cms/corbaservices/MiniWebServer.java

/* 
 * i-scream central monitoring system
 * http://www.i-scream.org.uk
 * Copyright (C) 2000-2002 i-scream
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

//---PACKAGE DECLARATION---
package uk.org.iscream.cms.corbaservices;

//---IMPORTS---
import java.net.*;
import java.io.*;
import java.util.*;

/**
 * MiniWebServer
 *
 * This provides a very basic webserver for serving IOR files.
 * This could easily serve other text files, but not binaries.
 *
 * @author  $Author: tdb $
 * @version $Id: MiniWebServer.java,v 1.8 2002/05/18 18:15:56 tdb Exp $
 */
public class MiniWebServer extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.8 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
    
    /**
     * Construct a new MiniWebServer
     *
     * @param port The port to bind to
     * @param okUrlsConfig The URL list config file
     * @param webDir The web directory
     */
    public MiniWebServer(int port, String okUrlsConfig, String webDir) {
        _port = port;
        _okUrlsConfig = okUrlsConfig;
        _webDir = webDir;
    }

//---PUBLIC METHODS---

    /**
     * Main thread of execution. Keeps looping spawning off
     * Handler's to deal with each client. This should keep
     * going, and extra care has been taking with error
     * catching.
     */
    public void run() {
        // carry on forever
        while(true) {
            boolean run = true;
            ServerSocket serverSocket = null;
            try {
                serverSocket = new ServerSocket(_port);
            } catch (IOException e) {
                run = false;
                System.out.println(e);
                e.printStackTrace();
            }
            while(run) {
                try {
                    // get a new client and give it to a Handler
                    Socket socket = serverSocket.accept();
                    Handler handler = new Handler(socket);
                    handler.start();
                } catch (IOException e) {
                    run=false;
                    System.out.println(e);
                    e.printStackTrace();
                }
            }
        }
    }

//---PRIVATE METHODS---

    /**
     * Reads a file in given an URL. Very basic, and has only
     * been tested to work for URL's in the / directory.
     *
     * @param url The URL given to the webserver
     * @return A String containing data from the file
     */
    private String readUrl(String url) {
        // trim off the initial /
        if(url.startsWith("/")) {
            url = url.substring(1);
        }
        try {
            // need to prefix with web directory
            File file = new File(_webDir+"/"+url);
            if(file.exists() && file.canRead()) {
                // read in all the data
                String data = "";
                BufferedReader reader = new BufferedReader(new FileReader(file));
                while(reader.ready()) {
                    String line = reader.readLine();
                    if(line != null) {
                        data += line + "\n";
                    }
                }
                return data;
            }
            else {
                // return null if we can't read it
                return null;
            }
        } catch (IOException e) {
            System.out.println(e);
            e.printStackTrace();
            return null;
        }
    }
    
    /**
     * Checks if an URL is allowed. Failure of this method
     * indicates a client should be sent a 403.
     *
     * @param url the url to check
     * @return whether the url is permitted
     */
    private boolean okUrl(String url) {
        // recheck the list - this means the list can be
        // changed on the fly :)
        readOkUrls();
        Iterator i = _okUrls.iterator();
        while(i.hasNext()) {
            if(url.equals((String)i.next())) {
                // matched url against our list
                return true;
            }
        }
        return false;
    }
    
    /**
     * Reads the list of URLs into a list.
     */
    private void readOkUrls() {
        File file = new File(_okUrlsConfig);
        long lastMod = file.lastModified();
        // only want to re-read the list if it's changed
        if(lastMod > _okUrlsConfigStamp) {
            _okUrlsConfigStamp = lastMod;
            _okUrls = new LinkedList();
            if(file.exists() && file.canRead()) {
                try {
                    BufferedReader reader = new BufferedReader(new FileReader(file));
                    while(reader.ready()) {
                        String line = reader.readLine();
                        // ignore comments
                        if(!line.startsWith("#")) {
                            _okUrls.add(line);
                        }
                    }
                } catch(IOException e) {
                    System.out.println(e);
                    e.printStackTrace();
                }
            }
        }
    }
    
