Android example source code file (TestWebServer.java)

This example Android source code file (TestWebServer.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

acceptthread, android, date, default_timeout, hashtable, http_version_string, io, ioexception, net, network, post_method, socket, socketexception, string, testwebserver, unknown_method, util, utilities, vector, worker

The TestWebServer.java Android example source code

/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed 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.
 */

package android.core;

import android.util.Log;

import java.io.*;
import java.lang.Thread;
import java.net.*;
import java.util.*;

/**
 * TestWebServer is a simulated controllable test server that
 * can respond to requests from HTTP clients.
 *
 * The server can be controlled to change how it reacts to any
 * requests, and can be told to simulate various events (such as
 * network failure) that would happen in a real environment.
 */
class TestWebServer implements HttpConstants {

    /* static class data/methods */

    /* The ANDROID_LOG_TAG */
    private final static String LOGTAG = "httpsv";

    /* Where worker threads stand idle */
    Vector threads = new Vector();

    /* List of all active worker threads */
    Vector activeThreads = new Vector();

    /* timeout on client connections */
    int timeout = 0;

    /* max # worker threads */
    int workers = 5;

    /* Default port for this server to listen on */
    final static int DEFAULT_PORT = 8080;

    /* Default socket timeout value */
    final static int DEFAULT_TIMEOUT = 5000;

    /* Version string (configurable) */
    protected String HTTP_VERSION_STRING = "HTTP/1.1";

    /* Indicator for whether this server is configured as a HTTP/1.1
     * or HTTP/1.0 server
     */
    private boolean http11 = true;

    /* The thread handling new requests from clients */
    private AcceptThread acceptT;

    /* timeout on client connections */
    int mTimeout;

    /* Server port */
    int mPort;

    /* Switch on/off logging */
    boolean mLog = false;

    /* If set, this will keep connections alive after a request has been
     * processed.
     */
    boolean keepAlive = true;

    /* If set, this will cause response data to be sent in 'chunked' format */
    boolean chunked = false;

    /* If set, this will indicate a new redirection host */
    String redirectHost = null;

    /* If set, this indicates the reason for redirection */
    int redirectCode = -1;

    /* Set the number of connections the server will accept before shutdown */
    int acceptLimit = 100;

    /* Count of number of accepted connections */
    int acceptedConnections = 0;

    public TestWebServer() {
    }

    /**
     * Initialize a new server with default port and timeout.
     * @param log Set true if you want trace output
     */
    public void initServer(boolean log) throws Exception {
        initServer(DEFAULT_PORT, DEFAULT_TIMEOUT, log);
    }

    /**
     * Initialize a new server with default timeout.
     * @param port Sets the server to listen on this port
     * @param log Set true if you want trace output
     */
    public void initServer(int port, boolean log) throws Exception {
        initServer(port, DEFAULT_TIMEOUT, log);
    }

    /**
     * Initialize a new server with default port and timeout.
     * @param port Sets the server to listen on this port
     * @param timeout Indicates the period of time to wait until a socket is
     *                closed
     * @param log Set true if you want trace output
     */
    public void initServer(int port, int timeout, boolean log) throws Exception {
        mPort = port;
        mTimeout = timeout;
        mLog = log;
        keepAlive = true;

        if (acceptT == null) {
            acceptT = new AcceptThread();
            acceptT.init();
            acceptT.start();
        }
    }

    /**
     * Print to the log file (if logging enabled)
     * @param s String to send to the log
     */
    protected void log(String s) {
        if (mLog) {
            Log.d(LOGTAG, s);
        }
    }

    /**
     * Set the server to be an HTTP/1.0 or HTTP/1.1 server.
     * This should be called prior to any requests being sent
     * to the server.
     * @param set True for the server to be HTTP/1.1, false for HTTP/1.0
     */
    public void setHttpVersion11(boolean set) {
        http11 = set;
        if (set) {
            HTTP_VERSION_STRING = "HTTP/1.1";
        } else {
            HTTP_VERSION_STRING = "HTTP/1.0";
        }
    }

    /**
     * Call this to determine whether server connection should remain open
     * @param value Set true to keep connections open after a request
     *              completes
     */
    public void setKeepAlive(boolean value) {
        keepAlive = value;
    }

    /**
     * Call this to indicate whether chunked data should be used
     * @param value Set true to make server respond with chunk encoded
     *              content data.
     */
    public void setChunked(boolean value) {
        chunked = value;
    }

    /**
     * Call this to specify the maximum number of sockets to accept
     * @param limit The number of sockets to accept
     */
    public void setAcceptLimit(int limit) {
        acceptLimit = limit;
    }

