httpcore-nio/src/examples/org/apache/http/examples/nio/NHttpFileServer.java

/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */
package org.apache.http.examples.nio;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.net.InetSocketAddress;
import java.net.URLDecoder;
import java.nio.channels.FileChannel;

import org.apache.http.HttpEntityEnclosingRequest;
import org.apache.http.HttpException;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.HttpResponseInterceptor;
import org.apache.http.HttpStatus;
import org.apache.http.impl.DefaultConnectionReuseStrategy;
import org.apache.http.impl.DefaultHttpResponseFactory;
import org.apache.http.impl.nio.DefaultServerIOEventDispatch;
import org.apache.http.impl.nio.reactor.DefaultListeningIOReactor;
import org.apache.http.nio.ContentDecoder;
import org.apache.http.nio.ContentDecoderChannel;
import org.apache.http.nio.FileContentDecoder;
import org.apache.http.nio.IOControl;
import org.apache.http.nio.NHttpConnection;
import org.apache.http.nio.entity.ConsumingNHttpEntity;
import org.apache.http.nio.entity.ConsumingNHttpEntityTemplate;
import org.apache.http.nio.entity.ContentListener;
import org.apache.http.nio.entity.NFileEntity;
import org.apache.http.nio.entity.NStringEntity;
import org.apache.http.nio.protocol.AsyncNHttpServiceHandler;
import org.apache.http.nio.protocol.EventListener;
import org.apache.http.nio.protocol.NHttpRequestHandler;
import org.apache.http.nio.protocol.NHttpRequestHandlerResolver;
import org.apache.http.nio.protocol.SimpleNHttpRequestHandler;
import org.apache.http.nio.reactor.IOEventDispatch;
import org.apache.http.nio.reactor.ListeningIOReactor;
import org.apache.http.params.CoreConnectionPNames;
import org.apache.http.params.CoreProtocolPNames;
import org.apache.http.params.HttpParams;
import org.apache.http.params.SyncBasicHttpParams;
import org.apache.http.protocol.HttpContext;
import org.apache.http.protocol.HttpProcessor;
import org.apache.http.protocol.ImmutableHttpProcessor;
import org.apache.http.protocol.ResponseConnControl;
import org.apache.http.protocol.ResponseContent;
import org.apache.http.protocol.ResponseDate;
import org.apache.http.protocol.ResponseServer;

/**
 * Basic, yet fully functional and spec compliant, HTTP/1.1 file server based on the non-blocking 
 * I/O model.
 * <p>
 * Please note the purpose of this application is demonstrate the usage of HttpCore APIs.
 * It is NOT intended to demonstrate the most efficient way of building an HTTP file server. 
 * 
 *
 */
public class NHttpFileServer {

    public static void main(String[] args) throws Exception {
        if (args.length < 1) {
            System.err.println("Please specify document root directory");
            System.exit(1);
        }

        boolean useFileChannels = true;
        if (args.length >= 2) {
            String s = args[1];
            if (s.equalsIgnoreCase("disableFileChannels")) {
                useFileChannels = false;
            }
        }

        HttpParams params = new SyncBasicHttpParams();
        params
            .setIntParameter(CoreConnectionPNames.SO_TIMEOUT, 20000)
            .setIntParameter(CoreConnectionPNames.SOCKET_BUFFER_SIZE, 8 * 1024)
            .setBooleanParameter(CoreConnectionPNames.STALE_CONNECTION_CHECK, false)
            .setBooleanParameter(CoreConnectionPNames.TCP_NODELAY, true)
            .setParameter(CoreProtocolPNames.ORIGIN_SERVER, "HttpComponents/1.1");

        HttpProcessor httpproc = new ImmutableHttpProcessor(new HttpResponseInterceptor[] {
                new ResponseDate(),
                new ResponseServer(),
                new ResponseContent(),
                new ResponseConnControl()
        });
        
        AsyncNHttpServiceHandler handler = new AsyncNHttpServiceHandler(
                httpproc,
                new DefaultHttpResponseFactory(),
                new DefaultConnectionReuseStrategy(),
                params);

        final HttpFileHandler filehandler = new HttpFileHandler(args[0], useFileChannels);

        NHttpRequestHandlerResolver resolver = new NHttpRequestHandlerResolver() {

            public NHttpRequestHandler lookup(String requestURI) {
                return filehandler;
            }

