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  • Java实现Http服务器(四)

    (1)HTTPServer的监听启动

    sun.net.httpserver.ServerImpl类中启动了Socket监听,ServerImpl的内部类Dispatch类启动了Http服务器的监听

     /* main server listener task */
    
        class Dispatcher implements Runnable {
    
            private void handleEvent (Event r) {
                ExchangeImpl t = r.exchange;
                HttpConnection c = t.getConnection();
                try {
                    if (r instanceof WriteFinishedEvent) {
    
                        int exchanges = endExchange();
                        if (terminating && exchanges == 0) {
                            finished = true;
                        }
                        SocketChannel chan = c.getChannel();
                        LeftOverInputStream is = t.getOriginalInputStream();
                        if (!is.isEOF()) {
                            t.close = true;
                        }
                        if (t.close || idleConnections.size() >= MAX_IDLE_CONNECTIONS) {
                            c.close();
                            allConnections.remove (c);
                        } else {
                            if (is.isDataBuffered()) {
                                /* don't re-enable the interestops, just handle it */
                                handle (c.getChannel(), c);
                            } else {
                                /* re-enable interestops */
                                SelectionKey key = c.getSelectionKey();
                                if (key.isValid()) {
                                    key.interestOps (
                                        key.interestOps()|SelectionKey.OP_READ
                                    );
                                }
                                c.time = getTime() + IDLE_INTERVAL;
                                idleConnections.add (c);
                            }
                        }
                    }
                } catch (IOException e) {
                    logger.log (
                        Level.FINER, "Dispatcher (1)", e
                    );
                    c.close();
                }
            }
    
            public void run() {
                while (!finished) {
                    try {
    
                        /* process the events list first */
    
                        while (resultSize() > 0) {
                            Event r;
                            synchronized (lolock) {
                                r = events.remove(0);
                                handleEvent (r);
                            }
                        }
    
                        selector.select(1000);
    
                        /* process the selected list now  */
    
                        Set<SelectionKey> selected = selector.selectedKeys();
                        Iterator<SelectionKey> iter = selected.iterator();
                        while (iter.hasNext()) {
                            SelectionKey key = iter.next();
                            iter.remove ();
                            if (key.equals (listenerKey)) {
                                if (terminating) {
                                    continue;
                                }
                                SocketChannel chan = schan.accept();
                                if (chan == null) {
                                    continue; /* cancel something ? */
                                }
                                chan.configureBlocking (false);
                                SelectionKey newkey = chan.register (selector, SelectionKey.OP_READ);
                                HttpConnection c = new HttpConnection ();
                                c.selectionKey = newkey;
                                c.setChannel (chan);
                                newkey.attach (c);
                                allConnections.add (c);
                            } else {
                                try {
                                    if (key.isReadable()) {
                                        boolean closed;
                                        SocketChannel chan = (SocketChannel)key.channel();
                                        HttpConnection conn = (HttpConnection)key.attachment();
                                        // interestOps will be restored at end of read
                                        key.interestOps (0);
                                        handle (chan, conn);
                                    } else {
                                        assert false;
                                    }
                                } catch (IOException e) {
                                    HttpConnection conn = (HttpConnection)key.attachment();
                                    logger.log (
                                        Level.FINER, "Dispatcher (2)", e
                                    );
                                    conn.close();
                                }
                            }
                        }
                    } catch (CancelledKeyException  e) {
                        logger.log (Level.FINER, "Dispatcher (3)", e);
                    } catch (IOException e) {
                        logger.log (Level.FINER, "Dispatcher (4)", e);
                    } catch (Exception e) {
                        logger.log (Level.FINER, "Dispatcher (7)", e);
                    }
                }
            }
    
            public void handle (SocketChannel chan, HttpConnection conn)
            throws IOException
            {
                try {
                    Exchange t = new Exchange (chan, protocol, conn);
                    executor.execute (t);
                } catch (HttpError e1) {
                    logger.log (Level.FINER, "Dispatcher (5)", e1);
                    conn.close();
                } catch (IOException e) {
                    logger.log (Level.FINER, "Dispatcher (6)", e);
                    conn.close();
                }
            }
        }
    
        static boolean debug = ServerConfig.debugEnabled ();
    
        static synchronized void dprint (String s) {
            if (debug) {
                System.out.println (s);
            }
        }
    
        static synchronized void dprint (Exception e) {
            if (debug) {
                System.out.println (e);
                e.printStackTrace();
            }
        }
    
