Android作為HTTP服務器--NanoHTTPD源碼分析

 

NanoHTTPD源碼以及解釋

 

package com.jwzhangjie.shafa.market.remotesetup;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.RandomAccessFile;
import java.io.PushbackInputStream;
import java.io.UnsupportedEncodingException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.net.URLDecoder;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TimeZone;

/**
 * A simple, tiny, nicely embeddable HTTP server in Java
 * 

*

* NanoHTTPD *

 

Copyright (c) 2012-2013 by Paul S. Hawke, 2001,2005-2013 by Jarno Elonen, 2010 by Konstantinos Togias

 

*

*

* Features + limitations: *

• *

  *

• Only one Java file
• *
• Java 5 compatible
• *
• Released as open source, Modified BSD licence
• *
• No fixed config files, logging, authorization etc. (Implement yourself if you need them.)
• *
• Supports parameter parsing of GET and POST methods (+ rudimentary PUT support in 1.25)
• *
• Supports both dynamic content and file serving
• *
• Supports file upload (since version 1.2, 2010)
• *
• Supports partial content (streaming)
• *
• Supports ETags
• *
• Never caches anything
• *
• Doesn't limit bandwidth, request time or simultaneous connections
• *
• Default code serves files and shows all HTTP parameters and headers
• *
• File server supports directory listing, index.html and index.htm
• *
• File server supports partial content (streaming)
• *
• File server supports ETags
• *
• File server does the 301 redirection trick for directories without '/'
• *
• File server supports simple skipping for files (continue download)
• *
• File server serves also very long files without memory overhead
• *
• Contains a built-in list of most common mime types
• *
• All header names are converted lowercase so they don't vary between browsers/clients
• *

  *

*

*

* How to use: *

• *

  *

• Subclass and implement serve() and embed to your own program
• *

  *

*

* See the separate LICENSE.md file for the distribution license (Modified BSD licence) */ public abstract class NanoHTTPD { /** * Maximum time to wait on Socket.getInputStream().read() (in milliseconds) * This is required as the Keep-Alive HTTP connections would otherwise * block the socket reading thread forever (or as long the browser is open). */ public static final int SOCKET_READ_TIMEOUT = 5000; /** * Common mime type for dynamic content: plain text */ public static final String MIME_PLAINTEXT = text/plain; /** * Common mime type for dynamic content: html */ public static final String MIME_HTML = text/html; /** * Pseudo-Parameter to use to store the actual query string in the parameters map for later re-processing. */ private static final String QUERY_STRING_PARAMETER = NanoHttpd.QUERY_STRING; private final String hostname; private final int myPort; private ServerSocket myServerSocket; private Set openConnections = new HashSet(); private Thread myThread; /** * Pluggable strategy for asynchronously executing requests. */ private AsyncRunner asyncRunner; /** * Pluggable strategy for creating and cleaning up temporary files. */ private TempFileManagerFactory tempFileManagerFactory; /** * Constructs an HTTP server on given port. */ public NanoHTTPD(int port) { this(null, port); } /** * Constructs an HTTP server on given hostname and port. */ public NanoHTTPD(String hostname, int port) { this.hostname = hostname; this.myPort = port; setTempFileManagerFactory(new DefaultTempFileManagerFactory()); setAsyncRunner(new DefaultAsyncRunner()); } private static final void safeClose(Closeable closeable) { if (closeable != null) { try { closeable.close(); } catch (IOException e) { } } } private static final void safeClose(Socket closeable) { if (closeable != null) { try { closeable.close(); } catch (IOException e) { } } } private static final void safeClose(ServerSocket closeable) { if (closeable != null) { try { closeable.close(); } catch (IOException e) { } } } /** * Start the server. * * @throws IOException if the socket is in use. */ public void start() throws IOException { myServerSocket = new ServerSocket(); myServerSocket.bind((hostname != null) ? new InetSocketAddress(hostname, myPort) : new InetSocketAddress(myPort)); myThread = new Thread(new Runnable() { @Override public void run() { do { try { final Socket finalAccept = myServerSocket.accept(); registerConnection(finalAccept); finalAccept.setSoTimeout(SOCKET_READ_TIMEOUT); final InputStream inputStream = finalAccept.getInputStream(); asyncRunner.exec(new Runnable() { @Override public void run() { OutputStream outputStream = null; try { outputStream = finalAccept.getOutputStream(); TempFileManager tempFileManager = tempFileManagerFactory.create(); HTTPSession session = new HTTPSession(tempFileManager, inputStream, outputStream, finalAccept.getInetAddress()); while (!finalAccept.isClosed()) { session.execute(); } } catch (Exception e) { // When the socket is closed by the client, we throw our own SocketException // to break the keep alive loop above. if (!(e instanceof SocketException && NanoHttpd Shutdown.equals(e.getMessage()))) { e.printStackTrace(); } } finally { safeClose(outputStream); safeClose(inputStream); safeClose(finalAccept); unRegisterConnection(finalAccept); } } }); } catch (IOException e) { } } while (!myServerSocket.isClosed()); } }); myThread.setDaemon(true); myThread.setName(NanoHttpd Main Listener); myThread.start(); } /** * Stop the server. */ public void stop() { try { safeClose(myServerSocket); closeAllConnections(); myThread.join(); } catch (Exception e) { e.printStackTrace(); } } /** * Registers that a new connection has been set up. * * @param socket * the {@link Socket} for the connection. */ public synchronized void registerConnection(Socket socket) { openConnections.add(socket); } /** * Registers that a connection has been closed * * @param socket * the {@link Socket} for the connection. */ public synchronized void unRegisterConnection(Socket socket) { openConnections.remove(socket); } /** * Forcibly closes all connections that are open. */ public synchronized void closeAllConnections() { for (Socket socket : openConnections) { safeClose(socket); } } public final int getListeningPort() { return myServerSocket == null ? -1 : myServerSocket.getLocalPort(); } public final boolean wasStarted() { return myServerSocket != null && myThread != null; } public final boolean isAlive() { return wasStarted() && !myServerSocket.isClosed() && myThread.isAlive(); } /** * Override this to customize the server. *

