Java tutorial
package fi.iki.elonen; /* * #%L * NanoHttpd-Webserver * %% * Copyright (C) 2012 - 2015 nanohttpd * %% * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * 3. Neither the name of the nanohttpd nor the names of its contributors * may be used to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * #L% */ import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FilenameFilter; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import java.net.InetAddress; import java.net.URLEncoder; import java.net.UnknownHostException; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.ServiceLoader; import java.util.StringTokenizer; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.util.Streams; import fi.iki.elonen.NanoHTTPD.Response.IStatus; import fi.iki.elonen.NanoHTTPD.Response.Status; import fi.iki.elonen.util.ServerRunner; public class SimpleWebServer extends NanoHTTPD { // For file upload public Map<String, List<FileItem>> files; private String serverIPAddr; private NanoFileUpload uploader; /** * Default Index file names. */ @SuppressWarnings("serial") public static final List<String> INDEX_FILE_NAMES = new ArrayList<String>() { { add("index.html"); add("index.htm"); } }; /** * The distribution licence */ private static final String LICENCE; static { mimeTypes(); String text; try { InputStream stream = SimpleWebServer.class.getResourceAsStream("/LICENSE.txt"); ByteArrayOutputStream bytes = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int count; while ((count = stream.read(buffer)) >= 0) { bytes.write(buffer, 0, count); } text = bytes.toString("UTF-8"); } catch (Exception e) { text = "unknown"; } LICENCE = text; } private static Map<String, WebServerPlugin> mimeTypeHandlers = new HashMap<String, WebServerPlugin>(); /** * Starts as a standalone file server and waits for Enter. */ public static void main(String[] args) { // Defaults int port = 8080; String host = null; // bind to all interfaces by default List<File> rootDirs = new ArrayList<File>(); boolean quiet = false; String cors = null; Map<String, String> options = new HashMap<String, String>(); // Parse command-line, with short and long versions of the options. for (int i = 0; i < args.length; ++i) { if ("-h".equalsIgnoreCase(args[i]) || "--host".equalsIgnoreCase(args[i])) { host = args[i + 1]; } else if ("-p".equalsIgnoreCase(args[i]) || "--port".equalsIgnoreCase(args[i])) { if (args[i + 1].equals("public")) { port = PUBLIC; } else if (args[i + 1].equals("private")) { port = PRIVATE; } else { port = Integer.parseInt(args[i + 1]); } } else if ("-q".equalsIgnoreCase(args[i]) || "--quiet".equalsIgnoreCase(args[i])) { quiet = true; } else if ("-d".equalsIgnoreCase(args[i]) || "--dir".equalsIgnoreCase(args[i])) { rootDirs.add(new File(args[i + 1]).getAbsoluteFile()); } else if (args[i].startsWith("--cors")) { cors = "*"; int equalIdx = args[i].indexOf('='); if (equalIdx > 0) { cors = args[i].substring(equalIdx + 1); } } else if ("--licence".equalsIgnoreCase(args[i])) { System.out.println(SimpleWebServer.LICENCE + "\n"); } else if (args[i].startsWith("-X:")) { int dot = args[i].indexOf('='); if (dot > 0) { String name = args[i].substring(0, dot); String value = args[i].substring(dot + 1, args[i].length()); options.put(name, value); } } } if (rootDirs.isEmpty()) { rootDirs.add(new File(".").getAbsoluteFile()); } options.put("host", host); options.put("port", "" + port); options.put("quiet", String.valueOf(quiet)); StringBuilder sb = new StringBuilder(); for (File dir : rootDirs) { if (sb.length() > 0) { sb.append(":"); } try { sb.append(dir.getCanonicalPath()); } catch (IOException ignored) { } } options.put("home", sb.toString()); ServiceLoader<WebServerPluginInfo> serviceLoader = ServiceLoader.load(WebServerPluginInfo.class); for (WebServerPluginInfo info : serviceLoader) { String[] mimeTypes = info.getMimeTypes(); for (String