        Logger getLogger () {
            return logger;
        }
    

     

    该类的初始化在sun.net.httpserver.ServerImpl的构造方法当中

    ServerImpl (HttpServer wrapper, String protocol, InetSocketAddress addr, int backlog) throws IOException {
            this.protocol = protocol;
            this.wrapper = wrapper;
            this.logger = Logger.getLogger ("com.sun.net.httpserver");
            https = protocol.equalsIgnoreCase ("https");
            this.address = addr;
            contexts = new ContextList();
            schan = ServerSocketChannel.open();
            if (addr != null) {
                ServerSocket socket = schan.socket();
                socket.bind (addr, backlog);
                bound = true;
            }
            selector = Selector.open ();
            schan.configureBlocking (false);
            listenerKey = schan.register (selector, SelectionKey.OP_ACCEPT);
            dispatcher = new Dispatcher();
            idleConnections = Collections.synchronizedSet (new HashSet<HttpConnection>());
            allConnections = Collections.synchronizedSet (new HashSet<HttpConnection>());
            time = System.currentTimeMillis();
            timer = new Timer ("server-timer", true);
            timer.schedule (new ServerTimerTask(), CLOCK_TICK, CLOCK_TICK);
            events = new LinkedList<Event>();
            logger.config ("HttpServer created "+protocol+" "+ addr);
        }
    

    随后在sun.net.httpserver.ServerImpl类的start方法当中,作为线程被启动

    public void start () {
            if (!bound || started || finished) {
                throw new IllegalStateException ("server in wrong state");
            }
            if (executor == null) {
                executor = new DefaultExecutor();
            }
            Thread t = new Thread (dispatcher);
            started = true;
            t.start();
        }
    
    import com.sun.net.httpserver.HttpServer;
    private HttpServer httpServer = null; public final void init() throws IOException { this.executor = Executors.newCachedThreadPool(); final InetSocketAddress sa = new InetSocketAddress("0.0.0.0", 8080); this.httpServer = HttpServer.create(sa, 0); this.httpServer.setExecutor(this.executor); this.httpServer.createContext("/", new HttpServerHandler()); this.httpServer.start(); }

    上面是使用JDK内置HttpServer的方法。

    在第二篇文章中介绍过返回的默认对象是

    sun.net.httpserver.HttpServerImpl对象,该对象是com.sun.net.httpserver.HttpServer对象的子类

    public class HttpServerImpl extends HttpServer {
    
        ServerImpl server;
    
        HttpServerImpl () throws IOException {
            this (new InetSocketAddress(80), 0);
        }
    
        HttpServerImpl (
            InetSocketAddress addr, int backlog
        ) throws IOException {
            server = new ServerImpl (this, "http", addr, backlog);
        }
    .............................................
    }

    该对象又是ServerImpl对象的外观类,提供了HttpServer的方法,封装了ServerImpl自身的各种方法实现

    最终在应用中调用this.httpserver.start()

    本质上调用的就是sun.net.httpserver.ServerImpl对象的start()方法

    ---------------------------------------------------------------------------------------------------------------------------------------