*

* (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 headers Header entries, percent decoded * @return HTTP response, see class Response for details */ @Deprecated public Response serve(String uri, Method method, Map headers, Map parms, Map files) { return new Response(Response.Status.NOT_FOUND, MIME_PLAINTEXT, Not Found); } /** * Override this to customize the server. *

*

* (By default, this delegates to serveFile() and allows directory listing.) * * @param session The HTTP session * @return HTTP response, see class Response for details * 我們需要自己實現這個方法 */ public Response serve(IHTTPSession session) { Map files = new HashMap(); Method method = session.getMethod(); if (Method.PUT.equals(method) || Method.POST.equals(method)) { try { session.parseBody(files); } catch (IOException ioe) { return new Response(Response.Status.INTERNAL_ERROR, MIME_PLAINTEXT, SERVER INTERNAL ERROR: IOException: + ioe.getMessage()); } catch (ResponseException re) { return new Response(re.getStatus(), MIME_PLAINTEXT, re.getMessage()); } } Map parms = session.getParms(); parms.put(QUERY_STRING_PARAMETER, session.getQueryParameterString()); return serve(session.getUri(), method, session.getHeaders(), parms, files); } /** * Decode percent encoded String values. * * @param str the percent encoded String * @return expanded form of the input, for example foo%20bar becomes foo bar */ protected String decodePercent(String str) { String decoded = null; try { decoded = URLDecoder.decode(str, UTF8); } catch (UnsupportedEncodingException ignored) { } return decoded; } /** * Decode parameters from a URL, handing the case where a single parameter name might have been * supplied several times, by return lists of values. In general these lists will contain a single * element. * * @param parms original NanoHttpd parameters values, as passed to the serve() method. * @return a map of String (parameter name) to List (a list of the values supplied). */ protected Map> decodeParameters(Map parms) { return this.decodeParameters(parms.get(QUERY_STRING_PARAMETER)); } /** * Decode parameters from a URL, handing the case where a single parameter name might have been * supplied several times, by return lists of values. In general these lists will contain a single * element. * * @param queryString a query string pulled from the URL. * @return a map of String (parameter name) to List (a list of the values supplied). */ protected Map> decodeParameters(String queryString) { Map> parms = new HashMap>(); if (queryString != null) { StringTokenizer st = new StringTokenizer(queryString, &); while (st.hasMoreTokens()) { String e = st.nextToken(); int sep = e.indexOf('='); String propertyName = (sep >= 0) ? decodePercent(e.substring(0, sep)).trim() : decodePercent(e).trim(); if (!parms.containsKey(propertyName)) { parms.put(propertyName, new ArrayList()); } String propertyValue = (sep >= 0) ? decodePercent(e.substring(sep + 1)) : null; if (propertyValue != null) { parms.get(propertyName).add(propertyValue); } } } return parms; } // ------------------------------------------------------------------------------- // // // Threading Strategy. // // ------------------------------------------------------------------------------- // /** * Pluggable strategy for asynchronously executing requests. * * @param asyncRunner new strategy for handling threads. */ public void setAsyncRunner(AsyncRunner asyncRunner) { this.asyncRunner = asyncRunner; } // ------------------------------------------------------------------------------- // // // Temp file handling strategy. // // ------------------------------------------------------------------------------- // /** * Pluggable strategy for creating and cleaning up temporary files. * * @param tempFileManagerFactory new strategy for handling temp files. */ public void setTempFileManagerFactory(TempFileManagerFactory tempFileManagerFactory) { this.tempFileManagerFactory = tempFileManagerFactory; } /** * HTTP Request methods, with the ability to decode a String back to its enum value. */ public enum Method { GET, PUT, POST, DELETE, HEAD, OPTIONS; static Method lookup(String method) { for (Method m : Method.values()) { if (m.toString().equalsIgnoreCase(method)) { return m; } } return null; } } /** * Pluggable strategy for asynchronously executing requests. */ public interface AsyncRunner { void exec(Runnable code); } /** * Factory to create temp file managers. */ public interface TempFileManagerFactory { TempFileManager create(); } // ------------------------------------------------------------------------------- // /** * Temp file manager. *

