server/core/ConfigurationManagerServant.java

//---PACKAGE DECLARATION---
package uk.org.iscream.core;

//---IMPORTS---
import uk.org.iscream.util.*;
import uk.org.iscream.componentmanager.*;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.*;
import java.io.*;

/**
 * This class is essentially a Configuration factory.
 * This class implements the Configurator IDL and allows
 * other classes in the system ot obtain their Configuration
 *
 * On construction it requires a reference to the RootPOA
 * to allow it to create Configuration objects to be
 * returned.
 *
 * It also relies on the System.properties to set internal values.
 *
 * ###
 * A point to note is that this class does NOT yet manage
 * created configurations which may cause memory problems!
 * ###
 *
 * @author  $Author: tdb1 $
 * @version $Id: ConfigurationManagerServant.java,v 1.16 2001/03/14 23:25:29 tdb1 Exp $
 */
class ConfigurationManagerServant extends ConfigurationManagerPOA {

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.16 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---

    /**
     * Creates a new ConfiguratorServant
     * This class uses the System.properties to set internal values
     */
    ConfigurationManagerServant() {
        // assign some local variables
        _configPath = System.getProperty("uk.org.iscream.ConfigurationLocation");
        _systemConfigFile = System.getProperty("uk.org.iscream.SystemConfigurationFile");

        // load the system config
        loadSystemConfig();

        // log our status
        _logger.write(toString(), Logger.SYSINIT, "started");
        _logger.write(toString(), Logger.SYSMSG, "configuration location - " + _configPath);
        _logger.write(toString(), Logger.SYSMSG, "system configuration file - " + _systemConfigFile);
    }

//---PUBLIC METHODS---
    
    /**
     * Returns a Configuration object which contains
     * the configuration data requested by the calling
     * object.
     *
     * This method will look in the systemConfig file
     * for an entry for this "source", if there is no
     * entry it returns a refernce to the system
     * config.  If there are any errors in reading the 
     * configuration, it returns null, the caller is 
     * expected to be able to handle this.
     *
     * This method also checks to see if the system.conf
     * file has been updated and reloads its reference if
     * needed.
     *
     * @param source the configuration required
     * @return the Configuration
     */
    public Configuration getConfiguration(String source) {
        _logger.write(toString(), Logger.SYSMSG, "got request for " + source);

        
        // check to see if we need to reload the system config
        // because it has changed
        if (isModified(_systemConfig.getFileList(), _systemConfig.getLastModified())) {
            _logger.write(toString(), Logger.SYSMSG, "system config changed");
            loadSystemConfig();
        }

        // search config for group membership
        // and obain a list of groups by name
        LinkedList nameGroups = getGroupMembership(source);
        // add the hosts individual config to the start of the list
        nameGroups.addFirst(source);
        
        // this list will be used to compile the groupings
        LinkedList groups = new LinkedList();
                     
        // if we are dealing with a Host.<hostname> request, then we also
        // want to look for ip address details, as configuration entries may relate to it
        // if we can't resolve it, we don't look.
        LinkedList ipGroups = null;
        if (source.startsWith("Host.")) {
            // hostname is after Host.
            String hostname = source.substring(5);
            try {
                String ip = "Host." + InetAddress.getByName(hostname).getHostAddress();
                ipGroups = getGroupMembership(ip);
                ipGroups.addFirst(ip);
                // add to our list of groups
                groups.addAll(ipGroups);
            } catch (UnknownHostException e) {
                _logger.write(toString(), Logger.ERROR, "could not resolve hostname - " + hostname);
            }
        }
        
        // add the rest of the groups to the end        
        groups.addAll(nameGroups);

        Iterator i = groups.iterator();
        String fileList = "";
        while (i.hasNext()) {
            String groupName = (String) i.next();
            _logger.write(toString(), Logger.DEBUG, "looking for config entry for - " + groupName);
            // we look for this entry in the systemConfig
            String configFile = _systemConfig.getProperty("config." + groupName);
            // if there is a config entry then
            if (configFile != null) {
                _logger.write(toString(), Logger.DEBUG, "looking for config tree in - " + configFile);
    