    下面分析下Dispatcher类中run方法的监听过程

    public void run() {
    //server的关闭标志,在调用httpserver.stop()方法后--->即ServerImpl类的stop()方法,设置finished为true(初始化为false) while (!finished) { try { /* process the events list first */ //由于支持HTTP1.1的原因,在一次发送数据结束之后,并不是立即关闭连接和socket,而是将发送完成作为一个事件传递过来,根据上下文决定是否关闭连接 while (resultSize() > 0) { Event r; synchronized (lolock) { r = events.remove(0); handleEvent (r); } } selector.select(1000); /* process the selected list now */ Set<SelectionKey> selected = selector.selectedKeys(); Iterator<SelectionKey> iter = selected.iterator(); while (iter.hasNext()) { SelectionKey key = iter.next(); iter.remove (); if (key.equals (listenerKey)) { if (terminating) { continue; } SocketChannel chan = schan.accept(); if (chan == null) { continue; /* cancel something ? */ } chan.configureBlocking (false); SelectionKey newkey = chan.register (selector, SelectionKey.OP_READ); HttpConnection c = new HttpConnection (); c.selectionKey = newkey; c.setChannel (chan); newkey.attach (c); allConnections.add (c); } else { try { if (key.isReadable()) { boolean closed; SocketChannel chan = (SocketChannel)key.channel(); HttpConnection conn = (HttpConnection)key.attachment(); // interestOps will be restored at end of read key.interestOps (0); handle (chan, conn); } else { assert false; } } catch (IOException e) { HttpConnection conn = (HttpConnection)key.attachment(); logger.log ( Level.FINER, "Dispatcher (2)", e ); conn.close(); } } } } catch (CancelledKeyException e) { logger.log (Level.FINER, "Dispatcher (3)", e); } catch (IOException e) { logger.log (Level.FINER, "Dispatcher (4)", e); } catch (Exception e) { logger.log (Level.FINER, "Dispatcher (7)", e); } } }

    设置请求处理器的方法

    public HttpContextImpl createContext (String path, HttpHandler handler) {
            return server.createContext (path, handler);
    }
    
    public synchronized HttpContextImpl createContext (String path) {
            if (path == null) {
                throw new NullPointerException ("null path parameter");
            }
            HttpContextImpl context = new HttpContextImpl (protocol, path, null, this);
            contexts.add (context);
            logger.config ("context created: " + path);
            return context;
    }
    

    HttpContextImpl类的介绍

    /**
    * HttpContext represents a mapping between a protocol (http or https) together with a root URI path
    * to a {@link HttpHandler} which is invoked to handle requests destined
    * for the protocol/path on the associated HttpServer.
    * <p>
    * HttpContext instances are created by {@link HttpServer#createContext(String,String,HttpHandler,Object)}
    * <p>
    */

    contexts对象是  private ContextList contexts; 

    是ServerImpl的成员变量

    该类提供了URL和处理该URL的Handler的映射,可以看到,最多支持50个URL的处理。

    add(HttpContextImpl ctx)方法增加映射对象

    findContext(String protocol,String path) 返回相应请求的HttpContextImpl对象 

    下面可以看一下find的过程(坚持最长匹配 比如/guowuxin/hello  /guowuxin 这是两个映射  则当/guowuxin 请求来的时候将使用前者的映射,貌似很没有礼貌)

    坚持最长匹配也是没有使用map的原因

    (1)判断protocol (HTTP1.0 HTTP1.1)

    (2)exact变量要求是否是全匹配亦或者是开头(startsWith) 默认 我们看到run方法中默认的是开头匹配

    package sun.net.httpserver;
    
    import java.util.*;
    import com.sun.net.httpserver.*;
    import com.sun.net.httpserver.spi.*;
    
    class ContextList {
    
        final static int MAX_CONTEXTS = 50;
    
        LinkedList<HttpContextImpl> list = new LinkedList<HttpContextImpl>();
    
        public synchronized void add (HttpContextImpl ctx) {
            assert ctx.getPath() != null;
            list.add (ctx);
        }
    
        public synchronized int size () {
            return list.size();
        }
    
       /* initially contexts are located only by protocol:path.
        * Context with longest prefix matches (currently case-sensitive)
        */
        synchronized HttpContextImpl findContext (String protocol, String path) {
            return findContext (protocol, path, false);
        }
    
        synchronized HttpContextImpl findContext (String protocol, String path, boolean exact) {
            protocol = protocol.toLowerCase();
            String longest = "";
            HttpContextImpl lc = null;
            for (HttpContextImpl ctx: list) {
                if (!ctx.getProtocol().equals(protocol)) {
                    continue;
                }
                String cpath = ctx.getPath();
                if (exact && !cpath.equals (path)) {
                    continue;
                } else if (!exact && !path.startsWith(cpath)) {
                    continue;
                }
                if (cpath.length() > longest.length()) {
                    longest = cpath;
                    lc = ctx;
                }
            }
            return lc;
        }
    
        public synchronized void remove (String protocol, String path)
            throws IllegalArgumentException
        {
            HttpContextImpl ctx = findContext (protocol, path, true);
            if (ctx == null) {
                throw new IllegalArgumentException ("cannot remove element from list");
            }
            list.remove (ctx);
        }
    
        public synchronized void remove (HttpContextImpl context)
            throws IllegalArgumentException
        {
            for (HttpContextImpl ctx: list) {
                if (ctx.equals (context)) {
                    list.remove (ctx);
                    return;
                }
            }
            throw new IllegalArgumentException ("no such context in list");
        }
    }
    