*

Temp file managers are created 1-to-1 with incoming requests, to create and cleanup * temporary files created as a result of handling the request.

*/ public interface TempFileManager { TempFile createTempFile() throws Exception; void clear(); } /** * A temp file. *

*

Temp files are responsible for managing the actual temporary storage and cleaning * themselves up when no longer needed.

*/ public interface TempFile { OutputStream open() throws Exception; void delete() throws Exception; String getName(); } /** * Default threading strategy for NanoHttpd. *

*

By default, the server spawns a new Thread for every incoming request. These are set * to daemon status, and named according to the request number. The name is * useful when profiling the application.

*/ public static class DefaultAsyncRunner implements AsyncRunner { private long requestCount; @Override public void exec(Runnable code) { ++requestCount; Thread t = new Thread(code); t.setDaemon(true); t.setName(NanoHttpd Request Processor (# + requestCount + )); t.start(); } } /** * Default strategy for creating and cleaning up temporary files. *

*

 

This class stores its files in the standard location (that is, * wherever java.io.tmpdir points to). Files are added * to an internal list, and deleted when no longer needed (that is, * when clear() is invoked at the end of processing a * request).

 

*/ public static class DefaultTempFileManager implements TempFileManager { private final String tmpdir; private final List tempFiles; public DefaultTempFileManager() { tmpdir = System.getProperty(java.io.tmpdir); tempFiles = new ArrayList(); } @Override public TempFile createTempFile() throws Exception { DefaultTempFile tempFile = new DefaultTempFile(tmpdir); tempFiles.add(tempFile); return tempFile; } @Override public void clear() { for (TempFile file : tempFiles) { try { file.delete(); } catch (Exception ignored) { } } tempFiles.clear(); } } /** * Default strategy for creating and cleaning up temporary files. *

*

 

By default, files are created by File.createTempFile() in * the directory specified.

 