                // get the file list of includes etc + the system config
                String groupFileList = null;
                try {
                    groupFileList = getIncludedFiles(configFile, "") + ";";
                } catch (Exception e) {
                    // not sure what to do here
                    // so we just log the error
                    _logger.write(toString(), Logger.ERROR, "ERROR - " + e);
                }
                if (groupFileList != null) {
                    fileList += groupFileList;
                }
            } else {
                _logger.write(toString(), Logger.DEBUG, "no config entry for - " + groupName);
            }
        }
        // add the system config as the final check
        fileList = _systemConfigFile + ";" + fileList;
        _logger.write(toString(), Logger.DEBUG, "config tree - " + fileList);
        
        // build the configuration
        Configuration config = buildConfiguration(fileList);
        
        // if this is null at this point, then there will have been an error
        return config;
    }
    
    
    /**
     * When passed a file list and a current value for the lastModified
     * of the current configuration, this method compares the value
     * to the actual value of the configuration files to determine 
     * whether or not the configuration has been modified.
     *
     * @param fileList a list of files that the caller uses for configuration
     * @param lastModified the last modified date of the callers configuration
     *
     * @return whether or not the configuration has been modified
     */
    public boolean isModified(String fileList, long lastModified) {
        StringTokenizer st = new StringTokenizer(fileList, ";");
        long newLastModified;
        File currentFile;
        while (st.hasMoreTokens()) {
            currentFile = new File(_configPath, st.nextToken());
            newLastModified = currentFile.lastModified();
            if (newLastModified > lastModified) {
                return true;
            }
        }
        return false;
    }

    /**
     * Overrides the {@link java.lang.Object#toString() Object.toString()}
     * method to provide clean logging (every class should have this).
     *
     * This uses the uk.org.iscream.util.FormatName class
     * to format the toString()
     *
     * @return the name of this class and its CVS revision
     */
    public String toString() {
        return FormatName.getName(
            _name,
            getClass().getName(),
            REVISION);
    }

//---PRIVATE METHODS---

    /**
     * This is a recursive function private to this class.
     * It constructs a hierarchy of files as a ";" serperated
     * string which can be used to read in the configuration.
     * This function calls itself.
     * 
     * @param currentFile the current file to be processed
     * @param readFiles used for recursion purposes only, these are the files it has read so far 
     *
     * @return the current list that has been constructed
     *
     * @throws IOException if there is trouble reading the file
     * @throws FileNotFoundException is there is trouble finding the file
     * @throws CircularIncludeException this is if a circular include is detected
     */
    private String getIncludedFiles(String currentFile, String readFiles) throws IOException, FileNotFoundException, Exception {
        
        // check for circular include here
        if (hasDuplicate(currentFile, readFiles) || currentFile.equals(_systemConfigFile)) {
            throw new CircularIncludeException(currentFile + " is included more than once");
        }
        
        // if there wasn't, we're gonna use this file, so make a note of it as read
        // (note the use of the ";", this is for the hasDuplicate, function)
        readFiles = readFiles + currentFile + ";";

        Properties properties = new Properties();
        properties.load(new FileInputStream(new File(_configPath, currentFile)));
        
        // get the include property
        String includes = properties.getProperty("include");

        // if we're the last file with no includes, return our name
        if (includes == null) {
            return currentFile;
        
        // otherwise, recurse over our includes
        } else {
            StringTokenizer st = new StringTokenizer(includes, ";");
            String returnList= "";
            while (st.hasMoreTokens()) {
                returnList = getIncludedFiles(st.nextToken(), readFiles) + ";" + returnList;
            }
            
            return returnList + currentFile;
        }
    }

    /**
     * This simple method checks to see if a given 
     * file exists in the given list.
     *
     * @param file the file to check the list for
     * @param fileList the list to check
     *
     * @return if the given file appeard in the list
     */
    private boolean hasDuplicate(String file, String fileList) {
        StringTokenizer st = new StringTokenizer(fileList, ";");
        while (st.hasMoreTokens()) {
            if (file.equals(st.nextToken())) {
                return true;
            }
        }
        return false;
    }