//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---
    
    /**
     * The port we're bound to.
     */
    private int _port;
    
    /**
     * List of URLs that are permitted
     */
    private LinkedList _okUrls;
    
    /**
     * Config file for the URL list
     */
    private String _okUrlsConfig;
    
    /**
     * Timestamp of the URL config file
     */
    private long _okUrlsConfigStamp = 0;
    
    /**
     * Web directory
     */
    private String _webDir;

//---STATIC ATTRIBUTES---

//---INNER CLASSES---
    
    /**
     * A Handler to deal with each client. This is an inner
     * class because I felt like trying it out :)
     */
    private class Handler extends Thread {
        
        /**
         * Construct a new Handler
         *
         * @param socket The socket connected to the client
         */
        public Handler(Socket socket) {
            _socket = socket;
        }
        
        /**
         * Start the Handler running. This will read the URL
         * from the client, and respond accordinly.
         *
         * This does not try to deal with bad data
         */
        public void run() {
            BufferedReader reader = null;
            PrintWriter writer = null;
            try {
                // setup the reader and writer
                reader = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
                writer = new PrintWriter(_socket.getOutputStream(), true);
                String line= "";
                String url = "";
                // keep reading from the client until it sends no more...
                do {
                    line = reader.readLine();
                    // ah, this contains the URL
                    if(line.startsWith("GET ")) {
                        // strip off "GET "
                        url = line.substring(4);
                        // strip off anything past the URL
                        if(url.lastIndexOf(' ') != -1) {
                            url = url.substring(0, url.lastIndexOf(' '));
                        }
                    }
                } while(!line.equals(""));
                // check the URL is allowed
                if(okUrl(url)) {
                    // read the file
                    String data = readUrl(url);
                    // check the file could be read, null means it couldn't
                    if(data != null) {
                        writer.println(data);
                    }
                    else {
                        // oh dear, couldn't find it, send a 404
                        writer.println("HTTP/1.1 404 Not Found\n");
                        writer.println("404 Not Found");
                    }
                }
                else {
                    // oh dear, not allowed, send a 403
                    writer.println("HTTP/1.1 403 Permission Denied\n");
                    writer.println("403 Permission Denied");
                }
            } catch(IOException e) {
                System.out.println(e);
                e.printStackTrace();
            }
            // clean up and close
            try {
                reader.close();
                writer.close();
                _socket.close();
            } catch(IOException e) {
                System.out.println(e);
                e.printStackTrace();
            }
        }
        
        /**
         * The socket connected to the client
         */
        private Socket _socket;
    }
    