      

    -------------------------------------------------------------------------------------------------------------------------------------------------

    下面重点分析下server端的HttpConnection的复用(在HTTP1.1协议下,TCP连接在发送完数据之后不会断开)

     exchange.getResponseBody().close();

    这里就要先介绍下,我们的请求处理器HttpHandler接口

    package com.sun.net.httpserver;
    
    import java.io.IOException;
    
    /**
     * A handler which is invoked to process HTTP exchanges. Each
     * HTTP exchange is handled by one of these handlers.
     * @since 1.6
     */
    public interface HttpHandler {
        /**
         * Handle the given request and generate an appropriate response.
         * See {@link HttpExchange} for a description of the steps
         * involved in handling an exchange.
         * @param exchange the exchange containing the request from the
         *      client and used to send the response
         * @throws NullPointerException if exchange is <code>null</code>
         */
        public abstract void handle (HttpExchange exchange) throws IOException;
    }
    

    该接口的实现类用于处理相应的url请求,其中参数HttpExchange类如其名,作用就是接收输入参数,返回输出信息,就是用来交换Http消息的一个工具接口。

    下面是它的一个实现类,也是一个外观类,包装了ExchangeImpl类,提供了HttpExchange接口的方法,封装了ExchangeImpl类的方法。

    package sun.net.httpserver;
    
    import java.io.*;
    import java.nio.*;
    import java.nio.channels.*;
    import java.net.*;
    import javax.net.ssl.*;
    import java.util.*;
    import sun.net.www.MessageHeader;
    import com.sun.net.httpserver.*;
    import com.sun.net.httpserver.spi.*;
    
    class HttpExchangeImpl extends HttpExchange {
    
        ExchangeImpl impl;
    
        HttpExchangeImpl (ExchangeImpl impl) {
            this.impl = impl;
        }
    
        public Headers getRequestHeaders () {
            return impl.getRequestHeaders();
        }
    
        public Headers getResponseHeaders () {
            return impl.getResponseHeaders();
        }
    
        public URI getRequestURI () {
            return impl.getRequestURI();
        }
    
        public String getRequestMethod (){
            return impl.getRequestMethod();
        }
    
        public HttpContextImpl getHttpContext (){
            return impl.getHttpContext();
        }
    
        public void close () {
            impl.close();
        }
    
        public InputStream getRequestBody () {
            return impl.getRequestBody();
        }
    
        public int getResponseCode () {
            return impl.getResponseCode();
        }
    
        public OutputStream getResponseBody () {
            return impl.getResponseBody();
        }
    
    
        public void sendResponseHeaders (int rCode, long contentLen)
        throws IOException
        {
            impl.sendResponseHeaders (rCode, contentLen);
        }
    
        public InetSocketAddress getRemoteAddress (){
            return impl.getRemoteAddress();
        }
    
        public InetSocketAddress getLocalAddress (){
            return impl.getLocalAddress();
        }
    
        public String getProtocol (){
            return impl.getProtocol();
        }
    
        public Object getAttribute (String name) {
            return impl.getAttribute (name);
        }
    
        public void setAttribute (String name, Object value) {
            impl.setAttribute (name, value);
        }
    
        public void setStreams (InputStream i, OutputStream o) {
            impl.setStreams (i, o);
        }
    
        public HttpPrincipal getPrincipal () {
            return impl.getPrincipal();
        }
    