mime : mimeTypes) { String[] indexFiles = info.getIndexFilesForMimeType(mime); if (!quiet) { System.out.print("# Found plugin for Mime type: \"" + mime + "\""); if (indexFiles != null) { System.out.print(" (serving index files: "); for (String indexFile : indexFiles) { System.out.print(indexFile + " "); } } System.out.println(")."); } registerPluginForMimeType(indexFiles, mime, info.getWebServerPlugin(mime), options); } } ServerRunner.executeInstance(new SimpleWebServer(host, port, rootDirs, quiet, cors)); } protected static void registerPluginForMimeType(String[] indexFiles, String mimeType, WebServerPlugin plugin, Map<String, String> commandLineOptions) { if (mimeType == null || plugin == null) { return; } if (indexFiles != null) { for (String filename : indexFiles) { int dot = filename.lastIndexOf('.'); if (dot >= 0) { String extension = filename.substring(dot + 1).toLowerCase(); mimeTypes().put(extension, mimeType); } } SimpleWebServer.INDEX_FILE_NAMES.addAll(Arrays.asList(indexFiles)); } SimpleWebServer.mimeTypeHandlers.put(mimeType, plugin); plugin.initialize(commandLineOptions); } private final boolean quiet; private final String cors; protected List<File> rootDirs; public SimpleWebServer(String host, int port, File wwwroot, boolean quiet, String cors) { this(host, port, Collections.singletonList(wwwroot), quiet, cors); } public SimpleWebServer(String host, int port, File wwwroot, boolean quiet) { this(host, port, Collections.singletonList(wwwroot), quiet, null); } public SimpleWebServer(String host, int port, List<File> wwwroots, boolean quiet) { this(host, port, wwwroots, quiet, null); } public SimpleWebServer(String host, int port, List<File> wwwroots, boolean quiet, String cors) { super(host, port); this.quiet = quiet; this.cors = cors; this.rootDirs = new ArrayList<File>(wwwroots); try { this.serverIPAddr = (InetAddress.getLocalHost()).getHostAddress(); } catch (UnknownHostException e) { e.printStackTrace(); } init(); } private boolean canServeUri(String uri, File homeDir) { boolean canServeUri; File f = new File(homeDir, uri); canServeUri = f.exists(); if (!canServeUri) { WebServerPlugin plugin = SimpleWebServer.mimeTypeHandlers.get(getMimeTypeForFile(uri)); if (plugin != null) { canServeUri = plugin.canServeUri(uri, homeDir); } } return canServeUri; } /** * 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 ("/".equals(tok)) { newUri += "/"; } else if (" ".equals(tok)) { newUri += "%20"; } else { try { newUri += URLEncoder.encode(tok, "UTF-8"); } catch (UnsupportedEncodingException ignored) { } } } return newUri; } private String findIndexFileInDirectory(File directory) { for (String fileName : SimpleWebServer.INDEX_FILE_NAMES) { File indexFile = new File(directory, fileName); if (indexFile.isFile()) { return fileName; } } return null; } protected Response getForbiddenResponse(String s) { return newFixedLengthResponse(Response.Status.FORBIDDEN, NanoHTTPD.MIME_PLAINTEXT, "FORBIDDEN: " + s); } protected Response getInternalErrorResponse(String s) { return newFixedLengthResponse(Response.Status.INTERNAL_ERROR, NanoHTTPD.MIME_PLAINTEXT, "INTERNAL ERROR: " + s); } protected Response getNotFoundResponse() { return newFixedLengthResponse(Response.Status.NOT_FOUND, NanoHTTPD.MIME_PLAINTEXT, "Error 404, file not found."); } /** * Used to initialize and customize the server. */ public void init() { } protected String listDirectory(String uri, File f) { String heading = "Directory " + uri; StringBuilder msg = new StringBuilder("<html><head><title>" + heading + "</title><style><!