    /**
     * Opens and loads the system configuration into the 
     * local reference _systemConfig
     */
    private void loadSystemConfig() {
        _logger.write(this.toString(), Logger.SYSMSG, "reloading " + _systemConfigFile);
        // get a reference to the system config and store it
        try {
            // create the properties for the configuration
            File systemConfigFile = new File(_configPath, _systemConfigFile);
            _systemConfigHolder = new Properties();
            _systemConfigHolder.load(new FileInputStream(systemConfigFile));
            
            // create the servant
            ConfigurationServant ref = new ConfigurationServant(_systemConfigHolder, _systemConfigFile, systemConfigFile.lastModified());
            org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
            
            // narrow it to a Configuration
            _systemConfig = ConfigurationHelper.narrow(objRef);
            
        } catch (Exception e) {
            _logger.write(toString(), Logger.FATAL, "ERROR: " + e.getMessage());
        }
    }

    /**
     * Parses the system configuration file
     * for group membership entries.
     *
     * It looks for all entries of group.<name>
     * which contain the given source name
     *
     * @param source the source to find membership for
     *
     * @return the list of groups that this source is a member of
     */
    private LinkedList getGroupMembership(String source) {
        _logger.write(toString(), Logger.DEBUG, "searching group members for - " + source);
        LinkedList groupMembership = new LinkedList();        
        Iterator i = new TreeSet(_systemConfigHolder.keySet()).iterator();
        while(i.hasNext()) {
            String key = (String) i.next();
            if (key.startsWith("group.")) {
                String group = _systemConfig.getProperty(key);
                // if it is in the group
                if (group.indexOf(source) != -1) {
                    groupMembership.add(key.substring(6));
                
                // if there are wildcards in the group
                } else if (group.indexOf("*") != -1) {
                    // check the wildcards apply to this srce
                    if( wildcardCheck(source, group)) {
                        groupMembership.add(key.substring(6));
                    }
                }
                
            }   
        }
        return groupMembership;
    }    

    /**
     * Checks that a given string is not matched within the
     * given list of strings. eg:<br>
     * <br>
     * Given "stue5de.ukc.ac.uk"<br>
     * And   "raptor.ukc.ac.uk;stue*.ukc.ac.uk<br>
     * <br>
     * This method would return true as there is a match
     * 
     * @param source the string to look for
     * @param group the group to search for a wilcard entry
     *
     * @return if there is a match
     */
    private boolean wildcardCheck(String source, String group) {
        boolean foundMatch = false;
        StringTokenizer st = new StringTokenizer(group, ";");
        // go through all the hosts in the group
        while (st.hasMoreTokens()) {
            String host = st.nextToken();
            // this host has wildcards
            if(host.indexOf("*") != -1) {
                StringTokenizer hostst = new StringTokenizer(host, "*");
                String part = "";
                int index = 0;
                // the first token will be everything at the start
                // unless it starts with a wildcard
                if(!host.startsWith("*")) {
                    part = hostst.nextToken();
                    if (source.startsWith(part)) {
                        foundMatch = true;
                        index = part.length();
                    }
                // all of the start of the string is matched
                } else {
                    foundMatch = true;
                }
                // if the start matched, we want to check the rest...
                if (foundMatch) {
                    while (hostst.hasMoreTokens()) {
                        part = hostst.nextToken();
                        // if the next section can't be matched
                        // then this isn't in the source
                        if(source.substring(index).indexOf(part) == -1) {
                            foundMatch = false;
                            // we don't want to look through any more of it
                            break;
                        } else {
                            foundMatch = true;
                            index += source.substring(index).indexOf(part) + part.length();
                        }
                    }
                    // if we reach here and we've found a match
                    // we want to check that the last part
                    // of the wildcard string is the last part
                    // of the source, if it is, we break out
                    // and finish as we've found a match.
                    // if the end of the wildcard is a *, then
                    // we don't care
                    if (!host.endsWith("*") && foundMatch) {
                        if ((source.endsWith(part))) {
                            _logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
                            break;
                        // if there is no match, say so so we go round again
                        } else {
                            foundMatch = false;
                        }
                    } else if (foundMatch) {
                        _logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
                        break;
                    }
                }
            }
        }
        return foundMatch;
    }


