xref: /external/nanohttpd/core/src/main/java/fi/iki/elonen/NanoHTTPD.java

package fi.iki.elonen;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Properties;
import java.util.StringTokenizer;
import java.util.TimeZone;

/**
 * A simple, tiny, nicely embeddable HTTP 1.0 (partially 1.1) server in Java
 * <p/>
 * <p/>
 * NanoHTTPD version 1.25, Copyright &copy; 2001,2005-2012 Jarno Elonen (elonen@iki.fi, http://iki.fi/elonen/) and Copyright &copy; 2010
 * Konstantinos Togias (info@ktogias.gr, http://ktogias.gr)
 * <p/>
 * <p/>
 * <b>Features + limitations: </b>
 * <ul>
 * <p/>
 * <li>Only one Java file</li>
 * <li>Java 1.1 compatible</li>
 * <li>Released as open source, Modified BSD licence</li>
 * <li>No fixed config files, logging, authorization etc. (Implement yourself if you need them.)</li>
 * <li>Supports parameter parsing of GET and POST methods (+ rudimentary PUT support in 1.25)</li>
 * <li>Supports both dynamic content and file serving</li>
 * <li>Supports file upload (since version 1.2, 2010)</li>
 * <li>Supports partial content (streaming)</li>
 * <li>Supports ETags</li>
 * <li>Never caches anything</li>
 * <li>Doesn't limit bandwidth, request time or simultaneous connections</li>
 * <li>Default code serves files and shows all HTTP parameters and headers</li>
 * <li>File server supports directory listing, index.html and index.htm</li>
 * <li>File server supports partial content (streaming)</li>
 * <li>File server supports ETags</li>
 * <li>File server does the 301 redirection trick for directories without '/'</li>
 * <li>File server supports simple skipping for files (continue download)</li>
 * <li>File server serves also very long files without memory overhead</li>
 * <li>Contains a built-in list of most common mime types</li>
 * <li>All header names are converted lowercase so they don't vary between browsers/clients</li>
 * <p/>
 * </ul>
 * <p/>
 * <p/>
 * <b>Ways to use: </b>
 * <ul>
 * <p/>
 * <li>Run as a standalone app, serves files and shows requests</li>
 * <li>Subclass serve() and embed to your own program</li>
 * <li>Call serveFile() from serve() with your own base directory</li>
 * <p/>
 * </ul>
 * <p/>
 * See the end of the source file for distribution license (Modified BSD licence)
 */
public abstract class NanoHTTPD {
    /**
     * Hashtable mapping (String)FILENAME_EXTENSION -> (String)MIME_TYPE
     */
    private static final Map<String, String> MIME_TYPES;
    static {
        Map<String, String> mime = new HashMap<String, String>();
        mime.put("css", "text/css");
        mime.put("htm", "text/html");
        mime.put("html", "text/html");
        mime.put("xml", "text/xml");
        mime.put("txt", "text/plain");
        mime.put("asc", "text/plain");
        mime.put("gif", "image/gif");
        mime.put("jpg", "image/jpeg");
        mime.put("jpeg", "image/jpeg");
        mime.put("png", "image/png");
        mime.put("mp3", "audio/mpeg");
        mime.put("m3u", "audio/mpeg-url");
        mime.put("mp4", "video/mp4");
        mime.put("ogv", "video/ogg");
        mime.put("flv", "video/x-flv");
        mime.put("mov", "video/quicktime");
        mime.put("swf", "application/x-shockwave-flash");
        mime.put("js", "application/javascript");
        mime.put("pdf", "application/pdf");
        mime.put("doc", "application/msword");
        mime.put("ogg", "application/x-ogg");
        mime.put("zip", "application/octet-stream");
        mime.put("exe", "application/octet-stream");
        mime.put("class", "application/octet-stream");
        MIME_TYPES = mime;
    }

    public enum METHOD {
        GET, PUT, POST, DELETE;

        public boolean equalsIgnoreCase(String method) {
            return toString().equalsIgnoreCase(method);
        }

        static METHOD lookup(String method) {
            for (METHOD m : METHOD.values()) {
                if (m.toString().equalsIgnoreCase(method)) {
                    return m;
                }
            }
            return null;
        }
    }