        ExchangeImpl getExchangeImpl () {
            return impl;
        }
    }
    

    下面是sun.net.httpserver包中ExchangeImpl类的实现,该类中保存了TCP连接输入输出流的引用,

    package sun.net.httpserver;
    
    import java.io.*;
    import java.nio.*;
    import java.nio.channels.*;
    import java.net.*;
    import javax.net.ssl.*;
    import java.util.*;
    import java.text.*;
    import sun.net.www.MessageHeader;
    import com.sun.net.httpserver.*;
    import com.sun.net.httpserver.spi.*;
    
    class ExchangeImpl {
    
        Headers reqHdrs, rspHdrs;
        Request req;
        String method;
        URI uri;
        HttpConnection connection;
        int reqContentLen;
        long rspContentLen;
        /* raw streams which access the socket directly */
        InputStream ris;
        OutputStream ros;
        Thread thread;
        /* close the underlying connection when this exchange finished */
        boolean close;
        boolean closed;
        boolean http10 = false;
    
        /* for formatting the Date: header */
        static TimeZone tz;
        static DateFormat df;
        static {
            String pattern = "EEE, dd MMM yyyy HH:mm:ss zzz";
            tz = TimeZone.getTimeZone ("GMT");
            df = new SimpleDateFormat (pattern, Locale.US);
            df.setTimeZone (tz);
        }
    
        /* streams which take care of the HTTP protocol framing
         * and are passed up to higher layers
         */
        InputStream uis;
        OutputStream uos;
        LeftOverInputStream uis_orig; // uis may have be a user supplied wrapper
        PlaceholderOutputStream uos_orig;
    
        boolean sentHeaders; /* true after response headers sent */
        Map<String,Object> attributes;
        int rcode = -1;
        HttpPrincipal principal;
        ServerImpl server;
    
        ExchangeImpl (
            String m, URI u, Request req, int len, HttpConnection connection
        ) throws IOException {
            this.req = req;
            this.reqHdrs = req.headers();
            this.rspHdrs = new Headers();
            this.method = m;
            this.uri = u;
            this.connection = connection;
            this.reqContentLen = len;
            /* ros only used for headers, body written directly to stream */
            this.ros = req.outputStream();
            this.ris = req.inputStream();
            server = getServerImpl();
            server.startExchange();
        }
    
        public Headers getRequestHeaders () {
            return new UnmodifiableHeaders (reqHdrs);
        }
    
        public Headers getResponseHeaders () {
            return rspHdrs;
        }
    
        public URI getRequestURI () {
            return uri;
        }
    
        public String getRequestMethod (){
            return method;
        }
    
        public HttpContextImpl getHttpContext (){
            return connection.getHttpContext();
        }
    
        public void close () {
            if (closed) {
                return;
            }
            closed = true;
    
            /* close the underlying connection if,
             * a) the streams not set up yet, no response can be sent, or
             * b) if the wrapper output stream is not set up, or
             * c) if the close of the input/outpu stream fails
             */
            try {
                if (uis_orig == null || uos == null) {
                    connection.close();
                    return;
                }
                if (!uos_orig.isWrapped()) {
                    connection.close();
                    return;
                }
                if (!uis_orig.isClosed()) {
                    uis_orig.close();
                }
                uos.close();
            } catch (IOException e) {
                connection.close();
            }
        }
    
        public InputStream getRequestBody () {
            if (uis != null) {
                return uis;
            }
            if (reqContentLen == -1) {
                uis_orig = new ChunkedInputStream (this, ris);
                uis = uis_orig;
            } else {
                uis_orig = new FixedLengthInputStream (this, ris, reqContentLen);
                uis = uis_orig;
            }
            return uis;
        }
    
        LeftOverInputStream getOriginalInputStream () {
            return uis_orig;
        }
    
        public int getResponseCode () {
            return rcode;
        }
    
        public OutputStream getResponseBody () {
            /* TODO. Change spec to remove restriction below. Filters
             * cannot work with this restriction
             *
             * if (!sentHeaders) {
             *    throw new IllegalStateException ("headers not sent");
             * }
             */
            if (uos == null) {
                uos_orig = new PlaceholderOutputStream (null);
                uos = uos_orig;
            }
            return uos;
        }
    