    /**
     * Build the properties as a Configuration to be 
     * returned to the caller
     *
     * @param fileList the list of files to build the configuration from
     *
     * @return the built Configuration
     */
    private Configuration buildConfiguration(String fileList) {
        Configuration config = null;

        // if there is an entry
        if (!fileList.equals("")) {
            try {
                
                // build the properites here from the filelist.... 
                StringTokenizer st = new StringTokenizer(fileList, ";");
                
                // some holders for variables
                File currentFile;
                long lastModified = 0, newLastModified = 0;
                Properties properties = null, prevProperties = null;
                
                // the root of all configurations will be the system config
                // so we need to open the properties of that
                Properties defaultProperties = new Properties();
                
                // This loop then iterates over the file list
                // creates the properties to be passed to the
                // Configuration constructor
                while (st.hasMoreTokens()) {
                    properties = new Properties(defaultProperties);
                    currentFile = new File(_configPath, st.nextToken());
                    newLastModified = currentFile.lastModified();
                    if (newLastModified > lastModified) {
                        lastModified = newLastModified;
                    }
                    properties.load(new FileInputStream(currentFile));
                    defaultProperties = properties;
                }

                // this creates the configuration, all nice, ready to be returned
                ConfigurationServant ref = new ConfigurationServant(properties, fileList, lastModified);
                org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
                config = ConfigurationHelper.narrow(objRef);
                _logger.write(toString(), Logger.DEBUG, "returning built configuration");
            } catch (Exception e) {
                // not sure what to do here
                // so we just log the error
                _logger.write(toString(), Logger.ERROR, "ERROR - " + e);
            }
            
        // if there isn't an entry for the requested config
        } else {
            _logger.write(toString(), Logger.DEBUG, "no configured config, returning " + _systemConfigFile);
            config = _systemConfig;
        }
        return config;
    }

//---ACCESSOR/MUTATOR METHODS---

//---ATTRIBUTES---

    /**
     * This is the friendly identifier of the
     * component this class is running in.
     * eg, a Filter may be called "filter1",
     * If this class does not have an owning
     * component,  a name from the configuration
     * can be placed here.  This name could also
     * be changed to null for utility classes.
     */
    private String _name = Core.NAME;

    /**
     * This holds a reference to the
     * system logger that is being used.
     */
    private Logger _logger = ReferenceManager.getInstance().getLogger();
    
    /**
     * A reference to the reference manager in use
     */
    private ReferenceManager _refman = ReferenceManager.getInstance();
    
    /**
     * The root path to all configurations
     */
    private String _configPath;
    
    /**
     * The name of the file that contains the system configuration
     */
    private String _systemConfigFile;
    
    /**
     * An instance of the system config
     */
    private Configuration _systemConfig;
    
    /**
     * The system config file represented by a
     * properties object.
     */
    private Properties _systemConfigHolder;
    