    /**
     * Common mime types for dynamic content
     */
    public static final String MIME_PLAINTEXT = "text/plain";
    public static final String MIME_HTML = "text/html";
    public static final String MIME_DEFAULT_BINARY = "application/octet-stream";

    private final File myRootDir;
    private final int myPort;
    private ServerSocket myServerSocket;
    private Thread myThread;

    /**
     * Constructs an HTTP server on given port.
     */
    public NanoHTTPD(int port, File wwwroot) {
        this.myPort = port;
        this.myRootDir = wwwroot;
    }

    /**
     * Starts the server
     * <p/>
     * Throws an IOException if the socket is already in use
     */
    public void start() throws IOException {
        this.myServerSocket = new ServerSocket(myPort);
        myThread = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    do {
                        new HTTPSession(myServerSocket.accept());
                    } while (true);
                } catch (IOException ignored) {
                }
            }
        });
        myThread.setDaemon(true);
        myThread.start();
    }

    /**
     * Stops the server.
     */
    public void stop() {
        try {
            myServerSocket.close();
            myThread.join();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    /**
     * Return the HTTP root directory for this server
     */
    public File getRootDir() {
        return myRootDir;
    }

    /**
     * Override this to customize the server.
     * <p/>
     * <p/>
     * (By default, this delegates to serveFile() and allows directory listing.)
     *
     * @param uri    Percent-decoded URI without parameters, for example "/index.cgi"
     * @param method "GET", "POST" etc.
     * @param parms  Parsed, percent decoded parameters from URI and, in case of POST, data.
     * @param header Header entries, percent decoded
     * @return HTTP response, see class Response for details
     */
    public abstract Response serve(String uri, METHOD method, Map<String, String> header, Map<String, String> parms, Map<String, String> files);

    /**
     * Handles one session, i.e. parses the HTTP request and returns the response.
     */
    private class HTTPSession implements Runnable {
        public HTTPSession(Socket s) {
            mySocket = s;
            Thread t = new Thread(this);
            t.setDaemon(true);
            t.start();
        }

        @Override
        public void run() {
            try {
                InputStream is = mySocket.getInputStream();
                if (is == null)
                    return;

                // Read the first 8192 bytes.
                // The full header should fit in here.
                // Apache's default header limit is 8KB.
                // Do NOT assume that a single read will get the entire header at once!
                final int bufsize = 8192;
                byte[] buf = new byte[bufsize];
                int splitbyte = 0;
                int rlen = 0;
                {
                    int read = is.read(buf, 0, bufsize);
                    while (read > 0) {
                        rlen += read;
                        splitbyte = findHeaderEnd(buf, rlen);
                        if (splitbyte > 0)
                            break;
                        read = is.read(buf, rlen, bufsize - rlen);
                    }
                }

                // Create a BufferedReader for parsing the header.
                ByteArrayInputStream hbis = new ByteArrayInputStream(buf, 0, rlen);
                BufferedReader hin = new BufferedReader(new InputStreamReader(hbis));
                Properties pre = new Properties();
                Map<String, String> parms = new HashMap<String, String>();
                Map<String, String> header = new HashMap<String, String>();
                Map<String, String> files = new HashMap<String, String>();

                // Decode the header into parms and header java properties
                decodeHeader(hin, pre, parms, header);
                String methodStr = pre.getProperty("method");
                METHOD method = METHOD.lookup(methodStr);
                String uri = pre.getProperty("uri");

                long size = 0x7FFFFFFFFFFFFFFFl;
                String contentLength = header.get("content-length");
                if (contentLength != null) {
                    try {
                        size = Integer.parseInt(contentLength);
                    } catch (NumberFormatException ex) {
                        ex.printStackTrace();
                    }
                }

                // Write the part of body already read to ByteArrayOutputStream f
                ByteArrayOutputStream f = new ByteArrayOutputStream();
                if (splitbyte < rlen)
                    f.write(buf, splitbyte, rlen - splitbyte);

                // While Firefox sends on the first read all the data fitting
                // our buffer, Chrome and Opera send only the headers even if
                // there is data for the body. We do some magic here to find
                // out whether we have already consumed part of body, if we
                // have reached the end of the data to be sent or we should
                // expect the first byte of the body at the next read.
                if (splitbyte < rlen)
                    size -= rlen - splitbyte + 1;
                else if (splitbyte == 0 || size == 0x7FFFFFFFFFFFFFFFl)
                    size = 0;