    /**
     * Call this to indicate redirection port requirement.
     * When this value is set, the server will respond to a request with
     * a redirect code with the Location response header set to the value
     * specified.
     * @param redirect The location to be redirected to
     * @param redirectCode The code to send when redirecting
     */
    public void setRedirect(String redirect, int code) {
        redirectHost = redirect;
        redirectCode = code;
        log("Server will redirect output to "+redirect+" code "+code);
    }

    /**
     * Cause the thread accepting connections on the server socket to close
     */
    public void close() {
        /* Stop the Accept thread */
        if (acceptT != null) {
            log("Closing AcceptThread"+acceptT);
            acceptT.close();
            acceptT = null;
        }
    }
    /**
     * The AcceptThread is responsible for initiating worker threads
     * to handle incoming requests from clients.
     */
    class AcceptThread extends Thread {

        ServerSocket ss = null;
        boolean running = false;

        public void init() {
            // Networking code doesn't support ServerSocket(port) yet
            InetSocketAddress ia = new InetSocketAddress(mPort);
            while (true) {
                try {
                    ss = new ServerSocket();
                    // Socket timeout functionality is not available yet
                    //ss.setSoTimeout(5000);
                    ss.setReuseAddress(true);
                    ss.bind(ia);
                    break;
                } catch (IOException e) {
                    log("IOException in AcceptThread.init()");                    
                    e.printStackTrace();
                    // wait and retry
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e1) {
                        // TODO Auto-generated catch block
                        e1.printStackTrace();
                    }
                }
            }
        }

        /**
         * Main thread responding to new connections
         */
        public synchronized void run() {
            running = true;
            try {
                while (running) {
                    // Log.d(LOGTAG, "TestWebServer run() calling accept()");
                    Socket s = ss.accept();
                    acceptedConnections++;
                    if (acceptedConnections >= acceptLimit) {
                        running = false;
                    }

                    Worker w = null;
                    synchronized (threads) {
                        if (threads.isEmpty()) {
                            Worker ws = new Worker();
                            ws.setSocket(s);
                            activeThreads.addElement(ws);
                            (new Thread(ws, "additional worker")).start();
                        } else {
                            w = (Worker) threads.elementAt(0);
                            threads.removeElementAt(0);
                            w.setSocket(s);
                        }
                    }
                }
            } catch (SocketException e) {
                log("SocketException in AcceptThread: probably closed during accept");
                running = false;
            } catch (IOException e) {
                log("IOException in AcceptThread");
                e.printStackTrace();
                running = false;
            }
            log("AcceptThread terminated" + this);
        }

        // Close this socket
        public void close() {
            try {
                running = false;
                /* Stop server socket from processing further. Currently
                   this does not cause the SocketException from ss.accept
                   therefore the acceptLimit functionality has been added
                   to circumvent this limitation */
                ss.close();

                // Stop worker threads from continuing
                for (Enumeration e = activeThreads.elements(); e.hasMoreElements();) {
                    Worker w = (Worker)e.nextElement();
                    w.close();
                }
                activeThreads.clear();

            } catch (IOException e) {
                /* We are shutting down the server, so we expect
                 * things to die. Don't propagate.
                 */
                log("IOException caught by server socket close");
            }
        }
    }

    // Size of buffer for reading from the connection
    final static int BUF_SIZE = 2048;

    /* End of line byte sequence */
    static final byte[] EOL = {(byte)'\r', (byte)'\n' };

    /**
     * The worker thread handles all interactions with a current open
     * connection. If pipelining is turned on, this will allow this
     * thread to continuously operate on numerous requests before the
     * connection is closed.
     */
    class Worker implements HttpConstants, Runnable {

        /* buffer to use to hold request data */
        byte[] buf;

        /* Socket to client we're handling */
        private Socket s;

        /* Reference to current request method ID */
        private int requestMethod;

        /* Reference to current requests test file/data */
        private String testID;

        /* Reference to test number from testID */
        private int testNum;

        /* Reference to whether new request has been initiated yet */
        private boolean readStarted;

        /* Indicates whether current request has any data content */
        private boolean hasContent = false;

        boolean running = false;

        /* Request headers are stored here */
        private Hashtable<String, String> headers = new Hashtable();

        /* Create a new worker thread */
        Worker() {
            buf = new byte[BUF_SIZE];
            s = null;
        }

        /**
         * Called by the AcceptThread to unblock this Worker to process
         * a request.
         * @param s The socket on which the connection has been made
         */
        synchronized void setSocket(Socket s) {
            this.s = s;
            notify();
        }

