cms/corbaservices/MiniWebServer.java

/* 
 * i-scream central monitoring system
 * 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 1.7 2002/04/05 11:54:35 tdb Exp $
 */
public class MiniWebServer extends Thread {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public static final String REVISION = "$Revision: 1.7 $";
    
//---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:	1.8
Committed:	Sat May 18 18:15:56 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.7:	+21 -2 lines
Log Message:	i-scream is now licensed under the GPL. I've added the GPL headers to every source file, and put a full copy of the license in the appropriate places. I think I've covered everything. This is going to be a mad commit ;)
#	User	Rev	Content
1	tdb	1.8	/*
2			* i-scream central monitoring system
3			* Copyright (C) 2000-2002 i-scream
4			*
5			* This program is free software; you can redistribute it and/or
6			* modify it under the terms of the GNU General Public License
7			* as published by the Free Software Foundation; either version 2
8			* of the License, or (at your option) any later version.
9			*
10			* This program is distributed in the hope that it will be useful,
11			* but WITHOUT ANY WARRANTY; without even the implied warranty of
12			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13			* GNU General Public License for more details.
14			*
15			* You should have received a copy of the GNU General Public License
16			* along with this program; if not, write to the Free Software
17			* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18			*/
19
20	tdb	1.1	//---PACKAGE DECLARATION---
21	tdb	1.6	package uk.org.iscream.cms.corbaservices;
22	tdb	1.1
23			//---IMPORTS---
24			import java.net.*;
25			import java.io.*;
26			import java.util.*;
27
28			/**
29			* MiniWebServer
30			*
31	tdb	1.3	* This provides a very basic webserver for serving IOR files.
32			* This could easily serve other text files, but not binaries.
33			*
34	tdb	1.7	* @author $Author: tdb $
35	tdb	1.8	* @version $Id: MiniWebServer.java,v 1.7 2002/04/05 11:54:35 tdb Exp $
36	tdb	1.1	*/
37			public class MiniWebServer extends Thread {
38
39			//---FINAL ATTRIBUTES---
40
41			/**
42			* The current CVS revision of this class
43			*/
44	tdb	1.8	public static final String REVISION = "$Revision: 1.7 $";
45	tdb	1.1
46			//---STATIC METHODS---
47
48			//---CONSTRUCTORS---
49	tdb	1.3
50			/**
51			* Construct a new MiniWebServer
52			*
53			* @param port The port to bind to
54			* @param okUrlsConfig The URL list config file
55			* @param webDir The web directory
56			*/
57	tdb	1.2	public MiniWebServer(int port, String okUrlsConfig, String webDir) {
58	tdb	1.1	_port = port;
59			_okUrlsConfig = okUrlsConfig;
60	tdb	1.2	_webDir = webDir;
61	tdb	1.1	}
62
63			//---PUBLIC METHODS---
64
65	tdb	1.3	/**
66			* Main thread of execution. Keeps looping spawning off
67			* Handler's to deal with each client. This should keep
68			* going, and extra care has been taking with error
69			* catching.
70			*/
71	tdb	1.1	public void run() {
72			// carry on forever
73			while(true) {
74			boolean run = true;
75			ServerSocket serverSocket = null;
76			try {
77			serverSocket = new ServerSocket(_port);
78			} catch (IOException e) {
79			run = false;
80			System.out.println(e);
81			e.printStackTrace();
82			}
83			while(run) {
84			try {
85	tdb	1.3	// get a new client and give it to a Handler
86	tdb	1.1	Socket socket = serverSocket.accept();
87			Handler handler = new Handler(socket);
88			handler.start();
89			} catch (IOException e) {
90			run=false;
91			System.out.println(e);
92			e.printStackTrace();
93			}
94			}
95			}
96			}
97
98			//---PRIVATE METHODS---
99
100	tdb	1.3	/**
101			* Reads a file in given an URL. Very basic, and has only
102			* been tested to work for URL's in the / directory.
103			*
104			* @param url The URL given to the webserver
105			* @return A String containing data from the file
106			*/
107	tdb	1.1	private String readUrl(String url) {
108	tdb	1.3	// trim off the initial /
109	tdb	1.1	if(url.startsWith("/")) {
110			url = url.substring(1);
111			}
112			try {
113	tdb	1.3	// need to prefix with web directory
114	tdb	1.2	File file = new File(_webDir+"/"+url);
115	tdb	1.1	if(file.exists() && file.canRead()) {
116	tdb	1.3	// read in all the data
117	tdb	1.1	String data = "";
118			BufferedReader reader = new BufferedReader(new FileReader(file));
119			while(reader.ready()) {
120	tdb	1.4	String line = reader.readLine();
121			if(line != null) {
122			data += line + "\n";
123			}
124	tdb	1.1	}
125			return data;
126			}
127			else {
128	tdb	1.3	// return null if we can't read it
129	tdb	1.1	return null;
130			}
131			} catch (IOException e) {
132			System.out.println(e);
133			e.printStackTrace();
134			return null;
135			}
136			}
137	tdb	1.3
138			/**
139			* Checks if an URL is allowed. Failure of this method
140			* indicates a client should be sent a 403.