*/ public static class DefaultTempFile implements TempFile { private File file; private OutputStream fstream; public DefaultTempFile(String tempdir) throws IOException { file = File.createTempFile(NanoHTTPD-, , new File(tempdir)); fstream = new FileOutputStream(file); } @Override public OutputStream open() throws Exception { return fstream; } @Override public void delete() throws Exception { safeClose(fstream); file.delete(); } @Override public String getName() { return file.getAbsolutePath(); } } /** * HTTP response. Return one of these from serve(). */ public static class Response { /** * HTTP status code after processing, e.g. 200 OK, HTTP_OK */ private Status status; /** * MIME type of content, e.g. text/html */ private String mimeType; /** * Data of the response, may be null. */ private InputStream data; /** * Headers for the HTTP response. Use addHeader() to add lines. */ private Map header = new HashMap(); /** * The request method that spawned this response. */ private Method requestMethod; /** * Use chunkedTransfer */ private boolean chunkedTransfer; /** * Default constructor: response = HTTP_OK, mime = MIME_HTML and your supplied message */ public Response(String msg) { this(Status.OK, MIME_HTML, msg); } /** * Basic constructor. */ public Response(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(Status status, String mimeType, String txt) { this.status = status; this.mimeType = mimeType; try { this.data = txt != null ? new ByteArrayInputStream(txt.getBytes(UTF-8)) : null; } catch (java.io.UnsupportedEncodingException uee) { uee.printStackTrace(); } } /** * Adds given line to the header. */ public void addHeader(String name, String value) { header.put(name, value); } /** * Sends given response to the socket. */ private void send(OutputStream outputStream) { String mime = mimeType; 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.); } PrintWriter pw = new PrintWriter(outputStream); pw.print(HTTP/1.1 + status.getDescription() + ); if (mime != null) { pw.print(Content-Type: + mime + ); } if (header == null || header.get(Date) == null) { pw.print(Date: + gmtFrmt.format(new Date()) + ); } if (header != null) { for (String key : header.keySet()) { String value = header.get(key); pw.print(key + : + value + ); } } pw.print(Connection: keep-alive ); if (requestMethod != Method.HEAD && chunkedTransfer) { sendAsChunked(outputStream, pw); } else { sendAsFixedLength(outputStream, pw); } outputStream.flush(); safeClose(data); } catch (IOException ioe) { // Couldn't write? No can do. } } private void sendAsChunked(OutputStream outputStream, PrintWriter pw) throws IOException { pw.print(Transfer-Encoding: chunked ); pw.print( ); pw.flush(); int BUFFER_SIZE = 16 * 1024; byte[] CRLF = .getBytes(); byte[] buff = new byte[BUFFER_SIZE]; int read; while ((read = data.read(buff)) > 0) { outputStream.write(String.format(%x , read).getBytes()); outputStream.write(buff, 0, read); outputStream.write(CRLF); } outputStream.write(String.format(0 ).getBytes()); } private void sendAsFixedLength(OutputStream outputStream, PrintWriter pw) throws IOException { int pending = data != null ? data.available() : 0; // This is to support partial sends, see serveFile() pw.print(Content-Length: +pending+ ); pw.print( ); pw.flush(); if (requestMethod != Method.HEAD && data != null) { 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; } outputStream.write(buff, 0, read); pending -= read; } } } public Status getStatus() { return status; } public void setStatus(Status status) { this.status = status; } public String getMimeType() { return mimeType; } public void setMimeType(String mimeType) { this.mimeType = mimeType; } public InputStream getData() { return data; } public void setData(InputStream data) { this.data = data; } public Method getRequestMethod() { return requestMethod; } public void setRequestMethod(Method requestMethod) { this.requestMethod = requestMethod; } public void setChunkedTransfer(boolean chunkedTransfer) { this.chunkedTransfer = chunkedTransfer; } /** * Some HTTP response status codes */ public enum Status { OK(200, OK), CREATED(201, Created), ACCEPTED(202, Accepted), NO_CONTENT(204, No Content), PARTIAL_CONTENT(206, Partial Content), REDIRECT(301, Moved Permanently), NOT_MODIFIED(304, Not Modified), BAD_REQUEST(400, Bad Request), UNAUTHORIZED(401, Unauthorized), FORBIDDEN(403, Forbidden), NOT_FOUND(404, Not Found), METHOD_NOT_ALLOWED(405, Method Not Allowed), RANGE_NOT_SATISFIABLE(416, Requested Range Not Satisfiable), INTERNAL_ERROR(500, Internal Server Error); private final int requestStatus; private final String description; Status(int requestStatus, String description) { this.requestStatus = requestStatus; this.description = description; } public int getRequestStatus() { return this.requestStatus; } public String getDescription() { return + this.requestStatus + + description; } } } public static final class ResponseException extends Exception { private final Response.Status status; public ResponseException(Response.Status status, String message) { super(message); this.status = status; } public