    
        /* returns the place holder stream, which is the stream
         * returned from the 1st call to getResponseBody()
         * The "real" ouputstream is then placed inside this
         */
        PlaceholderOutputStream getPlaceholderResponseBody () {
            getResponseBody();
            return uos_orig;
        }
    
        public void sendResponseHeaders (int rCode, long contentLen)
        throws IOException
        {
            if (sentHeaders) {
                throw new IOException ("headers already sent");
            }
            this.rcode = rCode;
            String statusLine = "HTTP/1.1 "+rCode+Code.msg(rCode)+"
    ";
            OutputStream tmpout = new BufferedOutputStream (ros);
            PlaceholderOutputStream o = getPlaceholderResponseBody();
            tmpout.write (bytes(statusLine, 0), 0, statusLine.length());
            boolean noContentToSend = false; // assume there is content
            rspHdrs.set ("Date", df.format (new Date()));
            if (contentLen == 0) {
                if (http10) {
                    o.setWrappedStream (new UndefLengthOutputStream (this, ros));
                    close = true;
                } else {
                    rspHdrs.set ("Transfer-encoding", "chunked");
                    o.setWrappedStream (new ChunkedOutputStream (this, ros));
                }
            } else {
                if (contentLen == -1) {
                    noContentToSend = true;
                    contentLen = 0;
                }
                /* content len might already be set, eg to implement HEAD resp */
                if (rspHdrs.getFirst ("Content-length") == null) {
                    rspHdrs.set ("Content-length", Long.toString(contentLen));
                }
                o.setWrappedStream (new FixedLengthOutputStream (this, ros, contentLen));
            }
            write (rspHdrs, tmpout);
            this.rspContentLen = contentLen;
            tmpout.flush() ;
            tmpout = null;
            sentHeaders = true;
            if (noContentToSend) {
                WriteFinishedEvent e = new WriteFinishedEvent (this);
                server.addEvent (e);
                closed = true;
            }
            server.logReply (rCode, req.requestLine(), null);
        }
    
        void write (Headers map, OutputStream os) throws IOException {
            Set<Map.Entry<String,List<String>>> entries = map.entrySet();
            for (Map.Entry<String,List<String>> entry : entries) {
                String key = entry.getKey();
                byte[] buf;
                List<String> values = entry.getValue();
                for (String val : values) {
                    int i = key.length();
                    buf = bytes (key, 2);
                    buf[i++] = ':';
                    buf[i++] = ' ';
                    os.write (buf, 0, i);
                    buf = bytes (val, 2);
                    i = val.length();
                    buf[i++] = '
    ';
                    buf[i++] = '
    ';
                    os.write (buf, 0, i);
                }
            }
            os.write ('
    ');
            os.write ('
    ');
        }
    
        private byte[] rspbuf = new byte [128]; // used by bytes()
    
        /**
         * convert string to byte[], using rspbuf
         * Make sure that at least "extra" bytes are free at end
         * of rspbuf. Reallocate rspbuf if not big enough.
         * caller must check return value to see if rspbuf moved
         */
        private byte[] bytes (String s, int extra) {
            int slen = s.length();
            if (slen+extra > rspbuf.length) {
                int diff = slen + extra - rspbuf.length;
                rspbuf = new byte [2* (rspbuf.length + diff)];
            }
            char c[] = s.toCharArray();
            for (int i=0; i<c.length; i++) {
                rspbuf[i] = (byte)c[i];
            }
            return rspbuf;
        }
    
        public InetSocketAddress getRemoteAddress (){
            Socket s = connection.getChannel().socket();
            InetAddress ia = s.getInetAddress();
            int port = s.getPort();
            return new InetSocketAddress (ia, port);
        }
    
        public InetSocketAddress getLocalAddress (){
            Socket s = connection.getChannel().socket();
            InetAddress ia = s.getLocalAddress();
            int port = s.getLocalPort();
            return new InetSocketAddress (ia, port);
        }
    
        public String getProtocol (){
            String reqline = req.requestLine();
            int index = reqline.lastIndexOf (' ');
            return reqline.substring (index+1);
        }
    
        public SSLSession getSSLSession () {
            SSLEngine e = connection.getSSLEngine();
            if (e == null) {
                return null;
            }
            return e.getSession();
        }
    
        public Object getAttribute (String name) {
            if (name == null) {
                throw new NullPointerException ("null name parameter");
            }
            if (attributes == null) {
                attributes = getHttpContext().getAttributes();
            }
            return attributes.get (name);
        }
    
        public void setAttribute (String name, Object value) {
            if (name == null) {
                throw new NullPointerException ("null name parameter");
            }
            if (attributes == null) {
                attributes = getHttpContext().getAttributes();
            }
            attributes.put (name, value);
        }
    
        public void setStreams (InputStream i, OutputStream o) {
            assert uis != null;
            if (i != null) {
                uis = i;
            }
            if (o != null) {
                uos = o;
            }
        }
    