        /**
         * Called by the accept thread when it's closing. Potentially unblocks
         * the worker thread to terminate properly
         */
        synchronized void close() {
            running = false;
            notify();
        }

        /**
         * Main worker thread. This will wait until a request has
         * been identified by the accept thread upon which it will
         * service the thread.
         */
        public synchronized void run() {
            running = true;
            while(running) {
                if (s == null) {
                    /* nothing to do */
                    try {
                        log(this+" Moving to wait state");
                        wait();
                    } catch (InterruptedException e) {
                        /* should not happen */
                        continue;
                    }
                    if (!running) break;
                }
                try {
                    handleClient();
                } catch (Exception e) {
                    e.printStackTrace();
                }
                /* go back in wait queue if there's fewer
                 * than numHandler connections.
                 */
                s = null;
                Vector pool = threads;
                synchronized (pool) {
                    if (pool.size() >= workers) {
                        /* too many threads, exit this one */
                        activeThreads.remove(this);
                        return;
                    } else {
                        pool.addElement(this);
                    }
                }
            }
            log(this+" terminated");
        }

        /**
         * Zero out the buffer from last time
         */
        private void clearBuffer() {
            for (int i = 0; i < BUF_SIZE; i++) {
                buf[i] = 0;
            }
        }

        /**
         * Utility method to read a line of data from the input stream
         * @param is Inputstream to read
         * @return number of bytes read
         */
        private int readOneLine(InputStream is) {

            int read = 0;

            clearBuffer();
            try {
                log("Reading one line: started ="+readStarted+" avail="+is.available());
                while ((!readStarted) || (is.available() > 0)) {
                    int data = is.read();
                    // We shouldn't get EOF but we need tdo check
                    if (data == -1) {
                        log("EOF returned");
                        return -1;
                    }

                    buf[read] = (byte)data;

                    System.out.print((char)data);

                    readStarted = true;
                    if (buf[read++]==(byte)'\n') {
                        System.out.println();
                        return read;
                    }
                }
            } catch (IOException e) {
                log("IOException from readOneLine");
                e.printStackTrace();
            }
            return read;
        }

        /**
         * Read a chunk of data
         * @param is Stream from which to read data
         * @param length Amount of data to read
         * @return number of bytes read
         */
        private int readData(InputStream is, int length) {
            int read = 0;
            int count;
            // At the moment we're only expecting small data amounts
            byte[] buf = new byte[length];

            try {
                while (is.available() > 0) {
                    count = is.read(buf, read, length-read);
                    read += count;
                }
            } catch (IOException e) {
                log("IOException from readData");
                e.printStackTrace();
            }
            return read;
        }

        /**
         * Read the status line from the input stream extracting method
         * information.
         * @param is Inputstream to read
         * @return number of bytes read
         */
        private int parseStatusLine(InputStream is) {
            int index;
            int nread = 0;

            log("Parse status line");
            // Check for status line first
            nread = readOneLine(is);
            // Bomb out if stream closes prematurely
            if (nread == -1) {
                requestMethod = UNKNOWN_METHOD;
                return -1;
            }

            if (buf[0] == (byte)'G' &&
                buf[1] == (byte)'E' &&
                buf[2] == (byte)'T' &&
                buf[3] == (byte)' ') {
                requestMethod = GET_METHOD;
                log("GET request");
                index = 4;
            } else if (buf[0] == (byte)'H' &&
                       buf[1] == (byte)'E' &&
                       buf[2] == (byte)'A' &&
                       buf[3] == (byte)'D' &&
                       buf[4] == (byte)' ') {
                requestMethod = HEAD_METHOD;
                log("HEAD request");
                index = 5;
            } else if (buf[0] == (byte)'P' &&
                       buf[1] == (byte)'O' &&
                       buf[2] == (byte)'S' &&
                       buf[3] == (byte)'T' &&
                       buf[4] == (byte)' ') {
                requestMethod = POST_METHOD;
                log("POST request");
                index = 5;
            } else {
                // Unhandled request
                requestMethod = UNKNOWN_METHOD;
                return -1;
            }