ResponseException(Response.Status status, String message, Exception e) { super(message, e); this.status = status; } public Response.Status getStatus() { return status; } } /** * Default strategy for creating and cleaning up temporary files. */ private class DefaultTempFileManagerFactory implements TempFileManagerFactory { @Override public TempFileManager create() { return new DefaultTempFileManager(); } } /** * Handles one session, i.e. parses the HTTP request and returns the response. */ public interface IHTTPSession { void execute() throws IOException; Map getParms(); Map getHeaders(); /** * @return the path part of the URL. */ String getUri(); String getQueryParameterString(); Method getMethod(); InputStream getInputStream(); CookieHandler getCookies(); /** * Adds the files in the request body to the files map. * @arg files - map to modify */ void parseBody(Map files) throws IOException, ResponseException; } protected class HTTPSession implements IHTTPSession { public static final int BUFSIZE = 8192; private final TempFileManager tempFileManager; private final OutputStream outputStream; private PushbackInputStream inputStream; private int splitbyte; private int rlen; private String uri; private Method method; private Map parms; private Map headers; private CookieHandler cookies; private String queryParameterString; public HTTPSession(TempFileManager tempFileManager, InputStream inputStream, OutputStream outputStream) { this.tempFileManager = tempFileManager; this.inputStream = new PushbackInputStream(inputStream, BUFSIZE); this.outputStream = outputStream; } public HTTPSession(TempFileManager tempFileManager, InputStream inputStream, OutputStream outputStream, InetAddress inetAddress) { this.tempFileManager = tempFileManager; this.inputStream = new PushbackInputStream(inputStream, BUFSIZE); this.outputStream = outputStream; String remoteIp = inetAddress.isLoopbackAddress() || inetAddress.isAnyLocalAddress() ? 127.0.0.1 : inetAddress.getHostAddress().toString(); headers = new HashMap(); headers.put(remote-addr, remoteIp); headers.put(http-client-ip, remoteIp); } @Override public void execute() throws IOException { try { /* 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! header的最大長度為8192bytes，所以這裡設置BUFSIZE為8192bytes */ byte[] buf = new byte[BUFSIZE]; splitbyte = 0; rlen = 0;//總共的長度 { int read = -1;//每次讀取的長度 try { read = inputStream.read(buf, 0, BUFSIZE); } catch (Exception e) { safeClose(inputStream); safeClose(outputStream); throw new SocketException(NanoHttpd Shutdown); } if (read == -1) { // socket was been closed safeClose(inputStream); safeClose(outputStream); throw new SocketException(NanoHttpd Shutdown); } while (read > 0) { rlen += read; splitbyte = findHeaderEnd(buf, rlen); if (splitbyte > 0)//如果返回0則說明沒有找到 break; read = inputStream.read(buf, rlen, BUFSIZE - rlen); } } //如果讀多了，則將多余的部分重新寫到流裡面 if (splitbyte < rlen) { inputStream.unread(buf, splitbyte, rlen - splitbyte); } parms = new HashMap(); if(null == headers) { headers = new HashMap(); } // Create a BufferedReader for parsing the header. BufferedReader hin = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(buf, 0, rlen))); // Decode the header into parms and header java properties Map pre = new HashMap(); decodeHeader(hin, pre, parms, headers); /** * 取出客戶端請求的方式：GET/POST */ method = Method.lookup(pre.get(method)); if (method == null) { throw new ResponseException(Response.Status.BAD_REQUEST, BAD REQUEST: Syntax error.); } //請求的連接 uri = pre.get(uri); cookies = new CookieHandler(headers); /* * Ok, now do the serve() * 解析 */ Response r = serve(this); if (r == null) { throw new ResponseException(Response.Status.INTERNAL_ERROR, SERVER INTERNAL ERROR: Serve() returned a null response.); } else { cookies.unloadQueue(r); //響應客戶端信息 r.setRequestMethod(method); r.send(outputStream); } } catch (SocketException e) { // throw it out to close socket object (finalAccept) throw e; } catch (SocketTimeoutException ste) { throw ste; } catch (IOException ioe) { Response r = new Response(Response.Status.INTERNAL_ERROR, MIME_PLAINTEXT, SERVER INTERNAL ERROR: IOException: + ioe.getMessage()); r.send(outputStream); safeClose(outputStream); } catch (ResponseException re) { Response r = new Response(re.getStatus(), MIME_PLAINTEXT, re.getMessage()); r.send(outputStream); safeClose(outputStream); } finally { tempFileManager.clear(); } } @Override public void parseBody(Map files) throws IOException, ResponseException { RandomAccessFile randomAccessFile = null; BufferedReader in = null; try { //創建臨時文件 randomAccessFile = getTmpBucket(); long size; if (headers.containsKey(content-length)) { size = Integer.parseInt(headers.get(content-length)); } else if (splitbyte < rlen) { size = rlen - splitbyte; } else { size = 0; } /* * Now read all the body and write it to f * 將流的內容寫到臨時文件中 */ byte[] buf = new byte[512]; while (rlen >= 0 && size > 0) { rlen = inputStream.read(buf, 0, (int)Math.min(size, 512)); size -= rlen; if (rlen > 0) { randomAccessFile.write(buf, 0, rlen); } } // Get the raw body as a byte [] ByteBuffer fbuf = randomAccessFile.getChannel().map(FileChannel.MapMode.READ_ONLY, 