//---STATIC ATTRIBUTES---
    
}
Revision:	1.17
Committed:	Mon Mar 19 19:12:29 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
CVS Tags:	PROJECT_COMPLETION
Changes since 1.16:	+17 -9 lines
Log Message:	IP groups now have a lower priority than name groups.
#	Content
1	//---PACKAGE DECLARATION---
2	package uk.org.iscream.core;
3
4	//---IMPORTS---
5	import uk.org.iscream.util.*;
6	import uk.org.iscream.componentmanager.*;
7	import java.net.InetAddress;
8	import java.net.UnknownHostException;
9	import java.util.*;
10	import java.io.*;
11
12	/**
13	* This class is essentially a Configuration factory.
14	* This class implements the Configurator IDL and allows
15	* other classes in the system ot obtain their Configuration
16	*
17	* On construction it requires a reference to the RootPOA
18	* to allow it to create Configuration objects to be
19	* returned.
20	*
21	* It also relies on the System.properties to set internal values.
22	*
23	* ###
24	* A point to note is that this class does NOT yet manage
25	* created configurations which may cause memory problems!
26	* ###
27	*
28	* @author $Author: tdb1 $
29	* @version $Id: ConfigurationManagerServant.java,v 1.16 2001/03/14 23:25:29 tdb1 Exp $
30	*/
31	class ConfigurationManagerServant extends ConfigurationManagerPOA {
32
33	//---FINAL ATTRIBUTES---
34
35	/**
36	* The current CVS revision of this class
37	*/
38	public final String REVISION = "$Revision: 1.16 $";
39
40	//---STATIC METHODS---
41
42	//---CONSTRUCTORS---
43
44	/**
45	* Creates a new ConfiguratorServant
46	* This class uses the System.properties to set internal values
47	*/
48	ConfigurationManagerServant() {
49	// assign some local variables
50	_configPath = System.getProperty("uk.org.iscream.ConfigurationLocation");
51	_systemConfigFile = System.getProperty("uk.org.iscream.SystemConfigurationFile");
52
53	// load the system config
54	loadSystemConfig();
55
56	// log our status
57	_logger.write(toString(), Logger.SYSINIT, "started");
58	_logger.write(toString(), Logger.SYSMSG, "configuration location - " + _configPath);
59	_logger.write(toString(), Logger.SYSMSG, "system configuration file - " + _systemConfigFile);
60	}
61
62	//---PUBLIC METHODS---
63
64	/**
65	* Returns a Configuration object which contains
66	* the configuration data requested by the calling
67	* object.
68	*
69	* This method will look in the systemConfig file
70	* for an entry for this "source", if there is no
71	* entry it returns a refernce to the system
72	* config. If there are any errors in reading the
73	* configuration, it returns null, the caller is
74	* expected to be able to handle this.
75	*
76	* This method also checks to see if the system.conf
77	* file has been updated and reloads its reference if
78	* needed.
79	*
80	* @param source the configuration required
81	* @return the Configuration
82	*/
83	public Configuration getConfiguration(String source) {
84	_logger.write(toString(), Logger.SYSMSG, "got request for " + source);
85
86
87	// check to see if we need to reload the system config
88	// because it has changed
89	if (isModified(_systemConfig.getFileList(), _systemConfig.getLastModified())) {
90	_logger.write(toString(), Logger.SYSMSG, "system config changed");
91	loadSystemConfig();
92	}
93
94	// search config for group membership
95	// and obain a list of groups by name
96	LinkedList nameGroups = getGroupMembership(source);
97	// add the hosts individual config to the start of the list
98	nameGroups.addFirst(source);
99
100	// this list will be used to compile the groupings
101	LinkedList groups = new LinkedList();
102
103	// if we are dealing with a Host.<hostname> request, then we also
104	// want to look for ip address details, as configuration entries may relate to it
105	// if we can't resolve it, we don't look.
106	LinkedList ipGroups = null;
107	if (source.startsWith("Host.")) {
108	// hostname is after Host.
109	String hostname = source.substring(5);
110	try {
111	String ip = "Host." + InetAddress.getByName(hostname).getHostAddress();
112	ipGroups = getGroupMembership(ip);
113	ipGroups.addFirst(ip);
114	// add to our list of groups
115	groups.addAll(ipGroups);
116	} catch (UnknownHostException e) {
117	_logger.write(toString(), Logger.ERROR, "could not resolve hostname - " + hostname);
118	}
119	}
120
121	// add the rest of the groups to the end
122	groups.addAll(nameGroups);