                // Now read all the body and write it to f
                buf = new byte[512];
                while (rlen >= 0 && size > 0) {
                    rlen = is.read(buf, 0, 512);
                    size -= rlen;
                    if (rlen > 0)
                        f.write(buf, 0, rlen);
                }

                // Get the raw body as a byte []
                byte[] fbuf = f.toByteArray();

                // Create a BufferedReader for easily reading it as string.
                ByteArrayInputStream bin = new ByteArrayInputStream(fbuf);
                BufferedReader in = new BufferedReader(new InputStreamReader(bin));

                // If the method is POST, there may be parameters
                // in data section, too, read it:
                if (METHOD.POST.equals(method)) {
                    String contentType = "";
                    String contentTypeHeader = header.get("content-type");
                    StringTokenizer st = new StringTokenizer(contentTypeHeader, "; ");
                    if (st.hasMoreTokens()) {
                        contentType = st.nextToken();
                    }

                    if ("multipart/form-data".equalsIgnoreCase(contentType)) {
                        // Handle multipart/form-data
                        if (!st.hasMoreTokens())
                            sendError(Response.HTTP_STATUS.BAD_REQUEST,
                                    "BAD REQUEST: Content type is multipart/form-data but boundary missing. Usage: GET /example/file.html");
                        String boundaryExp = st.nextToken();
                        st = new StringTokenizer(boundaryExp, "=");
                        if (st.countTokens() != 2)
                            sendError(Response.HTTP_STATUS.BAD_REQUEST,
                                    "BAD REQUEST: Content type is multipart/form-data but boundary syntax error. Usage: GET /example/file.html");
                        st.nextToken();
                        String boundary = st.nextToken();

                        decodeMultipartData(boundary, fbuf, in, parms, files);
                    } else {
                        // Handle application/x-www-form-urlencoded
                        String postLine = "";
                        char pbuf[] = new char[512];
                        int read = in.read(pbuf);
                        while (read >= 0 && !postLine.endsWith("\r\n")) {
                            postLine += String.valueOf(pbuf, 0, read);
                            read = in.read(pbuf);
                        }
                        postLine = postLine.trim();
                        decodeParms(postLine, parms);
                    }
                }

                if (METHOD.PUT.equals(method))
                    files.put("content", saveTmpFile(fbuf, 0, f.size()));

                // Ok, now do the serve()
                Response r = serve(uri, method, header, parms, files);
                if (r == null)
                    sendError(Response.HTTP_STATUS.INTERNAL_ERROR, "SERVER INTERNAL ERROR: Serve() returned a null response.");
                else
                    sendResponse(r.status, r.mimeType, r.header, r.data);

                in.close();
                is.close();
            } catch (IOException ioe) {
                try {
                    sendError(Response.HTTP_STATUS.INTERNAL_ERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
                } catch (Throwable ignored) {
                }
            } catch (InterruptedException ie) {
                // Thrown by sendError, ignore and exit the thread.
            }
        }

        /**
         * Decodes the sent headers and loads the data into java Properties' key - value pairs
         */
        private void decodeHeader(BufferedReader in, Properties pre, Map<String, String> parms, Map<String, String> header)
                throws InterruptedException {
            try {
                // Read the request line
                String inLine = in.readLine();
                if (inLine == null)
                    return;
                StringTokenizer st = new StringTokenizer(inLine);
                if (!st.hasMoreTokens())
                    sendError(Response.HTTP_STATUS.BAD_REQUEST, "BAD REQUEST: Syntax error. Usage: GET /example/file.html");

                pre.put("method", st.nextToken());

                if (!st.hasMoreTokens())
                    sendError(Response.HTTP_STATUS.BAD_REQUEST, "BAD REQUEST: Missing URI. Usage: GET /example/file.html");

                String uri = st.nextToken();

                // Decode parameters from the URI
                int qmi = uri.indexOf('?');
                if (qmi >= 0) {
                    decodeParms(uri.substring(qmi + 1), parms);
                    uri = decodePercent(uri.substring(0, qmi));
                } else
                    uri = decodePercent(uri);

