Java tutorial
/* "Copyright (C) 2001,2005 by Jarno Elonen <elonen@iki.fi>\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."; */ import java.io.BufferedReader; import java.io.ByteArrayInputStream; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.PrintWriter; import java.net.ServerSocket; import java.net.Socket; import java.net.URLEncoder; import java.util.Date; import java.util.Enumeration; import java.util.Hashtable; import java.util.Locale; import java.util.Properties; import java.util.StringTokenizer; import java.util.TimeZone; /** * A simple, tiny, nicely embeddable HTTP 1.0 server in Java * * <p> * NanoHTTPD version 1.1, Copyright © 2001,2005-2007 Jarno Elonen * (elonen@iki.fi, http://iki.fi/elonen/) * * <p> * <b>Features + limitations: </b> * <ul> * * <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 </li> * <li> Supports both dynamic content and file serving </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 does the 301 redirection trick for directories without '/'</li> * <li> File server supports simple skipping for files (continue download) </li> * <li> File server uses current directory as a web root </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> * * </ul> * * <p> * <b>Ways to use: </b> * <ul> * * <li> Run as a standalone app, serves files from current directory 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> * * </ul> * * See the end of the source file for distribution license (Modified BSD * licence) */ public class NanoHTTPD { // // API parts // /** * Override this to customize the server. * <p> * * (By default, this delegates to serveFile() and allows directory listing.) * * @parm uri Percent-decoded URI without parameters, for example "/index.cgi" * @parm method "GET", "POST" etc. * @parm parms Parsed, percent decoded parameters from URI and, in case of * POST, data. * @parm header Header entries, percent decoded * @return HTTP response, see class Response for details */ public Response serve(String uri, String method, Properties header, Properties parms) { System.out.println(method + " '" + uri + "' "); Enumeration e = header.propertyNames(); while (e.hasMoreElements()) { String value = (String) e.nextElement(); System.out.println(" HDR: '" + value + "' = '" + header.getProperty(value) + "'"); } e = parms.propertyNames(); while (e.hasMoreElements()) { String value = (String) e.nextElement(); System.out.println(" PRM: '" + value + "' = '" + parms.getProperty(value) + "'"); } return serveFile(uri, header, new File("."), true); } /** * HTTP response. Return one of these from serve(). */ public class Response { /** * Default constructor: response = HTTP_OK, data = mime = 'null' */ public Response() { this.status = HTTP_OK; } /** * Basic constructor. */ public Response(String 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(String status, String mimeType, String txt) { this.status = status; this.mimeType = mimeType; this.data = new ByteArrayInputStream(txt.getBytes()); } /** * 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 String 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 Properties header = new Properties(); } /** * Some HTTP response status codes */ public static final String HTTP_OK = "200 OK", HTTP_REDIRECT = "301 Moved Permanently", HTTP_FORBIDDEN = "403 Forbidden", HTTP_NOTFOUND = "404 Not Found", HTTP_BADREQUEST = "400 Bad Request", HTTP_INTERNALERROR = "500 Internal Server Error", HTTP_NOTIMPLEMENTED = "501 Not Implemented"; /** * Common mime types for dynamic content */ public static final String MIME_PLAINTEXT = "text/plain", MIME_HTML = "text/html", MIME_DEFAULT_BINARY = "application/octet-stream"; // // Socket & server code // /** * Starts a HTTP server to given port. * <p> * Throws an IOException if the socket is already in use */ public NanoHTTPD(int port) throws IOException { myTcpPort = port; final ServerSocket ss = new ServerSocket(myTcpPort); Thread t = new Thread(new Runnable() { public void run() { try { while (true) new HTTPSession(ss.accept()); } catch (IOException ioe) { } } }); t.setDaemon(true); t.start(); } /** * Starts as a standalone file server and waits for Enter. */ public static void main(String[] args) { System.out.println( "NanoHTTPD 1.1 (C) 2001,2005-2007 Jarno Elonen\n" + "(Command line options: [port] [--licence])\n"); // Show licence if requested int lopt = -1; for (int i = 0; i < args.length; ++i) if (args[i].toLowerCase().endsWith("licence")) { lopt = i; System.out.println(LICENCE + "\n"); } // Change port if requested int port = 80; if (args.length > 0 && lopt != 0) port = Integer.parseInt(args[0]); if (args.length > 1 && args[1].toLowerCase().endsWith("licence")) System.out.println(LICENCE + "\n"); NanoHTTPD nh = null; try { nh = new NanoHTTPD(port); } catch (IOException ioe) { System.err.println("Couldn't start server:\n" + ioe); System.exit(-1); } nh.myFileDir = new File(""); System.out .println("Now serving files in port " + port + " from \"" + new File("").getAbsolutePath() + "\""); System.out.println("Hit Enter to stop.