123
124	Iterator i = groups.iterator();
125	String fileList = "";
126	while (i.hasNext()) {
127	String groupName = (String) i.next();
128	_logger.write(toString(), Logger.DEBUG, "looking for config entry for - " + groupName);
129	// we look for this entry in the systemConfig
130	String configFile = _systemConfig.getProperty("config." + groupName);
131	// if there is a config entry then
132	if (configFile != null) {
133	_logger.write(toString(), Logger.DEBUG, "looking for config tree in - " + configFile);
134
135	// get the file list of includes etc + the system config
136	String groupFileList = null;
137	try {
138	groupFileList = getIncludedFiles(configFile, "") + ";";
139	} catch (Exception e) {
140	// not sure what to do here
141	// so we just log the error
142	_logger.write(toString(), Logger.ERROR, "ERROR - " + e);
143	}
144	if (groupFileList != null) {
145	fileList += groupFileList;
146	}
147	} else {
148	_logger.write(toString(), Logger.DEBUG, "no config entry for - " + groupName);
149	}
150	}
151	// add the system config as the final check
152	fileList = _systemConfigFile + ";" + fileList;
153	_logger.write(toString(), Logger.DEBUG, "config tree - " + fileList);
154
155	// build the configuration
156	Configuration config = buildConfiguration(fileList);
157
158	// if this is null at this point, then there will have been an error
159	return config;
160	}
161
162
163	/**
164	* When passed a file list and a current value for the lastModified
165	* of the current configuration, this method compares the value
166	* to the actual value of the configuration files to determine
167	* whether or not the configuration has been modified.
168	*
169	* @param fileList a list of files that the caller uses for configuration
170	* @param lastModified the last modified date of the callers configuration
171	*
172	* @return whether or not the configuration has been modified
173	*/
174	public boolean isModified(String fileList, long lastModified) {
175	StringTokenizer st = new StringTokenizer(fileList, ";");
176	long newLastModified;
177	File currentFile;
178	while (st.hasMoreTokens()) {
179	currentFile = new File(_configPath, st.nextToken());
180	newLastModified = currentFile.lastModified();
181	if (newLastModified > lastModified) {
182	return true;
183	}
184	}
185	return false;
186	}
187
188	/**
189	* Overrides the {@link java.lang.Object#toString() Object.toString()}
190	* method to provide clean logging (every class should have this).
191	*
192	* This uses the uk.org.iscream.util.FormatName class
193	* to format the toString()
194	*
195	* @return the name of this class and its CVS revision
196	*/
197	public String toString() {
198	return FormatName.getName(
199	_name,
200	getClass().getName(),
201	REVISION);
202	}
203
204	//---PRIVATE METHODS---
205
206	/**
207	* This is a recursive function private to this class.
208	* It constructs a hierarchy of files as a ";" serperated
209	* string which can be used to read in the configuration.
210	* This function calls itself.
211	*
212	* @param currentFile the current file to be processed
213	* @param readFiles used for recursion purposes only, these are the files it has read so far
214	*
215	* @return the current list that has been constructed
216	*
217	* @throws IOException if there is trouble reading the file
218	* @throws FileNotFoundException is there is trouble finding the file
219	* @throws CircularIncludeException this is if a circular include is detected
220	*/
221	private String getIncludedFiles(String currentFile, String readFiles) throws IOException, FileNotFoundException, Exception {
222
223	// check for circular include here
224	if (hasDuplicate(currentFile, readFiles) \|\| currentFile.equals(_systemConfigFile)) {
225	throw new CircularIncludeException(currentFile + " is included more than once");
226	}
227
228	// if there wasn't, we're gonna use this file, so make a note of it as read
229	// (note the use of the ";", this is for the hasDuplicate, function)
230	readFiles = readFiles + currentFile + ";";
231
232	Properties properties = new Properties();
233	properties.load(new FileInputStream(new File(_configPath, currentFile)));
234
235	// get the include property
236	String includes = properties.getProperty("include");
237
238	// if we're the last file with no includes, return our name
239	if (includes == null) {
240	return currentFile;
241