                // If there's another token, it's protocol version,
                // followed by HTTP headers. Ignore version but parse headers.
                // NOTE: this now forces header names lowercase since they are
                // case insensitive and vary by client.
                if (st.hasMoreTokens()) {
                    String line = in.readLine();
                    while (line != null && line.trim().length() > 0) {
                        int p = line.indexOf(':');
                        if (p >= 0)
                            header.put(line.substring(0, p).trim().toLowerCase(), line.substring(p + 1).trim());
                        line = in.readLine();
                    }
                }

                pre.put("uri", uri);
            } catch (IOException ioe) {
                sendError(Response.HTTP_STATUS.INTERNAL_ERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
            }
        }

        /**
         * Decodes the Multipart Body data and put it into java Properties' key - value pairs.
         */
        private void decodeMultipartData(String boundary, byte[] fbuf, BufferedReader in, Map<String, String> parms,
                                         Map<String, String> files) throws InterruptedException {
            try {
                int[] bpositions = getBoundaryPositions(fbuf, boundary.getBytes());
                int boundarycount = 1;
                String mpline = in.readLine();
                while (mpline != null) {
                    if (!mpline.contains(boundary)) {
                        sendError(Response.HTTP_STATUS.BAD_REQUEST,
                                "BAD REQUEST: Content type is multipart/form-data but next chunk does not start with boundary. Usage: GET /example/file.html");
                    }
                    boundarycount++;
                    Map<String, String> item = new HashMap<String, String>();
                    mpline = in.readLine();
                    while (mpline != null && mpline.trim().length() > 0) {
                        int p = mpline.indexOf(':');
                        if (p != -1) {
                            item.put(mpline.substring(0, p).trim().toLowerCase(), mpline.substring(p + 1).trim());
                        }
                        mpline = in.readLine();
                    }
                    if (mpline != null) {
                        String contentDisposition = item.get("content-disposition");
                        if (contentDisposition == null) {
                            sendError(Response.HTTP_STATUS.BAD_REQUEST,
                                    "BAD REQUEST: Content type is multipart/form-data but no content-disposition info found. Usage: GET /example/file.html");
                        }
                        StringTokenizer st = new StringTokenizer(contentDisposition, "; ");
                        Map<String, String> disposition = new HashMap<String, String>();
                        while (st.hasMoreTokens()) {
                            String token = st.nextToken();
                            int p = token.indexOf('=');
                            if (p != -1) {
                                disposition.put(token.substring(0, p).trim().toLowerCase(), token.substring(p + 1).trim());
                            }
                        }
                        String pname = disposition.get("name");
                        pname = pname.substring(1, pname.length() - 1);

                        String value = "";
                        if (item.get("content-type") == null) {
                            while (mpline != null && !mpline.contains(boundary)) {
                                mpline = in.readLine();
                                if (mpline != null) {
                                    int d = mpline.indexOf(boundary);
                                    if (d == -1) {
                                        value += mpline;
                                    } else {
                                        value += mpline.substring(0, d - 2);
                                    }
                                }
                            }
                        } else {
                            if (boundarycount > bpositions.length) {
                                sendError(Response.HTTP_STATUS.INTERNAL_ERROR, "Error processing request");
                            }
                            int offset = stripMultipartHeaders(fbuf, bpositions[boundarycount - 2]);
                            String path = saveTmpFile(fbuf, offset, bpositions[boundarycount - 1] - offset - 4);
                            files.put(pname, path);
                            value = disposition.get("filename");
                            value = value.substring(1, value.length() - 1);
                            do {
                                mpline = in.readLine();
                            } while (mpline != null && !mpline.contains(boundary));
                        }
                        parms.put(pname, value);
                    }
                }
            } catch (IOException ioe) {
                sendError(Response.HTTP_STATUS.INTERNAL_ERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage());
            }
        }

        /**
         * Find byte index separating header from body. It must be the last byte of the first two sequential new lines.
         */
        private int findHeaderEnd(final byte[] buf, int rlen) {
            int splitbyte = 0;
            while (splitbyte + 3 < rlen) {
                if (buf[splitbyte] == '\r' && buf[splitbyte + 1] == '\n' && buf[splitbyte + 2] == '\r' && buf[splitbyte + 3] == '\n') {
                    return splitbyte + 4;
                }
                splitbyte++;
            }
            return 0;
        }