\n"); try { System.in.read(); } catch (Throwable t) { } ; } /** * 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(); } public void run() { try { InputStream is = mySocket.getInputStream(); if (is == null) return; BufferedReader in = new BufferedReader(new InputStreamReader(is)); // Read the request line StringTokenizer st = new StringTokenizer(in.readLine()); if (!st.hasMoreTokens()) sendError(HTTP_BADREQUEST, "BAD REQUEST: Syntax error. Usage: GET /example/file.html"); String method = st.nextToken(); if (!st.hasMoreTokens()) sendError(HTTP_BADREQUEST, "BAD REQUEST: Missing URI. Usage: GET /example/file.html"); String uri = decodePercent(st.nextToken()); // Decode parameters from the URI Properties parms = new Properties(); int qmi = uri.indexOf('?'); if (qmi >= 0) { decodeParms(uri.substring(qmi + 1), parms); uri = decodePercent(uri.substring(0, qmi)); } // If there's another token, it's protocol version, // followed by HTTP headers. Ignore version but parse headers. // NOTE: this now forces header names uppercase since they are // case insensitive and vary by client. Properties header = new Properties(); if (st.hasMoreTokens()) { String line = in.readLine(); while (line.trim().length() > 0) { int p = line.indexOf(':'); header.put(line.substring(0, p).trim().toLowerCase(), line.substring(p + 1).trim()); line = in.readLine(); } } // If the method is POST, there may be parameters // in data section, too, read it: if (method.equalsIgnoreCase("POST")) { long size = 0x7FFFFFFFFFFFFFFFl; String contentLength = header.getProperty("content-length"); if (contentLength != null) { try { size = Integer.parseInt(contentLength); } catch (NumberFormatException ex) { } } String postLine = ""; char buf[] = new char[512]; int read = in.read(buf); while (read >= 0 && size > 0 && !postLine.endsWith("\r\n")) { size -= read; postLine += String.valueOf(buf, 0, read); if (size > 0) read = in.read(buf); } postLine = postLine.trim(); decodeParms(postLine, parms); } // Ok, now do the serve() Response r = serve(uri, method, header, parms); if (r == null) sendError(HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: Serve() returned a null response."); else sendResponse(r.status, r.mimeType, r.header, r.data); in.close(); } catch (IOException ioe) { try { sendError(HTTP_INTERNALERROR, "SERVER INTERNAL ERROR: IOException: " + ioe.getMessage()); } catch (Throwable t) { } } catch (InterruptedException ie) { // Thrown by sendError, ignore and exit the thread. } } /** * Decodes the percent encoding scheme. <br/> For example: * "an+example%20string" -> "an example string" */ private String decodePercent(String str) throws InterruptedException { try { StringBuffer sb = new StringBuffer(); 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 new String(sb.toString().getBytes()); } catch (Exception e) { sendError(HTTP_BADREQUEST, "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. */ private void decodeParms(String parms, Properties 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 furhter request processing. */ private void sendError(String 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(String status, String mime, Properties header, InputStream data) { 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.getProperty("Date") == null) pw.print("Date: " + gmtFrmt.format(new Date()) + "\r\n"); if (header != null) { Enumeration e = header.keys(); while (e.hasMoreElements()) { String key = (String) e.nextElement(); String value = header.getProperty(key); pw.print(key + ": " + value + "\r\n"); } } pw.print("\r\n"); pw.flush(); if (data != null) { byte[] buff = new byte[2048]; while (true) { int read = data.read(buff, 0, 2048); if (read <= 0) break; out.write(buff, 0, read); } } out.flush(); out.close(); if (data != null) data.close(); } catch (IOException