            // A valid method we understand
            if (requestMethod > UNKNOWN_METHOD) {
                // Read file name
                int i = index;
                while (buf[i] != (byte)' ') {
                    // There should be HTTP/1.x at the end
                    if ((buf[i] == (byte)'\n') || (buf[i] == (byte)'\r')) {
                        requestMethod = UNKNOWN_METHOD;
                        return -1;
                    }
                    i++;
                }

                testID = new String(buf, 0, index, i-index);
                if (testID.startsWith("/")) {
                    testID = testID.substring(1);
                }

                return nread;
            }
            return -1;
        }

        /**
         * Read a header from the input stream
         * @param is Inputstream to read
         * @return number of bytes read
         */
        private int parseHeader(InputStream is) {
            int index = 0;
            int nread = 0;
            log("Parse a header");
            // Check for status line first
            nread = readOneLine(is);
            // Bomb out if stream closes prematurely
            if (nread == -1) {
                requestMethod = UNKNOWN_METHOD;
                return -1;
            }
            // Read header entry 'Header: data'
            int i = index;
            while (buf[i] != (byte)':') {
                // There should be an entry after the header

                if ((buf[i] == (byte)'\n') || (buf[i] == (byte)'\r')) {
                    return UNKNOWN_METHOD;
                }
                i++;
            }

            String headerName = new String(buf, 0, i);
            i++; // Over ':'
            while (buf[i] == ' ') {
                i++;
            }
            String headerValue = new String(buf, i, nread-1);

            headers.put(headerName, headerValue);
            return nread;
        }

        /**
         * Read all headers from the input stream
         * @param is Inputstream to read
         * @return number of bytes read
         */
        private int readHeaders(InputStream is) {
            int nread = 0;
            log("Read headers");
            // Headers should be terminated by empty CRLF line
            while (true) {
                int headerLen = 0;
                headerLen = parseHeader(is);
                if (headerLen == -1)
                    return -1;
                nread += headerLen;
                if (headerLen <= 2) {
                    return nread;
                }
            }
        }

        /**
         * Read content data from the input stream
         * @param is Inputstream to read
         * @return number of bytes read
         */
        private int readContent(InputStream is) {
            int nread = 0;
            log("Read content");
            String lengthString = headers.get(requestHeaders[REQ_CONTENT_LENGTH]);
            int length = new Integer(lengthString).intValue();

            // Read content
            length = readData(is, length);
            return length;
        }

        /**
         * The main loop, reading requests.
         */
        void handleClient() throws IOException {
            InputStream is = new BufferedInputStream(s.getInputStream());
            PrintStream ps = new PrintStream(s.getOutputStream());
            int nread = 0;

            /* we will only block in read for this many milliseconds
             * before we fail with java.io.InterruptedIOException,
             * at which point we will abandon the connection.
             */
            s.setSoTimeout(mTimeout);
            s.setTcpNoDelay(true);

            do {
                nread = parseStatusLine(is);
                if (requestMethod != UNKNOWN_METHOD) {

                    // If status line found, read any headers
                    nread = readHeaders(is);

                    // Then read content (if any)
                    // TODO handle chunked encoding from the client
                    if (headers.get(requestHeaders[REQ_CONTENT_LENGTH]) != null) {
                        nread = readContent(is);
                    }
                } else {
                    if (nread > 0) {
                        /* we don't support this method */
                        ps.print(HTTP_VERSION_STRING + " " + HTTP_BAD_METHOD +
                                 " unsupported method type: ");
                        ps.write(buf, 0, 5);
                        ps.write(EOL);
                        ps.flush();
                    } else {
                    }
                    if (!keepAlive || nread <= 0) {
                        headers.clear();
                        readStarted = false;

                        log("SOCKET CLOSED");
                        s.close();
                        return;
                    }
                }

                // Reset test number prior to outputing data
                testNum = -1;

                // Write out the data
                printStatus(ps);
                printHeaders(ps);

                // Write line between headers and body
                psWriteEOL(ps);

                // Write the body
                if (redirectCode == -1) {
                    switch (requestMethod) {
                        case GET_METHOD:
                            if ((testNum < 0) || (testNum > TestWebData.tests.length - 1)) {
                                send404(ps);
                            } else {
                                sendFile(ps);
                            }
                            break;
                        case HEAD_METHOD:
                            // Nothing to do
                            break;
                        case POST_METHOD:
                            // Post method write body data
                            if ((testNum > 0) || (testNum < TestWebData.tests.length - 1)) {
                                sendFile(ps);
                            }

                            break;
                        default:
                            break;
                    }
                } else { // Redirecting
                    switch (redirectCode) {
                        case 301:
                            // Seems 301 needs a body by neon (although spec
                            // says SHOULD).
                            psPrint(ps, TestWebData.testServerResponse[TestWebData.REDIRECT_301]);
                            break;
                        case 302:
                            //
                            psPrint(ps, TestWebData.testServerResponse[TestWebData.REDIRECT_302]);
                            break;
                        case 303:
                            psPrint(ps, TestWebData.testServerResponse[TestWebData.REDIRECT_303]);
                            break;
                        case 307:
                            psPrint(ps, TestWebData.testServerResponse[TestWebData.REDIRECT_307]);
                            break;
                        default:
                            break;
                    }
                }

                ps.flush();