        /**
         * Find the byte positions where multipart boundaries start.
         */
        public int[] getBoundaryPositions(byte[] b, byte[] boundary) {
            int matchcount = 0;
            int matchbyte = -1;
            List<Integer> matchbytes = new ArrayList<Integer>();
            for (int i = 0; i < b.length; i++) {
                if (b[i] == boundary[matchcount]) {
                    if (matchcount == 0)
                        matchbyte = i;
                    matchcount++;
                    if (matchcount == boundary.length) {
                        matchbytes.add(matchbyte);
                        matchcount = 0;
                        matchbyte = -1;
                    }
                } else {
                    i -= matchcount;
                    matchcount = 0;
                    matchbyte = -1;
                }
            }
            int[] ret = new int[matchbytes.size()];
            for (int i = 0; i < ret.length; i++) {
                ret[i] = matchbytes.get(i);
            }
            return ret;
        }

        /**
         * Retrieves the content of a sent file and saves it to a temporary file. The full path to the saved file is returned.
         */
        private String saveTmpFile(byte[] b, int offset, int len) {
            String path = "";
            if (len > 0) {
                String tmpdir = System.getProperty("java.io.tmpdir");
                try {
                    File temp = File.createTempFile("NanoHTTPD", "", new File(tmpdir));
                    OutputStream fstream = new FileOutputStream(temp);
                    fstream.write(b, offset, len);
                    fstream.close();
                    path = temp.getAbsolutePath();
                } catch (Exception e) { // Catch exception if any
                    System.err.println("Error: " + e.getMessage());
                }
            }
            return path;
        }

        /**
         * It returns the offset separating multipart file headers from the file's data.
         */
        private int stripMultipartHeaders(byte[] b, int offset) {
            int i;
            for (i = offset; i < b.length; i++) {
                if (b[i] == '\r' && b[++i] == '\n' && b[++i] == '\r' && b[++i] == '\n') {
                    break;
                }
            }
            return i + 1;
        }

        /**
         * Decodes the percent encoding scheme. <br/>
         * For example: "an+example%20string" -> "an example string"
         */
        private String decodePercent(String str) throws InterruptedException {
            try {
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < str.length(); i++) {
                    char c = str.charAt(i);
                    switch (c) {
                        case '+':
                            sb.append(' ');
                            break;
                        case '%':
                            sb.append((char) Integer.parseInt(str.substring(i + 1, i + 3), 16));
                            i += 2;
                            break;
                        default:
                            sb.append(c);
                            break;
                    }
                }
                return sb.toString();
            } catch (Exception e) {
                sendError(Response.HTTP_STATUS.BAD_REQUEST, "BAD REQUEST: Bad percent-encoding.");
                return null;
            }
        }

        /**
         * Decodes parameters in percent-encoded URI-format ( e.g. "name=Jack%20Daniels&pass=Single%20Malt" ) and adds them to given
         * Properties. NOTE: this doesn't support multiple identical keys due to the simplicity of Properties -- if you need multiples, you
         * might want to replace the Properties with a Hashtable of Vectors or such.
         */
        private void decodeParms(String parms, Map<String, String> p) throws InterruptedException {
            if (parms == null)
                return;

            StringTokenizer st = new StringTokenizer(parms, "&");
            while (st.hasMoreTokens()) {
                String e = st.nextToken();
                int sep = e.indexOf('=');
                if (sep >= 0) {
                    p.put(decodePercent(e.substring(0, sep)).trim(), decodePercent(e.substring(sep + 1)));
                }
            }
        }

        /**
         * Returns an error message as a HTTP response and throws InterruptedException to stop further request processing.
         */
        private void sendError(Response.HTTP_STATUS status, String msg) throws InterruptedException {
            sendResponse(status, MIME_PLAINTEXT, null, new ByteArrayInputStream(msg.getBytes()));
            throw new InterruptedException();
        }

