server/filter/FilterThread.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.server.filter;

//---IMPORTS---
import java.io.*;
import java.net.*;
import java.util.*;
import uk.org.iscream.cms.server.core.*;
import uk.org.iscream.cms.server.componentmanager.*;
import uk.org.iscream.cms.server.filter.*;
import uk.org.iscream.cms.server.util.*;

/**
 * Handle an incoming packet as a separate thread.
 * Passes the data through various plugins, then 
 * passes it on to the parent filter.
 *
 * Now grabs data from a single queue, rather than
 * waiting to be contacted.
 *
 * @author  $Author: tdb $
 * @version $Id: FilterThread.java,v 1.35 2002/05/18 18:16:02 tdb Exp $
 */
public class FilterThread extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.35 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
   
    /**
     * Constructs an instance of a FilterThread
     *
     * @param queue the Queue this filter is using
     */
    public FilterThread(Queue queue){
        // set the Thread name
        setName("filter.FilterThread");
        
        _queue = queue;
        _logger.write(toString(), Logger.SYSINIT, "created");
    }

//---PUBLIC METHODS---

    /**
     * Runs the thread, getting data from the Queue and
     * sending it on to the parent filter.
     */
    public void run(){
        // setup the XMLPacketMaker
        XMLPacketMaker xmlPacketMaker = new XMLPacketMaker();
        // get a queue for ourselves
        int n = _queue.getQueue();
        // keep these out here, saves recreating the object
        String xml = null;
        String parentFilterName = "";
        Filter parent = null;
        while(true) {
            // get a String of xml
            try {
                xml = (String) _queue.get(n);
            }
            catch (InvalidQueueException e) {
                _logger.write(toString(), Logger.ERROR, "Queue error: "+e);
            }
            
            // Get a string without any null characters in it.
            //  -- maybe String.trim() would be better here ?
            if (xml.indexOf(0) != -1) {
                xml = xml.substring(0, xml.indexOf(0));
            }
            
            // Bundle the XML all on one line (saves space and simplifies
            // the protocol between clientinterface and client).
            StringTokenizer tokenizer = new StringTokenizer(new String(xml), "\n");
            xml = "";
            while (tokenizer.hasMoreTokens()) {
                xml += tokenizer.nextToken();
            }
            
            // Use XMLPacketMaker to make an XMLPacket object.
            XMLPacket packet = null;
            try {
                packet = xmlPacketMaker.createXMLPacket(xml);
            } catch(InvalidXMLException e) {
                _logger.write(toString(), Logger.ERROR, "Invalid XML: "+e);
                // skip the rest of this loop iteration
                continue;
            }
            
            // get parent
            try {
                String newParent = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.parentFilter");
                if(!parentFilterName.equals(newParent)) {
                    parentFilterName = newParent;
                    parent = FilterHelper.narrow(_refman.getCORBARef("iscream.Filter." + parentFilterName));
                    _logger.write(toString(), Logger.DEBUG, "Parent filter changed to: "+parentFilterName);
                }
            } catch (PropertyNotFoundException e) {
                continue;
            }
                    
            // XMLPacket is ok, run filters...
            if(PluginFilterManager.getInstance().runFilters(packet)) {
                // and pass it on...
                parent.receiveXML(xml);
            }
            else {
                // ... or filtered it
                _logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
            }
        }
    }

    /**
     * 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.cms.server.util.NameFormat 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---

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

//---ATTRIBUTES---
    
    /**
     * The Queue object
     */
    Queue _queue;
    
    /**
     * 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 = FilterMain.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();