242	// otherwise, recurse over our includes
243	} else {
244	StringTokenizer st = new StringTokenizer(includes, ";");
245	String returnList= "";
246	while (st.hasMoreTokens()) {
247	returnList = getIncludedFiles(st.nextToken(), readFiles) + ";" + returnList;
248	}
249
250	return returnList + currentFile;
251	}
252	}
253
254	/**
255	* This simple method checks to see if a given
256	* file exists in the given list.
257	*
258	* @param file the file to check the list for
259	* @param fileList the list to check
260	*
261	* @return if the given file appeard in the list
262	*/
263	private boolean hasDuplicate(String file, String fileList) {
264	StringTokenizer st = new StringTokenizer(fileList, ";");
265	while (st.hasMoreTokens()) {
266	if (file.equals(st.nextToken())) {
267	return true;
268	}
269	}
270	return false;
271	}
272
273	/**
274	* Opens and loads the system configuration into the
275	* local reference _systemConfig
276	*/
277	private void loadSystemConfig() {
278	_logger.write(this.toString(), Logger.SYSMSG, "reloading " + _systemConfigFile);
279	// get a reference to the system config and store it
280	try {
281	// create the properties for the configuration
282	File systemConfigFile = new File(_configPath, _systemConfigFile);
283	_systemConfigHolder = new Properties();
284	_systemConfigHolder.load(new FileInputStream(systemConfigFile));
285
286	// create the servant
287	ConfigurationServant ref = new ConfigurationServant(_systemConfigHolder, _systemConfigFile, systemConfigFile.lastModified());
288	org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
289
290	// narrow it to a Configuration
291	_systemConfig = ConfigurationHelper.narrow(objRef);
292
293	} catch (Exception e) {
294	_logger.write(toString(), Logger.FATAL, "ERROR: " + e.getMessage());
295	}
296	}
297
298	/**
299	* Parses the system configuration file
300	* for group membership entries.
301	*
302	* It looks for all entries of group.<name>
303	* which contain the given source name
304	*
305	* @param source the source to find membership for
306	*
307	* @return the list of groups that this source is a member of
308	*/
309	private LinkedList getGroupMembership(String source) {
310	_logger.write(toString(), Logger.DEBUG, "searching group members for - " + source);
311	LinkedList groupMembership = new LinkedList();
312	Iterator i = new TreeSet(_systemConfigHolder.keySet()).iterator();
313	while(i.hasNext()) {
314	String key = (String) i.next();
315	if (key.startsWith("group.")) {
316	String group = _systemConfig.getProperty(key);
317	// if it is in the group
318	if (group.indexOf(source) != -1) {
319	groupMembership.add(key.substring(6));
320
321	// if there are wildcards in the group
322	} else if (group.indexOf("*") != -1) {
323	// check the wildcards apply to this srce
324	if( wildcardCheck(source, group)) {
325	groupMembership.add(key.substring(6));
326	}
327	}
328
329	}
330	}
331	return groupMembership;
332	}
333
334	/**
335	* Checks that a given string is not matched within the
336	* given list of strings. eg:<br>
337	* <br>
338	* Given "stue5de.ukc.ac.uk"<br>
339	* And "raptor.ukc.ac.uk;stue*.ukc.ac.uk<br>
340	* <br>
341	* This method would return true as there is a match
342	*
343	* @param source the string to look for
344	* @param group the group to search for a wilcard entry
345	*
346	* @return if there is a match
347	*/
348	private boolean wildcardCheck(String source, String group) {
349	boolean foundMatch = false;
350	StringTokenizer st = new StringTokenizer(group, ";");
351	// go through all the hosts in the group
352	while (st.hasMoreTokens()) {
353	String host = st.nextToken();
354	// this host has wildcards
355	if(host.indexOf("*") != -1) {
356	StringTokenizer hostst = new StringTokenizer(host, "*");
357	String part = "";
358	int index = 0;
359	// the first token will be everything at the start
360	// unless it starts with a wildcard
361	if(!host.startsWith("*")) {
362	part = hostst.nextToken();
363	if (source.startsWith(part)) {
364	foundMatch = true;
365	index = part.length();
366	}
367	// all of the start of the string is matched
368	} else {
369	foundMatch = true;
370	}
371	// if the start matched, we want to check the rest...
372	if (foundMatch) {
373	while (hostst.hasMoreTokens()) {
374	part = hostst.nextToken();
375	// if the next section can't be matched
376	// then this isn't in the source