        /**
         * Sends given response to the socket.
         */
        private void sendResponse(Response.HTTP_STATUS status, String mime, Map<String, String> header, InputStream data) {
            SimpleDateFormat gmtFrmt = new SimpleDateFormat("E, d MMM yyyy HH:mm:ss 'GMT'", Locale.US);
            gmtFrmt.setTimeZone(TimeZone.getTimeZone("GMT"));

            try {
                if (status == null) {
                    throw new Error("sendResponse(): Status can't be null.");
                }
                OutputStream out = mySocket.getOutputStream();
                PrintWriter pw = new PrintWriter(out);
                pw.print("HTTP/1.0 " + status + " \r\n");

                if (mime != null) {
                    pw.print("Content-Type: " + mime + "\r\n");
                }

                if (header == null || header.get("Date") == null) {
                    pw.print("Date: " + gmtFrmt.format(new Date()) + "\r\n");
                }

                if (header != null) {
                    for (String key : header.keySet()) {
                        String value = header.get(key);
                        pw.print(key + ": " + value + "\r\n");
                    }
                }

                pw.print("\r\n");
                pw.flush();

                if (data != null) {
                    int pending = data.available(); // This is to support partial sends, see serveFile()
                    int BUFFER_SIZE = 16 * 1024;
                    byte[] buff = new byte[BUFFER_SIZE];
                    while (pending > 0) {
                        int read = data.read(buff, 0, ((pending > BUFFER_SIZE) ? BUFFER_SIZE : pending));
                        if (read <= 0) {
                            break;
                        }
                        out.write(buff, 0, read);
                        pending -= read;
                    }
                }
                out.flush();
                out.close();
                if (data != null)
                    data.close();
            } catch (IOException ioe) {
                // Couldn't write? No can do.
                try {
                    mySocket.close();
                } catch (Throwable ignored) {
                }
            }
        }

        private final Socket mySocket;
    }

    /**
     * HTTP response. Return one of these from serve().
     */
    public static class Response {
        /**
         * Some HTTP response status codes
         */
        public enum HTTP_STATUS {
            OK(200, "OK"),
            PARTIAL_CONTENT(206, "Partial Content"),
            RANGE_NOT_SATISFIABLE(416, "Requested Range Not Satisfiable"),
            REDIRECT(301, "Moved Permanently"),
            NOT_MODIFIED(304, "Not Modified"),
            FORBIDDEN(403, "Forbidden"),
            NOT_FOUND(404, "Not Found"),
            BAD_REQUEST(400, "Bad Request"),
            INTERNAL_ERROR(500, "Internal Server Error");

            HTTP_STATUS(int requestStatus, String descr) {
                this.requestStatus = requestStatus;
                this.descr = descr;
            }
            private int requestStatus;
            private String descr;

            public int getRequestStatus() { return this.requestStatus; }
            public String getDescription() { return ""+this.requestStatus+" "+descr; }
        }

        /**
         * Default constructor: response = HTTP_OK, mime = MIME_HTML and your supplied message
         */
        public Response(String msg) {
            this(Response.HTTP_STATUS.OK, MIME_HTML, msg);
        }

        /**
         * Basic constructor.
         */
        public Response(HTTP_STATUS status, String mimeType, InputStream data) {
            this.status = status;
            this.mimeType = mimeType;
            this.data = data;
        }

        /**
         * Convenience method that makes an InputStream out of given text.
         */
        public Response(HTTP_STATUS status, String mimeType, String txt) {
            this.status = status;
            this.mimeType = mimeType;
            try {
                this.data = new ByteArrayInputStream(txt.getBytes("UTF-8"));
            } catch (java.io.UnsupportedEncodingException uee) {
                uee.printStackTrace();
            }
        }

        /**
         * Adds given line to the header.
         */
        public void addHeader(String name, String value) {
            header.put(name, value);
        }

        /**
         * HTTP status code after processing, e.g. "200 OK", HTTP_OK
         */
        public HTTP_STATUS status;

        /**
         * MIME type of content, e.g. "text/html"
         */
        public String mimeType;

        /**
         * Data of the response, may be null.
         */
        public InputStream data;

        /**
         * Headers for the HTTP response. Use addHeader() to add lines.
         */
        public Map<String, String> header = new HashMap<String, String>();
    }

    /**
     * The distribution licence
     */
    private static final String LICENCE = "Copyright (C) 2001,2005-2011 by Jarno Elonen <elonen@iki.fi>\n"
            + "and Copyright (C) 2010 by Konstantinos Togias <info@ktogias.gr>\n" + "\n"
            + "Redistribution and use in source and binary forms, with or without\n"
            + "modification, are permitted provided that the following conditions\n" + "are met:\n" + "\n"
            + "Redistributions of source code must retain the above copyright notice,\n"
            + "this list of conditions and the following disclaimer. Redistributions in\n"
            + "binary form must reproduce the above copyright notice, this list of\n"
            + "conditions and the following disclaimer in the documentation and/or other\n"
            + "materials provided with the distribution. The name of the author may not\n"
            + "be used to endorse or promote products derived from this software without\n"
            + "specific prior written permission. \n"
            + " \n" + "THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR\n"
            + "IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES\n"
            + "OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.\n"
            + "IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,\n"
            + "INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT\n"
            + "NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,\n"
            + "DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY\n"
            + "THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT\n"
            + "(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE\n"
            + "OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.";