0, randomAccessFile.length()); randomAccessFile.seek(0);//重新定位到臨時文件的開始位置 // Create a BufferedReader for easily reading it as string. InputStream bin = new FileInputStream(randomAccessFile.getFD()); 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 = headers.get(content-type); StringTokenizer st = null; if (contentTypeHeader != null) { st = new StringTokenizer(contentTypeHeader, ,; ); if (st.hasMoreTokens()) { contentType = st.nextToken(); } } //表單提交，文件上傳類型 if (multipart/form-data.equalsIgnoreCase(contentType)) { // Handle multipart/form-data if (!st.hasMoreTokens()) { throw new ResponseException(Response.Status.BAD_REQUEST, BAD REQUEST: Content type is multipart/form-data but boundary missing. Usage: GET /example/file.html); } String boundaryStartString = boundary=; int boundaryContentStart = contentTypeHeader.indexOf(boundaryStartString) + boundaryStartString.length(); String boundary = contentTypeHeader.substring(boundaryContentStart, contentTypeHeader.length()); if (boundary.startsWith() && boundary.endsWith()) { boundary = boundary.substring(1, boundary.length() - 1); } //fbuf裡面包含body的內容 decodeMultipartData(boundary, fbuf, in, parms, files); } else { // Handle application/x-www-form-urlencoded String postLine = ; StringBuilder postLineBuffer = new StringBuilder(); char pbuf[] = new char[512]; int read = in.read(pbuf); while (read >= 0 && !postLine.endsWith( )) { postLine = String.valueOf(pbuf, 0, read); postLineBuffer.append(postLine); read = in.read(pbuf); } postLine = postLineBuffer.toString().trim(); decodeParms(postLine, parms); } } else if (Method.PUT.equals(method)) { String content = saveTmpFile(fbuf, 0, fbuf.limit()); files.put(content, content); } } finally { safeClose(randomAccessFile); safeClose(in); } } /** * Decodes the sent headers and loads the data into Key/value pairs */ private void decodeHeader(BufferedReader in, Map pre, Map parms, Map headers) throws ResponseException { try { // Read the request line GET / HTTP/1.1 String inLine = in.readLine(); if (inLine == null) { return; } //分隔inLine用  StringTokenizer st = new StringTokenizer(inLine); if (!st.hasMoreTokens()) { throw new ResponseException(Response.Status.BAD_REQUEST, BAD REQUEST: Syntax error. Usage: GET /example/file.html); } String method = st.nextToken(); pre.put(method, method); if (!st.hasMoreTokens()) { throw new ResponseException(Response.Status.BAD_REQUEST, BAD REQUEST: Missing URI. Usage: GET /example/file.html); } String uri = st.nextToken(); /* * Decode parameters from the URI * 以? 來判斷是否有參數 */ int qmi = uri.indexOf('?'); if (qmi >= 0) {//說明有參數，調用decodeParms將參數解析到parms中 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) headers.put(line.substring(0, p).trim().toLowerCase(Locale.US), line.substring(p + 1).trim()); line = in.readLine(); } } pre.put(uri, uri); } catch (IOException ioe) { throw new ResponseException(Response.Status.INTERNAL_ERROR, SERVER INTERNAL ERROR: IOException: + ioe.getMessage(), ioe); } } /** * Decodes the Multipart Body data and put it into Key/Value pairs. * @param boundary * @param fbuf * @param in * @param parms header頭裡面的參數 * @param files 支持多文件上傳功能 * @throws ResponseException */ private void decodeMultipartData(String boundary, ByteBuffer fbuf, BufferedReader in, Map parms, Map files) throws ResponseException { try { //根據boundary獲取分割線與內容的間隔位置 int[] bpositions = getBoundaryPositions(fbuf, boundary.getBytes()); int boundarycount = 2;//源碼為1，如果是上傳單個文件會有問題 String mpline = in.readLine(); while (mpline != null) { if (!mpline.contains(boundary)) { throw new ResponseException(Response.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 item = new HashMap(); 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(Locale.US), mpline.substring(p + 1).trim()); } mpline = in.readLine(); } if (mpline != null) { String contentDisposition = item.get(content-disposition); if (contentDisposition == null) { throw new ResponseException(Response.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 disposition = new HashMap(); while (st.hasMoreTokens()) { String token = st.nextToken(); int p = token.indexOf('='); if (p != -1) { disposition.put(token.substring(0, p).trim().toLowerCase(Locale.US), 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) { throw new ResponseException(Response.Status.INTERNAL_ERROR, Error processing request); } int offset = stripMultipartHeaders(fbuf, bpositions[boundarycount - 2]); //創建一個臨時文件，然後保存內容，這個函數我們也需要重寫setTempFileManagerFactory 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) { throw new ResponseException(Response.Status.INTERNAL_ERROR, SERVER INTERNAL ERROR: IOException: + ioe.getMessage(), ioe); } } /** * Find byte index separating header from body. It must be the last byte of the first two sequential new lines. * 找到head和body的分界點，兩個回車換行 */ private int findHeaderEnd(final byte[] buf, int rlen) { int splitbyte = 0; while (splitbyte + 3 < rlen) { if (buf[splitbyte] == ' ' && buf[splitbyte + 1] == ' ' && buf[splitbyte + 2] == ' ' && buf[splitbyte + 3] == ' ') { return splitbyte + 4; } splitbyte++; } return 0; } /** * Find the byte positions where multipart boundaries