}
Revision:	1.9
Committed:	Tue May 21 16:47:11 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.8:	+4 -3 lines
Log Message:	Added URL to GPL headers.
#	User	Rev	Content
1	tdb	1.8	/*
2	tdb	1.9	* i-scream central monitoring system
3			* http://www.i-scream.org.uk
4	tdb	1.8	* Copyright (C) 2000-2002 i-scream
5			*
6			* This program is free software; you can redistribute it and/or
7			* modify it under the terms of the GNU General Public License
8			* as published by the Free Software Foundation; either version 2
9			* of the License, or (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19			*/
20
21	tdb	1.1	//---PACKAGE DECLARATION---
22	tdb	1.6	package uk.org.iscream.cms.corbaservices;
23	tdb	1.1
24			//---IMPORTS---
25			import java.net.*;
26			import java.io.*;
27			import java.util.*;
28
29			/**
30			* MiniWebServer
31			*
32	tdb	1.3	* This provides a very basic webserver for serving IOR files.
33			* This could easily serve other text files, but not binaries.
34			*
35	tdb	1.7	* @author $Author: tdb $
36	tdb	1.9	* @version $Id: MiniWebServer.java,v 1.8 2002/05/18 18:15:56 tdb Exp $
37	tdb	1.1	*/
38			public class MiniWebServer extends Thread {
39
40			//---FINAL ATTRIBUTES---
41
42			/**
43			* The current CVS revision of this class
44			*/
45	tdb	1.9	public static final String REVISION = "$Revision: 1.8 $";
46	tdb	1.1
47			//---STATIC METHODS---
48
49			//---CONSTRUCTORS---
50	tdb	1.3
51			/**
52			* Construct a new MiniWebServer
53			*
54			* @param port The port to bind to
55			* @param okUrlsConfig The URL list config file
56			* @param webDir The web directory
57			*/
58	tdb	1.2	public MiniWebServer(int port, String okUrlsConfig, String webDir) {
59	tdb	1.1	_port = port;
60			_okUrlsConfig = okUrlsConfig;
61	tdb	1.2	_webDir = webDir;
62	tdb	1.1	}
63
64			//---PUBLIC METHODS---
65
66	tdb	1.3	/**
67			* Main thread of execution. Keeps looping spawning off
68			* Handler's to deal with each client. This should keep
69			* going, and extra care has been taking with error
70			* catching.
71			*/
72	tdb	1.1	public void run() {
73			// carry on forever
74			while(true) {
75			boolean run = true;
76			ServerSocket serverSocket = null;
77			try {
78			serverSocket = new ServerSocket(_port);
79			} catch (IOException e) {
80			run = false;
81			System.out.println(e);
82			e.printStackTrace();
83			}
84			while(run) {
85			try {
86	tdb	1.3	// get a new client and give it to a Handler
87	tdb	1.1	Socket socket = serverSocket.accept();
88			Handler handler = new Handler(socket);
89			handler.start();
90			} catch (IOException e) {
91			run=false;
92			System.out.println(e);
93			e.printStackTrace();
94			}
95			}
96			}
97			}
98
99			//---PRIVATE METHODS---
100
101	tdb	1.3	/**
102			* Reads a file in given an URL. Very basic, and has only
103			* been tested to work for URL's in the / directory.
104			*
105			* @param url The URL given to the webserver
106			* @return A String containing data from the file
107			*/
108	tdb	1.1	private String readUrl(String url) {
109	tdb	1.3	// trim off the initial /
110	tdb	1.1	if(url.startsWith("/")) {
111			url = url.substring(1);
112			}
113			try {
114	tdb	1.3	// need to prefix with web directory
115	tdb	1.2	File file = new File(_webDir+"/"+url);
116	tdb	1.1	if(file.exists() && file.canRead()) {
117	tdb	1.3	// read in all the data
118	tdb	1.1	String data = "";
119			BufferedReader reader = new BufferedReader(new FileReader(file));
120			while(reader.ready()) {
121	tdb	1.4	String line = reader.readLine();
122			if(line != null) {
123			data += line + "\n";
124			}
125	tdb	1.1	}
126			return data;
127			}
128			else {
129	tdb	1.3	// return null if we can't read it
130	tdb	1.1	return null;
131			}
132			} catch (IOException e) {
133			System.out.println(e);
134			e.printStackTrace();
135			return null;
136			}
137			}
138	tdb	1.3
139			/**
140			* Checks if an URL is allowed. Failure of this method
141			* indicates a client should be sent a 403.
142			*
143			* @param url the url to check
144			* @return whether the url is permitted
145			*/
146	tdb	1.1	private boolean okUrl(String url) {
147	tdb	1.3	// recheck the list - this means the list can be
148			// changed on the fly :)