377	if(source.substring(index).indexOf(part) == -1) {
378	foundMatch = false;
379	// we don't want to look through any more of it
380	break;
381	} else {
382	foundMatch = true;
383	index += source.substring(index).indexOf(part) + part.length();
384	}
385	}
386	// if we reach here and we've found a match
387	// we want to check that the last part
388	// of the wildcard string is the last part
389	// of the source, if it is, we break out
390	// and finish as we've found a match.
391	// if the end of the wildcard is a *, then
392	// we don't care
393	if (!host.endsWith("*") && foundMatch) {
394	if ((source.endsWith(part))) {
395	_logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
396	break;
397	// if there is no match, say so so we go round again
398	} else {
399	foundMatch = false;
400	}
401	} else if (foundMatch) {
402	_logger.write(toString(), Logger.DEBUG, "wildcard match found for - " + source + " in - " + host);
403	break;
404	}
405	}
406	}
407	}
408	return foundMatch;
409	}
410
411
412	/**
413	* Build the properties as a Configuration to be
414	* returned to the caller
415	*
416	* @param fileList the list of files to build the configuration from
417	*
418	* @return the built Configuration
419	*/
420	private Configuration buildConfiguration(String fileList) {
421	Configuration config = null;
422
423	// if there is an entry
424	if (!fileList.equals("")) {
425	try {
426
427	// build the properites here from the filelist....
428	StringTokenizer st = new StringTokenizer(fileList, ";");
429
430	// some holders for variables
431	File currentFile;
432	long lastModified = 0, newLastModified = 0;
433	Properties properties = null, prevProperties = null;
434
435	// the root of all configurations will be the system config
436	// so we need to open the properties of that
437	Properties defaultProperties = new Properties();
438
439	// This loop then iterates over the file list
440	// creates the properties to be passed to the
441	// Configuration constructor
442	while (st.hasMoreTokens()) {
443	properties = new Properties(defaultProperties);
444	currentFile = new File(_configPath, st.nextToken());
445	newLastModified = currentFile.lastModified();
446	if (newLastModified > lastModified) {
447	lastModified = newLastModified;
448	}
449	properties.load(new FileInputStream(currentFile));
450	defaultProperties = properties;
451	}
452
453	// this creates the configuration, all nice, ready to be returned
454	ConfigurationServant ref = new ConfigurationServant(properties, fileList, lastModified);
455	org.omg.CORBA.Object objRef = _refman.getRootPOA().servant_to_reference(ref);
456	config = ConfigurationHelper.narrow(objRef);
457	_logger.write(toString(), Logger.DEBUG, "returning built configuration");
458	} catch (Exception e) {
459	// not sure what to do here
460	// so we just log the error
461	_logger.write(toString(), Logger.ERROR, "ERROR - " + e);
462	}
463
464	// if there isn't an entry for the requested config
465	} else {
466	_logger.write(toString(), Logger.DEBUG, "no configured config, returning " + _systemConfigFile);
467	config = _systemConfig;
468	}
469	return config;
470	}
471
472	//---ACCESSOR/MUTATOR METHODS---
473
474	//---ATTRIBUTES---
475
476	/**
477	* This is the friendly identifier of the
478	* component this class is running in.
479	* eg, a Filter may be called "filter1",
480	* If this class does not have an owning
481	* component, a name from the configuration
482	* can be placed here. This name could also
483	* be changed to null for utility classes.
484	*/
485	private String _name = Core.NAME;
486
487	/**
488	* This holds a reference to the
489	* system logger that is being used.
490	*/
491	private Logger _logger = ReferenceManager.getInstance().getLogger();
492
493	/**
494	* A reference to the reference manager in use
495	*/
496	private ReferenceManager _refman = ReferenceManager.getInstance();
497
498	/**
499	* The root path to all configurations
500	*/
501	private String _configPath;
502
503	/**
504	* The name of the file that contains the system configuration
505	*/
506	private String _systemConfigFile;
507
508	/**
509	* An instance of the system config
510	*/
511	private Configuration _systemConfig;
512
513	/**
514	* The system config file represented by a
515	* properties object.
516	*/
517	private Properties _systemConfigHolder;
518
519	//---STATIC ATTRIBUTES---
520
521	}