141			*
142			* @param url the url to check
143			* @return whether the url is permitted
144			*/
145	tdb	1.1	private boolean okUrl(String url) {
146	tdb	1.3	// recheck the list - this means the list can be
147			// changed on the fly :)
148	tdb	1.1	readOkUrls();
149			Iterator i = _okUrls.iterator();
150			while(i.hasNext()) {
151			if(url.equals((String)i.next())) {
152	tdb	1.3	// matched url against our list
153	tdb	1.1	return true;
154			}
155			}
156			return false;
157			}
158
159	tdb	1.3	/**
160			* Reads the list of URLs into a list.
161			*/
162	tdb	1.1	private void readOkUrls() {
163			File file = new File(_okUrlsConfig);
164			long lastMod = file.lastModified();
165	tdb	1.3	// only want to re-read the list if it's changed
166	tdb	1.1	if(lastMod > _okUrlsConfigStamp) {
167			_okUrlsConfigStamp = lastMod;
168			_okUrls = new LinkedList();
169			if(file.exists() && file.canRead()) {
170			try {
171			BufferedReader reader = new BufferedReader(new FileReader(file));
172			while(reader.ready()) {
173			String line = reader.readLine();
174	tdb	1.3	// ignore comments
175	tdb	1.1	if(!line.startsWith("#")) {
176			_okUrls.add(line);
177			}
178			}
179			} catch(IOException e) {
180			System.out.println(e);
181			e.printStackTrace();
182			}
183			}
184			}
185			}
186
187			//---ACCESSOR/MUTATOR METHODS---
188
189			//---ATTRIBUTES---
190	tdb	1.3
191			/**
192			* The port we're bound to.
193			*/
194	tdb	1.1	private int _port;
195	tdb	1.3
196			/**
197			* List of URLs that are permitted
198			*/
199	tdb	1.1	private LinkedList _okUrls;
200	tdb	1.3
201			/**
202			* Config file for the URL list
203			*/
204	tdb	1.1	private String _okUrlsConfig;
205	tdb	1.3
206			/**
207			* Timestamp of the URL config file
208			*/
209	tdb	1.1	private long _okUrlsConfigStamp = 0;
210	tdb	1.3
211			/**
212			* Web directory
213			*/
214	tdb	1.2	private String _webDir;
215	tdb	1.1
216			//---STATIC ATTRIBUTES---
217
218			//---INNER CLASSES---
219	tdb	1.3
220			/**
221			* A Handler to deal with each client. This is an inner
222			* class because I felt like trying it out :)
223			*/
224	tdb	1.1	private class Handler extends Thread {
225	tdb	1.3
226			/**
227			* Construct a new Handler
228			*
229			* @param socket The socket connected to the client
230			*/
231	tdb	1.1	public Handler(Socket socket) {
232			_socket = socket;
233			}
234	tdb	1.3
235			/**
236			* Start the Handler running. This will read the URL
237			* from the client, and respond accordinly.
238			*
239			* This does not try to deal with bad data
240			*/
241	tdb	1.1	public void run() {
242			BufferedReader reader = null;
243			PrintWriter writer = null;
244			try {
245	tdb	1.3	// setup the reader and writer
246	tdb	1.1	reader = new BufferedReader(new InputStreamReader(_socket.getInputStream()));
247			writer = new PrintWriter(_socket.getOutputStream(), true);
248			String line= "";
249			String url = "";
250	tdb	1.3	// keep reading from the client until it sends no more...
251	tdb	1.1	do {
252			line = reader.readLine();
253	tdb	1.3	// ah, this contains the URL
254	tdb	1.7	if(line.startsWith("GET ")) {
255	tdb	1.3	// strip off "GET "
256	tdb	1.1	url = line.substring(4);
257	tdb	1.3	// strip off anything past the URL
258	tdb	1.7	if(url.lastIndexOf(' ') != -1) {
259			url = url.substring(0, url.lastIndexOf(' '));
260			}
261	tdb	1.1	}
262			} while(!line.equals(""));
263	tdb	1.3	// check the URL is allowed
264	tdb	1.1	if(okUrl(url)) {
265	tdb	1.3	// read the file
266	tdb	1.1	String data = readUrl(url);
267	tdb	1.3	// check the file could be read, null means it couldn't
268	tdb	1.1	if(data != null) {
269			writer.println(data);
270			}
271			else {
272	tdb	1.3	// oh dear, couldn't find it, send a 404
273	tdb	1.1	writer.println("HTTP/1.1 404 Not Found\n");
274			writer.println("404 Not Found");
275			}
276			}
277			else {
278	tdb	1.3	// oh dear, not allowed, send a 403
279	tdb	1.1	writer.println("HTTP/1.1 403 Permission Denied\n");
280			writer.println("403 Permission Denied");
281			}
282			} catch(IOException e) {
283			System.out.println(e);
284			e.printStackTrace();
285			}
286	tdb	1.3	// clean up and close
287	tdb	1.1	try {
288			reader.close();
289			writer.close();
290			_socket.close();
291			} catch(IOException e) {
292			System.out.println(e);
293			e.printStackTrace();
294			}
295			}
296	tdb	1.3
297			/**
298			* The socket connected to the client
299			*/
300	tdb	1.1	private Socket _socket;
301			}
302
303			}