        /**
         * PP
         */
        HttpConnection getConnection () {
            return connection;
        }
    
        ServerImpl getServerImpl () {
            return getHttpContext().getServerImpl();
        }
    
        public HttpPrincipal getPrincipal () {
            return principal;
        }
    
        void setPrincipal (HttpPrincipal principal) {
            this.principal = principal;
        }
    
        static ExchangeImpl get (HttpExchange t) {
            if (t instanceof HttpExchangeImpl) {
                return ((HttpExchangeImpl)t).getExchangeImpl();
            } else {
                assert t instanceof HttpsExchangeImpl;
                return ((HttpsExchangeImpl)t).getExchangeImpl();
            }
        }
    }
    
    /**
     * An OutputStream which wraps another stream
     * which is supplied either at creation time, or sometime later.
     * If a caller/user tries to write to this stream before
     * the wrapped stream has been provided, then an IOException will
     * be thrown.
     */
    class PlaceholderOutputStream extends java.io.OutputStream {
    
        OutputStream wrapped;
    
        PlaceholderOutputStream (OutputStream os) {
            wrapped = os;
        }
    
        void setWrappedStream (OutputStream os) {
            wrapped = os;
        }
    
        boolean isWrapped () {
            return wrapped != null;
        }
    
        private void checkWrap () throws IOException {
            if (wrapped == null) {
                throw new IOException ("response headers not sent yet");
            }
        }
    
        public void write(int b) throws IOException {
            checkWrap();
            wrapped.write (b);
        }
    
        public void write(byte b[]) throws IOException {
            checkWrap();
            wrapped.write (b);
        }
    
        public void write(byte b[], int off, int len) throws IOException {
            checkWrap();
            wrapped.write (b, off, len);
        }
    
        public void flush() throws IOException {
            checkWrap();
            wrapped.flush();
        }
    
        public void close() throws IOException {
            checkWrap();
            wrapped.close();
        }
    }
    

    下面是一个输出流的装饰类

    package sun.net.httpserver;
    
    import java.io.*;
    import com.sun.net.httpserver.*;
    import com.sun.net.httpserver.spi.*;
    
    /**
     * a (filter) input stream which can tell us if bytes are "left over"
     * on the underlying stream which can be read (without blocking)
     * on another instance of this class.
     *
     * The class can also report if all bytes "expected" to be read
     * were read, by the time close() was called. In that case,
     * bytes may be drained to consume them (by calling drain() ).
     *
     * isEOF() returns true, when all expected bytes have been read
     */
    abstract class LeftOverInputStream extends FilterInputStream {
        ExchangeImpl t;
        ServerImpl server;
        protected boolean closed = false;
        protected boolean eof = false;
        byte[] one = new byte [1];
    
        public LeftOverInputStream (ExchangeImpl t, InputStream src) {
            super (src);
            this.t = t;
            this.server = t.getServerImpl();
        }
        /**
         * if bytes are left over buffered on *the UNDERLYING* stream
         */
        public boolean isDataBuffered () throws IOException {
            assert eof;
            return super.available() > 0;
        }
    
        public void close () throws IOException {
            if (closed) {
                return;
            }
            closed = true;
            if (!eof) {
                eof = drain (ServerConfig.getDrainAmount());
            }
        }
    
        public boolean isClosed () {
            return closed;
        }
    
        public boolean isEOF () {
            return eof;
        }
    
        protected abstract int readImpl (byte[]b, int off, int len) throws IOException;
    
        public synchronized int read () throws IOException {
            if (closed) {
                throw new IOException ("Stream is closed");
            }
            int c = readImpl (one, 0, 1);
            if (c == -1 || c == 0) {
                return c;
            } else {
                return one[0] & 0xFF;
            }
        }
    
        public synchronized int read (byte[]b, int off, int len) throws IOException {
            if (closed) {
                throw new IOException ("Stream is closed");
            }
            return readImpl (b, off, len);
        }
    