                // Reset for next request
                readStarted = false;
                headers.clear();

            } while (keepAlive);

            log("SOCKET CLOSED");
            s.close();
        }

        // Print string to log and output stream
        void psPrint(PrintStream ps, String s) throws IOException {
            log(s);
            ps.print(s);
        }

        // Print bytes to log and output stream
        void psWrite(PrintStream ps, byte[] bytes, int len) throws IOException {
            log(new String(bytes));
            ps.write(bytes, 0, len);
        }

        // Print CRLF to log and output stream
        void psWriteEOL(PrintStream ps) throws IOException {
            log("CRLF");
            ps.write(EOL);
        }


        // Print status to log and output stream
        void printStatus(PrintStream ps) throws IOException {
            // Handle redirects first.
            if (redirectCode != -1) {
                log("REDIRECTING TO "+redirectHost+" status "+redirectCode);
                psPrint(ps, HTTP_VERSION_STRING + " " + redirectCode +" Moved permanently");
                psWriteEOL(ps);
                psPrint(ps, "Location: " + redirectHost);
                psWriteEOL(ps);
                return;
            }


            if (testID.startsWith("test")) {
                testNum = Integer.valueOf(testID.substring(4))-1;
            }

            if ((testNum < 0) || (testNum > TestWebData.tests.length - 1)) {
                psPrint(ps, HTTP_VERSION_STRING + " " + HTTP_NOT_FOUND + " not found");
                psWriteEOL(ps);
            }  else {
                psPrint(ps, HTTP_VERSION_STRING + " " + HTTP_OK+" OK");
                psWriteEOL(ps);
            }

            log("Status sent");
        }
        /**
         * Create the server response and output to the stream
         * @param ps The PrintStream to output response headers and data to
         */
        void printHeaders(PrintStream ps) throws IOException {
            psPrint(ps,"Server: TestWebServer"+mPort);
            psWriteEOL(ps);
            psPrint(ps, "Date: " + (new Date()));
            psWriteEOL(ps);
            psPrint(ps, "Connection: " + ((keepAlive) ? "Keep-Alive" : "Close"));
            psWriteEOL(ps);

            // Yuk, if we're not redirecting, we add the file details
            if (redirectCode == -1) {

                if (!TestWebData.testParams[testNum].testDir) {
                    if (chunked) {
                        psPrint(ps, "Transfer-Encoding: chunked");
                    } else {
                        psPrint(ps, "Content-length: "+TestWebData.testParams[testNum].testLength);
                    }
                    psWriteEOL(ps);

                    psPrint(ps,"Last Modified: " + (new
                                                    Date(TestWebData.testParams[testNum].testLastModified)));
                    psWriteEOL(ps);

                    psPrint(ps, "Content-type: " + TestWebData.testParams[testNum].testType);
                    psWriteEOL(ps);
                } else {
                    psPrint(ps, "Content-type: text/html");
                    psWriteEOL(ps);
                }
            } else {
                // Content-length of 301, 302, 303, 307 are the same.
                psPrint(ps, "Content-length: "+(TestWebData.testServerResponse[TestWebData.REDIRECT_301]).length());
                psWriteEOL(ps);
                psWriteEOL(ps);
            }
            log("Headers sent");

        }

        /**
         * Sends the 404 not found message
         * @param ps The PrintStream to write to
         */
        void send404(PrintStream ps) throws IOException {
            ps.println("Not Found\n\n"+
                       "The requested resource was not found.\n");
        }

        /**
         * Sends the data associated with the headers
         * @param ps The PrintStream to write to
         */
        void sendFile(PrintStream ps) throws IOException {
            // For now just make a chunk with the whole of the test data
            // It might be worth making this multiple chunks for large
            // test data to test multiple chunks.
            int dataSize = TestWebData.tests[testNum].length;
            if (chunked) {
                psPrint(ps, Integer.toHexString(dataSize));
                psWriteEOL(ps);
                psWrite(ps, TestWebData.tests[testNum], dataSize);
                psWriteEOL(ps);
                psPrint(ps, "0");
                psWriteEOL(ps);
                psWriteEOL(ps);
            } else {
                psWrite(ps, TestWebData.tests[testNum], dataSize);
            }
        }
    }
}