149	tdb	1.1	readOkUrls();
150			Iterator i = _okUrls.iterator();
151			while(i.hasNext()) {
152			if(url.equals((String)i.next())) {
153	tdb	1.3	// matched url against our list
154	tdb	1.1	return true;
155			}
156			}
157			return false;
158			}
159
160	tdb	1.3	/**
161			* Reads the list of URLs into a list.
162			*/
163	tdb	1.1	private void readOkUrls() {
164			File file = new File(_okUrlsConfig);
165			long lastMod = file.lastModified();
166	tdb	1.3	// only want to re-read the list if it's changed
167	tdb	1.1	if(lastMod > _okUrlsConfigStamp) {
168			_okUrlsConfigStamp = lastMod;
169			_okUrls = new LinkedList();
170			if(file.exists() && file.canRead()) {
171			try {
172			BufferedReader reader = new BufferedReader(new FileReader(file));
173			while(reader.ready()) {
174			String line = reader.readLine();
175	tdb	1.3	// ignore comments
176	tdb	1.1	if(!line.startsWith("#")) {
177			_okUrls.add(line);
178			}
179			}
180			} catch(IOException e) {
181			System.out.println(e);
182			e.printStackTrace();
183			}
184			}
185			}
186			}
187
188			//---ACCESSOR/MUTATOR METHODS---
189
190			//---ATTRIBUTES---
191	tdb	1.3
192			/**
193			* The port we're bound to.
194			*/
195	tdb	1.1	private int _port;
196	tdb	1.3
197			/**
198			* List of URLs that are permitted
199			*/
200	tdb	1.1	private LinkedList _okUrls;
201	tdb	1.3
202			/**
203			* Config file for the URL list
204			*/
205	tdb	1.1	private String _okUrlsConfig;
206	tdb	1.3
207			/**
208			* Timestamp of the URL config file
209			*/
210	tdb	1.1	private long _okUrlsConfigStamp = 0;
211	tdb	1.3
212			/**
213			* Web directory
214			*/
215	tdb	1.2	private String _webDir;
216	tdb	1.1
217			//---STATIC ATTRIBUTES---
218
219			//---INNER CLASSES---
220	tdb	1.3
221			/**
222			* A Handler to deal with each client. This is an inner
223			* class because I felt like trying it out :)
224			*/
225	tdb	1.1	private class Handler extends Thread {
226	tdb	1.3
227			/**
228			* Construct a new Handler
229			*
230			* @param socket The socket connected to the client
231			*/
232	tdb	1.1	public Handler(Socket socket) {
233			_socket = socket;
234			}
235	tdb	1.3
236			/**
237			* Start the Handler running. This will read the URL
238			* from the client, and respond accordinly.
239			*
240			* This does not try to deal with bad data
241			*/
242	tdb	1.1	public void run() {
243			BufferedReader reader = null;
244			PrintWriter writer = null;
245			try {
246	tdb	1.3	// setup the reader and writer
247	tdb	1.1	reader = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
248			writer = new PrintWriter(_socket.getOutputStream(), true);
249			String line= "";
250			String url = "";
251	tdb	1.3	// keep reading from the client until it sends no more...
252	tdb	1.1	do {
253			line = reader.readLine();
254	tdb	1.3	// ah, this contains the URL
255	tdb	1.7	if(line.startsWith("GET ")) {
256	tdb	1.3	// strip off "GET "
257	tdb	1.1	url = line.substring(4);
258	tdb	1.3	// strip off anything past the URL
259	tdb	1.7	if(url.lastIndexOf(' ') != -1) {
260			url = url.substring(0, url.lastIndexOf(' '));
261			}
262	tdb	1.1	}
263			} while(!line.equals(""));
264	tdb	1.3	// check the URL is allowed
265	tdb	1.1	if(okUrl(url)) {
266	tdb	1.3	// read the file
267	tdb	1.1	String data = readUrl(url);
268	tdb	1.3	// check the file could be read, null means it couldn't
269	tdb	1.1	if(data != null) {
270			writer.println(data);
271			}
272			else {
273	tdb	1.3	// oh dear, couldn't find it, send a 404
274	tdb	1.1	writer.println("HTTP/1.1 404 Not Found\n");
275			writer.println("404 Not Found");
276			}
277			}
278			else {
279	tdb	1.3	// oh dear, not allowed, send a 403
280	tdb	1.1	writer.println("HTTP/1.1 403 Permission Denied\n");
281			writer.println("403 Permission Denied");
282			}
283			} catch(IOException e) {
284			System.out.println(e);
285			e.printStackTrace();
286			}
287	tdb	1.3	// clean up and close
288	tdb	1.1	try {
289			reader.close();
290			writer.close();
291			_socket.close();
292			} catch(IOException e) {
293			System.out.println(e);
294			e.printStackTrace();
295			}
296			}
297	tdb	1.3
298			/**
299			* The socket connected to the client
300			*/
301	tdb	1.1	private Socket _socket;
302			}
303
304			}