    /**
     * Starts as a standalone file server and waits for Enter.
     */
    public static void main(String[] args) {
        System.out.println("NanoHTTPD 1.25 (C) 2001,2005-2011 Jarno Elonen and (C) 2010 Konstantinos Togias\n"
                + "(Command line options: [-p port] [-d root-dir] [--licence])\n");

        // Defaults
        int port = 8080;
        File wwwroot = new File(".").getAbsoluteFile();

        // Show licence if requested
        for (int i = 0; i < args.length; ++i)
            if (args[i].equalsIgnoreCase("-p"))
                port = Integer.parseInt(args[i + 1]);
            else if (args[i].equalsIgnoreCase("-d"))
                wwwroot = new File(args[i + 1]).getAbsoluteFile();
            else if (args[i].toLowerCase().endsWith("licence")) {
                System.out.println(LICENCE + "\n");
                break;
            }

        NanoHTTPD server = new NanoHTTPD(port, wwwroot) {
            /**
             * URL-encodes everything between "/"-characters. Encodes spaces as '%20' instead of '+'.
             */
            private String encodeUri(String uri) {
                String newUri = "";
                StringTokenizer st = new StringTokenizer(uri, "/ ", true);
                while (st.hasMoreTokens()) {
                    String tok = st.nextToken();
                    if (tok.equals("/"))
                        newUri += "/";
                    else if (tok.equals(" "))
                        newUri += "%20";
                    else {
                        try {
                            newUri += URLEncoder.encode(tok, "UTF-8");
                        } catch (UnsupportedEncodingException ignored) {
                        }
                    }
                }
                return newUri;
            }

            /**
             * Serves file from homeDir and its' subdirectories (only). Uses only URI, ignores all headers and HTTP parameters.
             */
            public Response serveFile(String uri, Map<String, String> header, File homeDir) {
                Response res = null;

                // Make sure we won't die of an exception later
                if (!homeDir.isDirectory())
                    res = new Response(Response.HTTP_STATUS.INTERNAL_ERROR, MIME_PLAINTEXT, "INTERNAL ERRROR: serveFile(): given homeDir is not a directory.");

                if (res == null) {
                    // Remove URL arguments
                    uri = uri.trim().replace(File.separatorChar, '/');
                    if (uri.indexOf('?') >= 0)
                        uri = uri.substring(0, uri.indexOf('?'));

                    // Prohibit getting out of current directory
                    if (uri.startsWith("src/main") || uri.endsWith("src/main") || uri.contains("../"))
                        res = new Response(Response.HTTP_STATUS.FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Won't serve ../ for security reasons.");
                }

                File f = new File(homeDir, uri);
                if (res == null && !f.exists())
                    res = new Response(Response.HTTP_STATUS.NOT_FOUND, MIME_PLAINTEXT, "Error 404, file not found.");

                // List the directory, if necessary
                if (res == null && f.isDirectory()) {
                    // Browsers get confused without '/' after the
                    // directory, send a redirect.
                    if (!uri.endsWith("/")) {
                        uri += "/";
                        res = new Response(Response.HTTP_STATUS.REDIRECT, MIME_HTML, "<html><body>Redirected: <a href=\"" + uri + "\">" + uri
                                + "</a></body></html>");
                        res.addHeader("Location", uri);
                    }

                    if (res == null) {
                        // First try index.html and index.htm
                        if (new File(f, "index.html").exists())
                            f = new File(homeDir, uri + "/index.html");
                        else if (new File(f, "index.htm").exists())
                            f = new File(homeDir, uri + "/index.htm");
                            // No index file, list the directory if it is readable
                        else if (f.canRead()) {
                            String[] files = f.list();
                            String msg = "<html><body><h1>Directory " + uri + "</h1><br/>";