        /**
         * read and discard up to l bytes or "eof" occurs,
         * (whichever is first). Then return true if the stream
         * is at eof (ie. all bytes were read) or false if not
         * (still bytes to be read)
         */
        public boolean drain (long l) throws IOException {
            int bufSize = 2048;
            byte[] db = new byte [bufSize];
            while (l > 0) {
                long len = readImpl (db, 0, bufSize);
                if (len == -1) {
                    eof = true;
                    return true;
                } else {
                    l = l - len;
                }
            }
            return false;
        }
    }
    

      

    package sun.net.httpserver;
    
    import java.io.*;
    import javax.net.ssl.*;
    import java.nio.channels.*;
    import java.util.logging.Logger;
    import com.sun.net.httpserver.*;
    import com.sun.net.httpserver.spi.*;
    
    /**
     * encapsulates all the connection specific state for a HTTP/S connection
     * one of these is hung from the selector attachment and is used to locate
     * everything from that.
     */
    class HttpConnection {
    
        HttpContextImpl context;
        SSLEngine engine;
        SSLContext sslContext;
        SSLStreams sslStreams;
    
        /* high level streams returned to application */
        InputStream i;
    
        /* low level stream that sits directly over channel */
        InputStream raw;
        OutputStream rawout;
    
        SocketChannel chan;
        SelectionKey selectionKey;
        String protocol;
        long time;
        int remaining;
        boolean closed = false;
        Logger logger;
    
        public String toString() {
            String s = null;
            if (chan != null) {
                s = chan.toString();
            }
            return s;
        }
    
        HttpConnection () {
        }
    
        void setChannel (SocketChannel c) {
            chan = c;
        }
    
        void setContext (HttpContextImpl ctx) {
            context = ctx;
        }
    
        void setParameters (
            InputStream in, OutputStream rawout, SocketChannel chan,
            SSLEngine engine, SSLStreams sslStreams, SSLContext sslContext, String protocol,
            HttpContextImpl context, InputStream raw
        )
        {
            this.context = context;
            this.i = in;
            this.rawout = rawout;
            this.raw = raw;
            this.protocol = protocol;
            this.engine = engine;
            this.chan = chan;
            this.sslContext = sslContext;
            this.sslStreams = sslStreams;
            this.logger = context.getLogger();
        }
    
        SocketChannel getChannel () {
            return chan;
        }
    
        synchronized void close () {
            if (closed) {
                return;
            }
            closed = true;
            if (logger != null && chan != null) {
                logger.finest ("Closing connection: " + chan.toString());
            }
    
            if (!chan.isOpen()) {
                ServerImpl.dprint ("Channel already closed");
                return;
            }
            try {
                /* need to ensure temporary selectors are closed */
                if (raw != null) {
                    raw.close();
                }
            } catch (IOException e) {
                ServerImpl.dprint (e);
            }
            try {
                if (rawout != null) {
                    rawout.close();
                }
            } catch (IOException e) {
                ServerImpl.dprint (e);
            }
            try {
                if (sslStreams != null) {
                    sslStreams.close();
                }
            } catch (IOException e) {
                ServerImpl.dprint (e);
            }
            try {
                chan.close();
            } catch (IOException e) {
                ServerImpl.dprint (e);
            }
        }
    
        /* remaining is the number of bytes left on the lowest level inputstream
         * after the exchange is finished
         */
        void setRemaining (int r) {
            remaining = r;
        }
    
        int getRemaining () {
            return remaining;
        }
    
        SelectionKey getSelectionKey () {
            return selectionKey;
        }
    
        InputStream getInputStream () {
                return i;
        }
    
        OutputStream getRawOutputStream () {
                return rawout;
        }
    
        String getProtocol () {
                return protocol;
        }
    
        SSLEngine getSSLEngine () {
                return engine;
        }
    
        SSLContext getSSLContext () {
                return sslContext;
        }
    
        HttpContextImpl getHttpContext () {
                return context;
        }
    }
    

      

     

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  • 原文地址:https://www.cnblogs.com/wuxinliulei/p/4992633.html
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