gistfile1.txt

package com.asus.robot.storytelling.chromecast;

import android.text.TextUtils;
import android.util.Log;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;

import fi.iki.elonen.NanoHTTPD;

/**
 * Created by semoncat on 2016/11/28.
 */
public class FileServer extends NanoHTTPD {

    private static final String TAG = "FileServer";

    public FileServer() {
        super(9527);
    }

    @Override
    public Response serve(IHTTPSession session) {

        String filePath = session.getParms().get("file_path");

        //filePath = "/storage/emulated/0/storytelling/TW_SevenSheep/interactive/videos/En_036.mp4";

        Log.d(TAG, "serve: " + filePath);

        if (!TextUtils.isEmpty(filePath)) {

            return serveFile(session.getHeaders(), new File(filePath));

        }

        return newChunkedResponse(Response.Status.BAD_REQUEST, "", null);
    }

    private Response serveFile(Map<String, String> header, File file) {
        Response res;
        String mime = "video/mp4";
        try {
            // Calculate etag
            String etag = Integer.toHexString((file.getAbsolutePath() +
                    file.lastModified() + "" + file.length()).hashCode());

            // Support (simple) skipping:
            long startFrom = 0;
            long endAt = -1;
            String range = header.get("range");
            if (range != null) {
                if (range.startsWith("bytes=")) {
                    range = range.substring("bytes=".length());
                    int minus = range.indexOf('-');
                    try {
                        if (minus > 0) {
                            startFrom = Long.parseLong(range.substring(0, minus));
                            endAt = Long.parseLong(range.substring(minus + 1));
                        }
                    } catch (NumberFormatException ignored) {
                    }
                }
            }

            // Change return code and add Content-Range header when skipping is requested
            long fileLen = file.length();
            if (range != null && startFrom >= 0) {
                if (startFrom >= fileLen) {
                    res = createResponse(Response.Status.RANGE_NOT_SATISFIABLE, MIME_PLAINTEXT, "");
                    res.addHeader("Content-Range", "bytes 0-0/" + fileLen);
                    res.addHeader("ETag", etag);
                } else {
                    if (endAt < 0) {
                        endAt = fileLen - 1;
                    }
                    long newLen = endAt - startFrom + 1;
                    if (newLen < 0) {
                        newLen = 0;
                    }

                    final long dataLen = newLen;
                    FileInputStream fis = new FileInputStream(file) {
                        @Override
                        public int available() throws IOException {
                            return (int) dataLen;
                        }
                    };
                    fis.skip(startFrom);

                    res = createResponse(Response.Status.PARTIAL_CONTENT, mime, fis, fis.available());
                    res.addHeader("Content-Length", "" + dataLen);
                    res.addHeader("Content-Range", "bytes " + startFrom + "-" +
                            endAt + "/" + fileLen);
                    res.addHeader("ETag", etag);
                }
            } else {
                if (etag.equals(header.get("if-none-match")))
                    res = createResponse(Response.Status.NOT_MODIFIED, mime, "");
                else {
                    res = createResponse(Response.Status.OK, mime, new FileInputStream(file), file.length());
                    res.addHeader("Content-Length", "" + fileLen);
                    res.addHeader("ETag", etag);
                }
            }
        } catch (IOException ioe) {
            res = getResponse("Forbidden: Reading file failed");
        }

        return (res == null) ? getResponse("Error 404: File not found") : res;
    }

    // Announce that the file server accepts partial content requests
    private Response createResponse(Response.Status status, String mimeType, InputStream message, long total) {
        Response res = newFixedLengthResponse(status, mimeType, message, total);
        res.addHeader("Accept-Ranges", "bytes");
        return res;
    }

    // Announce that the file server accepts partial content requests
    private Response createResponse(Response.Status status, String mimeType, String message) {
        Response res = newFixedLengthResponse(status, mimeType, message);
        res.addHeader("Accept-Ranges", "bytes");
        return res;
    }

    private Response getResponse(String message) {
        return createResponse(Response.Status.OK, "text/plain", message);
    }
}