start. * @param b * @param boundary * @return */ private int[] getBoundaryPositions(ByteBuffer b, byte[] boundary) { int matchcount = 0; int matchbyte = -1; List matchbytes = new ArrayList(); for (int i = 0; i < b.limit(); i++) { if (b.get(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(ByteBuffer b, int offset, int len) { String path = ; if (len > 0) { FileOutputStream fileOutputStream = null; try { //這個地方的tempFileManager需要我們setTempFileManagerFactory TempFile tempFile = tempFileManager.createTempFile(); ByteBuffer src = b.duplicate(); fileOutputStream = new FileOutputStream(tempFile.getName()); FileChannel dest = fileOutputStream.getChannel(); src.position(offset).limit(offset + len); dest.write(src.slice()); path = tempFile.getName(); } catch (Exception e) { // Catch exception if any System.err.println(Error: + e.getMessage()); } finally { safeClose(fileOutputStream); } } return path; } private RandomAccessFile getTmpBucket() { try { TempFile tempFile = tempFileManager.createTempFile(); return new RandomAccessFile(tempFile.getName(), rw); } catch (Exception e) { System.err.println(Error: + e.getMessage()); } return null; } /** * It returns the offset separating multipart file headers from the file's data. */ private int stripMultipartHeaders(ByteBuffer b, int offset) { int i; for (i = offset; i < b.limit(); i++) { if (b.get(i) == ' ' && b.get(++i) == ' ' && b.get(++i) == ' ' && b.get(++i) == ' ') { break; } } return i + 1; } /** * Decodes parameters in percent-encoded URI-format ( e.g. name=Jack%20Daniels&pass=Single%20Malt ) and * adds them to given Map. NOTE: this doesn't support multiple identical keys due to the simplicity of Map. */ private void decodeParms(String parms, Map p) { if (parms == null) { queryParameterString = ; return; } queryParameterString = parms; //使用&來分隔參數 StringTokenizer st = new StringTokenizer(parms, &); while (st.hasMoreTokens()) { String e = st.nextToken(); int sep = e.indexOf('='); if (sep >= 0) { /* * 這裡使用decodePercent來解析，防止參數裡面帶有中文 * 比如“張傑”那麼浏覽器會寫成%E5%BC%A0%E6%9D%B0 */ p.put(decodePercent(e.substring(0, sep)).trim(), decodePercent(e.substring(sep + 1))); } else { p.put(decodePercent(e).trim(), ); } } } @Override public final Map getParms() { return parms; } public String getQueryParameterString() { return queryParameterString; } @Override public final Map getHeaders() { return headers; } @Override public final String getUri() { return uri; } @Override public final Method getMethod() { return method; } @Override public final InputStream getInputStream() { return inputStream; } @Override public CookieHandler getCookies() { return cookies; } } public static class Cookie { private String n, v, e; public Cookie(String name, String value, String expires) { n = name; v = value; e = expires; } public Cookie(String name, String value) { this(name, value, 30); } public Cookie(String name, String value, int numDays) { n = name; v = value; e = getHTTPTime(numDays); } public String getHTTPHeader() { String fmt = %s=%s; expires=%s; return String.format(fmt, n, v, e); } public static String getHTTPTime(int days) { Calendar calendar = Calendar.getInstance(); SimpleDateFormat dateFormat = new SimpleDateFormat(EEE, dd MMM yyyy HH:mm:ss z, Locale.US); dateFormat.setTimeZone(TimeZone.getTimeZone(GMT)); calendar.add(Calendar.DAY_OF_MONTH, days); return dateFormat.format(calendar.getTime()); } } /** * Provides rudimentary support for cookies. * Doesn't support 'path', 'secure' nor 'httpOnly'. * Feel free to improve it and/or add unsupported features. * * @author LordFokas */ public class CookieHandler implements Iterable { private HashMap cookies = new HashMap(); private ArrayList queue = new ArrayList(); public CookieHandler(Map httpHeaders) { String raw = httpHeaders.get(cookie); if (raw != null) { String[] tokens = raw.split(;); for (String token : tokens) { String[] data = token.trim().split(=); if (data.length == 2) { cookies.put(data[0], data[1]); } } } } @Override public Iterator iterator() { return cookies.keySet().iterator(); } /** * Read a cookie from the HTTP Headers. * * @param name The cookie's name. * @return The cookie's value if it exists, null otherwise. */ public String read(String name) { return cookies.get(name); } /** * Sets a cookie. * * @param name The cookie's name. * @param value The cookie's value. * @param expires How many days until the cookie expires. */ public void set(String name, String value, int expires) { queue.add(new Cookie(name, value, Cookie.getHTTPTime(expires))); } public void set(Cookie cookie) { queue.add(cookie); } /** * Set a cookie with an expiration date from a month ago, effectively deleting it on the client side. * * @param name The cookie name. */ public void delete(String name) { set(name, -delete-, -30); } /** * Internally used by the webserver to add all queued cookies into the Response's HTTP Headers. * * @param response The Response object to which headers the queued cookies will be added. */ public void unloadQueue(Response response) { for (Cookie cookie : queue) { response.addHeader(Set-Cookie, cookie.getHTTPHeader()); } } } }