--\n" + "span.dirname { font-weight: bold; }\n" + "span.filesize { font-size: 75%; }\n" + "// -->\n" + "</style>" + "</head><body><h1>" + heading + "</h1>"); String up = null; if (uri.length() > 1) { String u = uri.substring(0, uri.length() - 1); int slash = u.lastIndexOf('/'); if (slash >= 0 && slash < u.length()) { up = uri.substring(0, slash + 1); } } List<String> files = Arrays.asList(f.list(new FilenameFilter() { @Override public boolean accept(File dir, String name) { return new File(dir, name).isFile(); } })); Collections.sort(files); List<String> directories = Arrays.asList(f.list(new FilenameFilter() { @Override public boolean accept(File dir, String name) { return new File(dir, name).isDirectory(); } })); Collections.sort(directories); if (up != null || directories.size() + files.size() > 0) { msg.append("<ul>"); if (up != null || directories.size() > 0) { msg.append("<section class=\"directories\">"); if (up != null) { msg.append("<li><a rel=\"directory\" href=\"").append(up) .append("\"><span class=\"dirname\">..</span></a></b></li>"); } for (String directory : directories) { String dir = directory + "/"; msg.append("<li><a rel=\"directory\" href=\"").append(encodeUri(uri + dir)) .append("\"><span class=\"dirname\">").append(dir).append("</span></a></b></li>"); } msg.append("</section>"); } if (files.size() > 0) { msg.append("<section class=\"files\">"); for (String file : files) { msg.append("<li><a href=\"").append(encodeUri(uri + file)) .append("\"><span class=\"filename\">").append(file).append("</span></a>"); File curFile = new File(f, file); long len = curFile.length(); msg.append(" <span class=\"filesize\">("); if (len < 1024) { msg.append(len).append(" bytes"); } else if (len < 1024 * 1024) { msg.append(len / 1024).append(".").append(len % 1024 / 10 % 100).append(" KB"); } else { msg.append(len / (1024 * 1024)).append(".").append(len % (1024 * 1024) / 10000 % 100) .append(" MB"); } msg.append(")</span></li>"); } msg.append("</section>"); } msg.append("</ul>"); } msg.append("</body></html>"); return msg.toString(); } public static Response newFixedLengthResponse(IStatus status, String mimeType, String message) { Response response = NanoHTTPD.newFixedLengthResponse(status, mimeType, message); response.addHeader("Accept-Ranges", "bytes"); return response; } private Response respond(Map<String, String> headers, IHTTPSession session, String uri) { // First let's handle CORS OPTION query Response r; if (cors != null && Method.OPTIONS.equals(session.getMethod())) { r = new NanoHTTPD.Response(Response.Status.OK, MIME_PLAINTEXT, null, 0); } else { r = defaultRespond(headers, session, uri); } if (cors != null) { r = addCORSHeaders(headers, r, cors); } return r; } private Response defaultRespond(Map<String, String> headers, IHTTPSession session, String uri) { // 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.contains("../")) { return getForbiddenResponse("Won't serve ../ for security reasons."); } boolean canServeUri = false; File homeDir = null; for (int i = 0; !canServeUri && i < this.rootDirs.size(); i++) { homeDir = this.rootDirs.get(i); canServeUri = canServeUri(uri, homeDir); } if (!canServeUri) { return getNotFoundResponse(); } // Browsers get confused without '/' after the directory, send a // redirect. File f = new File(homeDir, uri); if (f.isDirectory() && !uri.endsWith("/")) { uri += "/"; Response res = newFixedLengthResponse(Response.Status.REDIRECT, NanoHTTPD.MIME_HTML, "<html><body>Redirected: <a href=\"" + uri + "\">" + uri + "</a></body></html>"); res.addHeader("Location", uri); return res; } if (f.isDirectory()) { // First look for index files (index.html, index.htm, etc) and if // none found, list the directory if readable. String indexFile = findIndexFileInDirectory(f); if (indexFile == null) { if (f.canRead()) { // No index file, list the directory if it is readable return newFixedLengthResponse(Response.Status.OK, NanoHTTPD.MIME_HTML, listDirectory(uri, f)); } else { return getForbiddenResponse("No directory listing."); } } else { return respond(headers, session, uri + indexFile); } } String mimeTypeForFile = getMimeTypeForFile(uri); WebServerPlugin plugin = SimpleWebServer.mimeTypeHandlers.get(mimeTypeForFile); Response response = null; if (plugin != null && plugin.canServeUri(uri, homeDir)) { response = plugin.serveFile(uri, headers, session, f, mimeTypeForFile); if (response != null && response instanceof InternalRewrite) { InternalRewrite rewrite = (InternalRewrite) response; return respond(rewrite.getHeaders(), session, rewrite.getUri()); } } else { response = serveFile(uri, headers, f, mimeTypeForFile); } return response != null ? response : getNotFoundResponse(); } @Override public Response serve(IHTTPSession session) { Response response = newFixedLengthResponse(""); Map<String, String> header = session.getHeaders(); Map<String, String> parms = session.getParms(); String uri = session.getUri(); if (!this.quiet) { System.out.println(session.getMethod() + " '" + 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) + "'"); // If the client send stop message, exit the program if (value.compareTo("exit") == 0 && (parms.get(value)).compareTo("true") == 0) { remoteCloseProgram(); } } } for (File homeDir : this.rootDirs) { // Make sure we won't die of an exception later if (!homeDir.isDirectory()) { return getInternalErrorResponse("given path is not a directory (" + homeDir + ")."); } } // Handle file uploading if ("/uploadpage".equals(uri)) { return getUploadformPage(); } // Store the file uploaded from client if (NanoFileUpload.isMultipartContent(session)) { try { if ("/uploadFile".equals(uri)) { return getUploadMsgAndExec(session); } } catch (Exception e) { response.setStatus(Status.INTERNAL_ERROR); e.printStackTrace(); } } response = respond(Collections.unmodifiableMap(header), session, uri); return response; } /** * Serves file from homeDir and its' subdirectories (only). Uses only URI, * ignores all headers and HTTP parameters. */ Response serveFile(String uri, Map<String, String> header, File file, String mime) { Response res; 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) { } } } // get if-range header. If present, it must match etag or else we // should ignore the range request String ifRange = header.get("if-range"); boolean headerIfRangeMissingOrMatching = (ifRange == null || etag.equals(ifRange)); String ifNoneMatch = header.get("if-none-match"); boolean headerIfNoneMatchPresentAndMatching = ifNoneMatch != null && ("*".equals(ifNoneMatch) || ifNoneMatch.equals(etag)); // Change return code and add Content-Range header when skipping is // requested long fileLen = file.length(); if (headerIfRangeMissingOrMatching && range != null && startFrom >= 0 && startFrom < fileLen) { // range request that matches current etag // and the startFrom of the range is satisfiable if (headerIfNoneMatchPresentAndMatching) { // range request that matches current etag // and the startFrom of the range is satisfiable // would return range from file // respond with not-modified res = newFixedLengthResponse(Response.Status.NOT_MODIFIED, mime, ""); res.addHeader("ETag", etag); } else { if (endAt < 0) { endAt = fileLen - 1; } long newLen = endAt - startFrom + 1; if (newLen < 0) { newLen = 0; } FileInputStream fis = new FileInputStream(file); fis.skip(startFrom); res = newFixedLengthResponse(Response.Status.PARTIAL_CONTENT, mime, fis, newLen); res.addHeader("Accept-Ranges", "bytes"); res.addHeader("Content-Length", "" + newLen); res.addHeader("Content-Range", "bytes " + startFrom + "-" + endAt + "/" + fileLen); res.addHeader("ETag", etag); } } else { if (headerIfRangeMissingOrMatching && range != null && startFrom >= fileLen) { // return the size of the file // 4xx responses are not trumped by if-none-match res = newFixedLengthResponse(Response.Status.RANGE_NOT_SATISFIABLE, NanoHTTPD.MIME_PLAINTEXT, ""); res.addHeader("Content-Range", "bytes */" + fileLen); res.addHeader("ETag", etag); } else if (range == null && headerIfNoneMatchPresentAndMatching) { // full-file-fetch request // would return entire file // respond with not-modified res = newFixedLengthResponse(Response.Status.NOT_MODIFIED, mime, ""); res.addHeader("ETag", etag); } else if (!headerIfRangeMissingOrMatching && headerIfNoneMatchPresentAndMatching) { // range request that doesn't match current etag // would return entire (different) file // respond with not-modified res = newFixedLengthResponse(Response.Status.NOT_MODIFIED, mime, ""); res.addHeader("ETag", etag); } else { // supply the file res = newFixedFileResponse(file, mime); res.addHeader("Content-Length", "" + fileLen); res.addHeader("ETag", etag); } } } catch (IOException ioe) { res = getForbiddenResponse("Reading file failed."); } return res; } // Send the form-upload page to the client private Response getUploadformPage() { return newFixedLengthResponse("<html><body> \n <form action=\"http://" + serverIPAddr + ":" + (new Integer(this.getListeningPort())).toString() + "/uploadFile\" enctype=\"multipart/form-data\" method=\"post\" >\n" + " <input type=\"file\" id=\"datafile1\" name=\"datafile1\" " + "size=\"40\" ><br>\n <input type=\"submit\"> \n </form> \n " + "</body></html>\n"); } // Get the uploaded files from client and store in the server locally private Response getUploadMsgAndExec(IHTTPSession session) throws FileUploadException, IOException { uploader = new NanoFileUpload(new DiskFileItemFactory()); files = new HashMap<String, List<FileItem>>(); FileItemIterator iter = uploader.getItemIterator(session); String fileName = "", newFileName = ""; try { while (iter.hasNext()) { FileItemStream item = iter.next(); fileName = item.getName(); newFileName = rootDirs.get(0) + "/".concat(fileName); FileItem fileItem = uploader.getFileItemFactory().createItem(item.getFieldName(), item.getContentType(), item.isFormField(), newFileName); files.put(fileItem.getFieldName(), Arrays.asList(new FileItem[] { fileItem })); try { Streams.copy(item.openStream(), (new FileOutputStream(newFileName)), true); } catch (Exception e) { System.err.println(e.getMessage()); } fileItem.setHeaders(item.getHeaders()); } } catch (FileUploadException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } return newFixedLengthResponse( "<html><body> \n File: " + fileName + " upload to " + newFileName + "! \n </body></html>\n"); } private Response newFixedFileResponse(File file, String mime) throws FileNotFoundException { Response res; res = newFixedLengthResponse(Response.Status.OK, mime, new FileInputStream(file), (int) file.length()); res.addHeader("Accept-Ranges", "bytes"); return res; } protected Response addCORSHeaders(Map<String, String> queryHeaders, Response resp, String cors) { resp.addHeader("Access-Control-Allow-Origin", cors); resp.addHeader("Access-Control-Allow-Headers", calculateAllowHeaders(queryHeaders)); resp.addHeader("Access-Control-Allow-Credentials", "true"); resp.addHeader("Access-Control-Allow-Methods", ALLOWED_METHODS); resp.addHeader("Access-Control-Max-Age", "" + MAX_AGE); return resp; } private String calculateAllowHeaders(Map<String, String> queryHeaders) { // here we should use the given asked headers // but NanoHttpd uses a Map whereas it is possible for requester to send // several time the same header // let's just use default values for this version return System.getProperty(ACCESS_CONTROL_ALLOW_HEADER_PROPERTY_NAME, DEFAULT_ALLOWED_HEADERS); } private void remoteCloseProgram() { setIsEsc(true); } private final static int PUBLIC = 30801; private final static int PRIVATE = 31502; private final static String ALLOWED_METHODS = "GET, POST, PUT, DELETE, OPTIONS, HEAD"; private final static int MAX_AGE = 42 * 60 * 60; // explicitly relax visibility to package for tests purposes final static String DEFAULT_ALLOWED_HEADERS = "origin,accept,content-type"; public final static String ACCESS_CONTROL_ALLOW_HEADER_PROPERTY_NAME = "AccessControlAllowHeader"; }