEmpty() || ranges.get(0) == full) {

                // Return full file.
                logger.info("Return full file");
                response.setContentType(contentType);
                response.setHeader("Content-Range", "bytes " + full.start + "-" + full.end + "/" + full.total);
                response.setHeader("Content-Length", String.valueOf(full.length));
                Range.copy(input, output, length, full.start, full.length);

            } else if (ranges.size() == 1) {

                // Return single part of file.
                Range r = ranges.get(0);
                logger.info("Return 1 part of file : from ({}) to ({})", r.start, r.end);
                response.setContentType(contentType);
                response.setHeader("Content-Range", "bytes " + r.start + "-" + r.end + "/" + r.total);
                response.setHeader("Content-Length", String.valueOf(r.length));
                response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT); // 206.

                // Copy single part range.
                Range.copy(input, output, length, r.start, r.length);

            } else {

                // Return multiple parts of file.
                response.setContentType("multipart/byteranges; boundary=" + MULTIPART_BOUNDARY);
                response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT); // 206.

                // Cast back to ServletOutputStream to get the easy println methods.
                ServletOutputStream sos = (ServletOutputStream) output;

                // Copy multi part range.
                for (Range r : ranges) {
                    logger.info("Return multi part of file : from ({}) to ({})", r.start, r.end);
                    // Add multipart boundary and header fields for every range.
                    sos.println();
                    sos.println("--" + MULTIPART_BOUNDARY);
                    sos.println("Content-Type: " + contentType);
                    sos.println("Content-Range: bytes " + r.start + "-" + r.end + "/" + r.total);

                    // Copy single part range of multi part range.
                    Range.copy(input, output, length, r.start, r.length);
                }

                // End with multipart boundary.
                sos.println();
                sos.println("--" + MULTIPART_BOUNDARY + "--");
            }
        }

    }

    private static class Range {
        long start;
        long end;
        long length;
        long total;

        /**
         * Construct a byte range.
         * @param start Start of the byte range.
         * @param end End of the byte range.
         * @param total Total length of the byte source.
         */
        public Range(long start, long end, long total) {
            this.start = start;
            this.end = end;
            this.length = end - start + 1;
            this.total = total;
        }

        public static long sublong(String value, int beginIndex, int endIndex) {
            String substring = value.substring(beginIndex, endIndex);
            return (substring.length() > 0) ? Long.parseLong(substring) : -1;
        }

        private static void copy(InputStream input, OutputStream output, long inputSize, long start, long length) throws IOException {
            byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
            int read;

            if (inputSize == length) {
                // Write full range.
                while ((read = input.read(buffer)) > 0) {
                    output.write(buffer, 0, read);
                    output.flush();
                }
            } else {
                input.skip(start);
                long toRead = length;

                while ((read = input.read(buffer)) > 0) {
                    if ((toRead -= read) > 0) {
                        output.write(buffer, 0, read);
                        output.flush();
                    } else {
                        output.write(buffer, 0, (int) toRead + read);
                        output.flush();
                        break;
                    }
                }
            }
        }
    }
    private static class HttpUtils {

        /**
         * Returns true if the given accept header accepts the given value.
         * @param acceptHeader The accept header.
         * @param toAccept The value to be accepted.
         * @return True if the given accept header accepts the given value.
         */
        public static boolean accepts(String acceptHeader, String toAccept) {
            String[] acceptValues = acceptHeader.split("\\s*(,|;)\\s*");
            Arrays.sort(acceptValues);

            return Arrays.binarySearch(acceptValues, toAccept) > -1
                    || Arrays.binarySearch(acceptValues, toAccept.replaceAll("/.*$", "/*")) > -1
                    || Arrays.binarySearch(acceptValues, "*/*") > -1;
        }

        /**
         * Returns true if the given match header matches the given value.
         * @param matchHeader The match header.
         * @param toMatch The value to be matched.
         * @return True if the given match header matches the given value.
         */
        public static boolean matches(String matchHeader, String toMatch) {
            String[] matchValues = matchHeader.split("\\s*,\\s*");
            Arrays.sort(matchValues);
            return Arrays.binarySearch(matchValues, toMatch) > -1
                    || Arrays.binarySearch(matchValues, "*") > -1;
        }
    }
}

I implement that to allow the HTTP Byte Range in a Spring Context.. and after all, that can work everywhere :D

I was inspirited by "http://datum-bits.blogspot.fr/2013/01/implementing-http-byte-range-requests_30.html" and also by the DefaultServlet implementation of Apache Tomcat (https://svn.apache.org/repos/asf/tomcat/trunk/java/org/apache/catalina/servlets/DefaultServlet.java).

I share it because a lots of people ask me to, so I share it with the community !

I will do some refactor, so, follow the evolution in https://github.com/davinkevin/Podcast-Server

Hi,

i used your code to download with resume, a file in a jsp link like this:

String fileToServe = "e:/tmp/BigFile.ISO";
MultipartFileSender.fromFile(new File(fileToServe)).with(request).with(response).serveResource();

I stopped the download at the middle of the file and i resume download again. But the downlod begins from the start.

could you tell me please what is missing to be able to resume download?
Thanks alot for your help.

Wow, this is exactly what I needed! I've been searching for hours why my videos wouldn't play, and this solved it. You will definitely get credits when my application launches. Thank you very much!

You can check out my site here: http://pixeldra.in/ It's currently written in PHP, but I'm porting it to Spring because I like Java :).

I'm trying to get this to work with a file on a remote server, i.e. to proxy a video file to run on iOS and get around Cross Domain issues. Do you know if this is going to be possible or would I need to download the whole file to the server before sending it!?

While upgrading our system I accidentally broke our video player which caused our users to need to download the entire video file. This worked perfectly with a few modifications for our system. Thank you very much, it only took about 2 hours to get it working with our implementation. My boss liked it a lot