                            if (uri.length() > 1) {
                                String u = uri.substring(0, uri.length() - 1);
                                int slash = u.lastIndexOf('/');
                                if (slash >= 0 && slash < u.length())
                                    msg += "<b><a href=\"" + uri.substring(0, slash + 1) + "\">..</a></b><br/>";
                            }

                            if (files != null) {
                                for (int i = 0; i < files.length; ++i) {
                                    File curFile = new File(f, files[i]);
                                    boolean dir = curFile.isDirectory();
                                    if (dir) {
                                        msg += "<b>";
                                        files[i] += "/";
                                    }

                                    msg += "<a href=\"" + encodeUri(uri + files[i]) + "\">" + files[i] + "</a>";

                                    // Show file size
                                    if (curFile.isFile()) {
                                        long len = curFile.length();
                                        msg += " &nbsp;<font size=2>(";
                                        if (len < 1024)
                                            msg += len + " bytes";
                                        else if (len < 1024 * 1024)
                                            msg += len / 1024 + "." + (len % 1024 / 10 % 100) + " KB";
                                        else
                                            msg += len / (1024 * 1024) + "." + len % (1024 * 1024) / 10 % 100 + " MB";

                                        msg += ")</font>";
                                    }
                                    msg += "<br/>";
                                    if (dir)
                                        msg += "</b>";
                                }
                            }
                            msg += "</body></html>";
                            res = new Response(msg);
                        } else {
                            res = new Response(Response.HTTP_STATUS.FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: No directory listing.");
                        }
                    }
                }

                try {
                    if (res == null) {
                        // Get MIME type from file name extension, if possible
                        String mime = null;
                        int dot = f.getCanonicalPath().lastIndexOf('.');
                        if (dot >= 0)
                            mime = MIME_TYPES.get(f.getCanonicalPath().substring(dot + 1).toLowerCase());
                        if (mime == null)
                            mime = MIME_DEFAULT_BINARY;

                        // Calculate etag
                        String etag = Integer.toHexString((f.getAbsolutePath() + f.lastModified() + "" + f.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 = f.length();
                        if (range != null && startFrom >= 0) {
                            if (startFrom >= fileLen) {
                                res = new Response(Response.HTTP_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(f) {
                                    @Override
                                    public int available() throws IOException {
                                        return (int) dataLen;
                                    }
                                };
                                fis.skip(startFrom);

                                res = new Response(Response.HTTP_STATUS.PARTIAL_CONTENT, mime, fis);
                                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 = new Response(Response.HTTP_STATUS.NOT_MODIFIED, mime, "");
                            else {
                                res = new Response(Response.HTTP_STATUS.OK, mime, new FileInputStream(f));
                                res.addHeader("Content-Length", "" + fileLen);
                                res.addHeader("ETag", etag);
                            }
                        }
                    }
                } catch (IOException ioe) {
                    res = new Response(Response.HTTP_STATUS.FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Reading file failed.");
                }

                res.addHeader("Accept-Ranges", "bytes"); // Announce that the file server accepts partial content requestes
                return res;
            }

            public Response serve(String uri, METHOD method, Map<String, String> header, Map<String, String> parms, Map<String, String> files) {
                System.out.println(method + " '" + uri + "' ");

                Iterator<String> e = header.keySet().iterator();
                while (e.hasNext()) {
                    String value = e.next();
                    System.out.println("  HDR: '" + value + "' = '" + header.get(value) + "'");
                }
                e = parms.keySet().iterator();
                while (e.hasNext()) {
                    String value = e.next();
                    System.out.println("  PRM: '" + value + "' = '" + parms.get(value) + "'");
                }
                e = files.keySet().iterator();
                while (e.hasNext()) {
                    String value = e.next();
                    System.out.println("  UPLOADED: '" + value + "' = '" + files.get(value) + "'");
                }

                return serveFile(uri, header, getRootDir());
            }
        };

        try {
            server.start();
        } catch (IOException ioe) {
            System.err.println("Couldn't start server:\n" + ioe);
            System.exit(-1);
        }

        System.out.println("Now serving files in port " + port + " from \"" + wwwroot + "\"");
        System.out.println("Hit Enter to stop.\n");

        try {
            System.in.read();
        } catch (Throwable ignored) {
        }

        server.stop();
    }
}