ioe) { // Couldn't write? No can do. try { mySocket.close(); } catch (Throwable t) { } } } private Socket mySocket; }; /** * 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 { newUri += URLEncoder.encode(tok); // For Java 1.4 you'll want to use this instead: // try { newUri += URLEncoder.encode( tok, "UTF-8" ); } catch ( // UnsupportedEncodingException uee ) } } return newUri; } private int myTcpPort; File myFileDir; // // File server code // /** * Serves file from homeDir and its' subdirectories (only). Uses only URI, * ignores all headers and HTTP parameters. */ public Response serveFile(String uri, Properties header, File homeDir, boolean allowDirectoryListing) { // Make sure we won't die of an exception later if (!homeDir.isDirectory()) return new Response(HTTP_INTERNALERROR, MIME_PLAINTEXT, "INTERNAL ERRROR: serveFile(): given homeDir is not a directory."); // 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("..") || uri.endsWith("..") || uri.indexOf("../") >= 0) return new Response(HTTP_FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Won't serve ../ for security reasons."); File f = new File(homeDir, uri); if (!f.exists()) return new Response(HTTP_NOTFOUND, MIME_PLAINTEXT, "Error 404, file not found."); // List the directory, if necessary if (f.isDirectory()) { // Browsers get confused without '/' after the // directory, send a redirect. if (!uri.endsWith("/")) { uri += "/"; Response r = new Response(HTTP_REDIRECT, MIME_HTML, "<html><body>Redirected: <a href=\"" + uri + "\">" + uri + "</a></body></html>"); r.addHeader("Location", uri); return r; } // 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 else if (allowDirectoryListing) { 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/>"; } 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 += " <font size=2>("; if (len < 1024) msg += curFile.length() + " bytes"; else if (len < 1024 * 1024) msg += curFile.length() / 1024 + "." + (curFile.length() % 1024 / 10 % 100) + " KB"; else msg += curFile.length() / (1024 * 1024) + "." + curFile.length() % (1024 * 1024) / 10 % 100 + " MB"; msg += ")</font>"; } msg += "<br/>"; if (dir) msg += "</b>"; } return new Response(HTTP_OK, MIME_HTML, msg); } else { return new Response(HTTP_FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: No directory listing."); } } try { // Get MIME type from file name extension, if possible String mime = null; int dot = f.getCanonicalPath().lastIndexOf('.'); if (dot >= 0) mime = (String) theMimeTypes.get(f.getCanonicalPath().substring(dot + 1).toLowerCase()); if (mime == null) mime = MIME_DEFAULT_BINARY; // Support (simple) skipping: long startFrom = 0; String range = header.getProperty("Range"); if (range != null) { if (range.startsWith("bytes=")) { range = range.substring("bytes=".length()); int minus = range.indexOf('-'); if (minus > 0) range = range.substring(0, minus); try { startFrom = Long.parseLong(range); } catch (NumberFormatException nfe) { } } } FileInputStream fis = new FileInputStream(f); fis.skip(startFrom); Response r = new Response(HTTP_OK, mime, fis); r.addHeader("Content-length", "" + (f.length() - startFrom)); r.addHeader("Content-range", "" + startFrom + "-" + (f.length() - 1) + "/" + f.length()); return r; } catch (IOException ioe) { return new Response(HTTP_FORBIDDEN, MIME_PLAINTEXT, "FORBIDDEN: Reading file failed."); } } /** * Hashtable mapping (String)FILENAME_EXTENSION -> (String)MIME_TYPE */ private static Hashtable theMimeTypes = new Hashtable(); static { StringTokenizer st = new StringTokenizer("htm text/html " + "html text/html " + "txt text/plain " + "asc text/plain " + "gif image/gif " + "jpg image/jpeg " + "jpeg image/jpeg " + "png image/png " + "mp3 audio/mpeg " + "m3u audio/mpeg-url " + "pdf application/pdf " + "doc application/msword " + "ogg application/x-ogg " + "zip application/octet-stream " + "exe application/octet-stream " + "class application/octet-stream "); while (st.hasMoreTokens()) theMimeTypes.put(st.nextToken(), st.nextToken()); } /** * GMT date formatter */ private static java.text.SimpleDateFormat gmtFrmt; static { gmtFrmt = new java.text.SimpleDateFormat("E, d MMM yyyy HH:mm:ss 'GMT'", Locale.US); gmtFrmt.setTimeZone(TimeZone.getTimeZone("GMT")); } /** * The distribution licence */ private static final String LICENCE = "Copyright (C) 2001,2005 by Jarno Elonen <elonen@iki.fi>\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."; }