 

NanoHTTPD流程

NanoHTTPD是一個抽象類，所以要繼承NanoHTTPD，然後調用start()，在start()方法裡面主要實現ServerSocket，然後等待客戶端的連接，當有客戶端連接的時候，myServerSocket.accept()獲取socket實例，然後實例化InputStream和OutputStream，然後傳遞給HTTPSession類，在其execute()方法中 進行解析HTTP的header和body。

header解析

header和body直接使用兩個回車換行符來間隔，由於Header的最大長度為8k，所以創建了一個8k的緩沖，來讀取header，splitbyte = findHeaderEnd(buf, rlen);直到splitbyte 返回值大於0,說明已經知道分隔點，如果讀取的長度大於splitbyte ，則把多余的部分回寫到流裡面，然後創建一個BufferedReader來解析頭部數據調用decodeHeader方法

body解析

對於body的解析根據請求的方法分為PUT/POST，對於POST方法，使用serve方法來解析body，而serve這個方法也是我們實現NanoHTTPD類所要重寫的方法，parseBody來真正解析body，首先創建一個臨時文件把流裡面的數據寫到這個臨時文件中，然後實例化ByteBuffer和BufferedReader，如果提交表單的類型是multipart/form-data，查詢boundary，而boundary=就是內容數據的分割點，使用decodeMultipartData方法分離參數和內容數據，最後調用saveTmpFile方法來保存文件，為了保存到我們的本地文件中，所以我們還需要TempFileManagerFactory和TempFileManager，TempFileManager用來創建一個本地文件，用來存儲真正的上傳數據。

歡迎訪問個人開發論壇：http://jwzhangjie.com

專注盒子開發

@jwzhangjie