        };

        handler.setHandlerResolver(resolver);

        // Provide an event logger
        handler.setEventListener(new EventLogger());

        IOEventDispatch ioEventDispatch = new DefaultServerIOEventDispatch(handler, params);
        ListeningIOReactor ioReactor = new DefaultListeningIOReactor(2, params);
        try {
            ioReactor.listen(new InetSocketAddress(8080));
            ioReactor.execute(ioEventDispatch);
        } catch (InterruptedIOException ex) {
            System.err.println("Interrupted");
        } catch (IOException e) {
            System.err.println("I/O error: " + e.getMessage());
        }
        System.out.println("Shutdown");
    }

    static class HttpFileHandler extends SimpleNHttpRequestHandler {

        private final String docRoot;
        private final boolean useFileChannels;

        public HttpFileHandler(final String docRoot, boolean useFileChannels) {
            this.docRoot = docRoot;
            this.useFileChannels = useFileChannels;
        }

        public ConsumingNHttpEntity entityRequest(
                final HttpEntityEnclosingRequest request,
                final HttpContext context) throws HttpException, IOException {
            return new ConsumingNHttpEntityTemplate(
                    request.getEntity(),
                    new FileWriteListener(useFileChannels));
        }

        @Override
        public void handle(
                final HttpRequest request,
                final HttpResponse response,
                final HttpContext context) throws HttpException, IOException {
            String target = request.getRequestLine().getUri();
            final File file = new File(this.docRoot, URLDecoder.decode(target, "UTF-8"));
            if (!file.exists()) {
                response.setStatusCode(HttpStatus.SC_NOT_FOUND);
                NStringEntity entity = new NStringEntity(
                        "<html><body><h1>File" + file.getPath() +
                        " not found</h1></body></html>",
                        "UTF-8");
                entity.setContentType("text/html; charset=UTF-8");
                response.setEntity(entity);
            } else if (!file.canRead() || file.isDirectory()) {
                response.setStatusCode(HttpStatus.SC_FORBIDDEN);
                NStringEntity entity = new NStringEntity(
                        "<html><body><h1>Access denied</h1></body></html>",
                        "UTF-8");
                entity.setContentType("text/html; charset=UTF-8");
                response.setEntity(entity);
            } else {
                response.setStatusCode(HttpStatus.SC_OK);
                NFileEntity entity = new NFileEntity(file, "text/html", useFileChannels);
                response.setEntity(entity);
            }
        }

    }

    static class FileWriteListener implements ContentListener {
        private final File file;
        private final FileOutputStream outputFile;
        private final FileChannel fileChannel;
        private final boolean useFileChannels;
        private long idx = 0;

        public FileWriteListener(boolean useFileChannels) throws IOException {
            this.file = File.createTempFile("tmp", ".tmp", null);
            this.outputFile = new FileOutputStream(file, true);
            this.fileChannel = outputFile.getChannel();
            this.useFileChannels = useFileChannels;
        }

        public void contentAvailable(ContentDecoder decoder, IOControl ioctrl)
                throws IOException {
            long transferred;
            if(useFileChannels && decoder instanceof FileContentDecoder) {
                transferred = ((FileContentDecoder) decoder).transfer(
                        fileChannel, idx, Long.MAX_VALUE);
            } else {
                transferred = fileChannel.transferFrom(
                        new ContentDecoderChannel(decoder), idx, Integer.MAX_VALUE);
            }

            if(transferred > 0)
                idx += transferred;
        }

        public void finished() {
            try {
                outputFile.close();
            } catch(IOException ignored) {}
            try {
                fileChannel.close();
            } catch(IOException ignored) {}
        }
    }

    static class EventLogger implements EventListener {

        public void connectionOpen(final NHttpConnection conn) {
            System.out.println("Connection open: " + conn);
        }

        public void connectionTimeout(final NHttpConnection conn) {
            System.out.println("Connection timed out: " + conn);
        }

        public void connectionClosed(final NHttpConnection conn) {
            System.out.println("Connection closed: " + conn);
        }

        public void fatalIOException(final IOException ex, final NHttpConnection conn) {
            System.err.println("I/O error: " + ex.getMessage());
        }

        public void fatalProtocolException(final HttpException ex, final NHttpConnection conn) {
            System.err.println("HTTP error: " + ex.getMessage());
        }

    }

}