//---STATIC ATTRIBUTES---

}
Revision:	1.36
Committed:	Tue May 21 16:47:17 2002 UTC (22 years ago) by tdb
Branch:	MAIN
Changes since 1.35:	+3 -2 lines
Log Message:	Added URL to GPL headers.
#	User	Rev	Content
1	tdb	1.35	/*
2			* i-scream central monitoring system
3	tdb	1.36	* http://www.i-scream.org.uk
4	tdb	1.35	* 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	1.8	//---PACKAGE DECLARATION---
22	tdb	1.32	package uk.org.iscream.cms.server.filter;
23	tdb	1.8
24			//---IMPORTS---
25	pjm2	1.1	import java.io.*;
26			import java.net.*;
27			import java.util.*;
28	tdb	1.32	import uk.org.iscream.cms.server.core.*;
29			import uk.org.iscream.cms.server.componentmanager.*;
30			import uk.org.iscream.cms.server.filter.*;
31			import uk.org.iscream.cms.server.util.*;
32	pjm2	1.1
33	tdb	1.8	/**
34	ajm	1.14	* Handle an incoming packet as a separate thread.
35			* Passes the data through various plugins, then
36			* passes it on to the parent filter.
37	tdb	1.8	*
38	tdb	1.15	* Now grabs data from a single queue, rather than
39			* waiting to be contacted.
40			*
41	tdb	1.33	* @author $Author: tdb $
42	tdb	1.36	* @version $Id: FilterThread.java,v 1.35 2002/05/18 18:16:02 tdb Exp $
43	tdb	1.8	*/
44	tdb	1.2	public class FilterThread extends Thread{
45	pjm2	1.1
46	tdb	1.8	//---FINAL ATTRIBUTES---
47
48			/**
49			* The current CVS revision of this class
50			*/
51	tdb	1.36	public final String REVISION = "$Revision: 1.35 $";
52	tdb	1.8
53			//---STATIC METHODS---
54
55			//---CONSTRUCTORS---
56	tdb	1.15
57	ajm	1.14	/**
58	tdb	1.18	* Constructs an instance of a FilterThread
59			*
60			* @param queue the Queue this filter is using
61	ajm	1.14	*/
62	tdb	1.28	public FilterThread(Queue queue){
63	tdb	1.27	// set the Thread name
64			setName("filter.FilterThread");
65
66	tdb	1.15	_queue = queue;
67	tdb	1.19	_logger.write(toString(), Logger.SYSINIT, "created");
68	pjm2	1.1	}
69	tdb	1.8
70			//---PUBLIC METHODS---
71
72	ajm	1.14	/**
73	tdb	1.18	* Runs the thread, getting data from the Queue and
74			* sending it on to the parent filter.
75	ajm	1.14	*/
76	pjm2	1.1	public void run(){
77	tdb	1.26	// setup the XMLPacketMaker
78			XMLPacketMaker xmlPacketMaker = new XMLPacketMaker();
79	tdb	1.15	// get a queue for ourselves
80			int n = _queue.getQueue();
81	pjm2	1.16	// keep these out here, saves recreating the object
82	tdb	1.15	String xml = null;
83	tdb	1.30	String parentFilterName = "";
84			Filter parent = null;
85	tdb	1.15	while(true) {
86			// get a String of xml
87			try {
88			xml = (String) _queue.get(n);
89			}
90			catch (InvalidQueueException e) {
91			_logger.write(toString(), Logger.ERROR, "Queue error: "+e);
92			}
93
94			// Get a string without any null characters in it.
95			// -- maybe String.trim() would be better here ?
96			if (xml.indexOf(0) != -1) {
97			xml = xml.substring(0, xml.indexOf(0));
98			}
99	pjm2	1.16
100			// Bundle the XML all on one line (saves space and simplifies
101	tdb	1.18	// the protocol between clientinterface and client).
102	pjm2	1.16	StringTokenizer tokenizer = new StringTokenizer(new String(xml), "\n");
103			xml = "";
104			while (tokenizer.hasMoreTokens()) {
105			xml += tokenizer.nextToken();
106			}
107	tdb	1.15
108			// Use XMLPacketMaker to make an XMLPacket object.
109	tdb	1.25	XMLPacket packet = null;
110			try {
111	tdb	1.26	packet = xmlPacketMaker.createXMLPacket(xml);
112	tdb	1.25	} catch(InvalidXMLException e) {
113			_logger.write(toString(), Logger.ERROR, "Invalid XML: "+e);
114			// skip the rest of this loop iteration
115			continue;
116			}
117	tdb	1.28
118			// get parent
119			try {
120	tdb	1.33	String newParent = ConfigurationProxy.getInstance().getProperty("Filter." + FilterMain.NAME, "Filter.parentFilter");
121	tdb	1.30	if(!parentFilterName.equals(newParent)) {
122	tdb	1.31	parentFilterName = newParent;
123	tdb	1.30	parent = FilterHelper.narrow(_refman.getCORBARef("iscream.Filter." + parentFilterName));
124			_logger.write(toString(), Logger.DEBUG, "Parent filter changed to: "+parentFilterName);
125			}
126	tdb	1.28	} catch (PropertyNotFoundException e) {
127			continue;
128			}
129
130			// XMLPacket is ok, run filters...
131	tdb	1.25	if(PluginFilterManager.getInstance().runFilters(packet)) {
132			// and pass it on...
133	tdb	1.28	parent.receiveXML(xml);
134	tdb	1.15	}
135			else {
136	tdb	1.25	// ... or filtered it
137			_logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
138	tdb	1.15	}
139	pjm2	1.1	}
140			}
141	tdb	1.8
142			/**
143			* Overrides the {@link java.lang.Object#toString() Object.toString()}
144			* method to provide clean logging (every class should have this).
145			*
146	tdb	1.32	* This uses the uk.org.iscream.cms.server.util.NameFormat class
147	ajm	1.14	* to format the toString()
148			*
149	tdb	1.8	* @return the name of this class and its CVS revision
150			*/
151			public String toString() {
152	ajm	1.14	return FormatName.getName(
153			_name,
154			getClass().getName(),
155			REVISION);
156	tdb	1.8	}
157
158			//---PRIVATE METHODS---
159
160			//---ACCESSOR/MUTATOR METHODS---
161
162			//---ATTRIBUTES---
163	ajm	1.14
164			/**
165	tdb	1.15	* The Queue object
166	ajm	1.14	*/
167	tdb	1.15	Queue _queue;
168	ajm	1.14
169			/**
170			* This is the friendly identifier of the
171			* component this class is running in.
172			* eg, a Filter may be called "filter1",
173			* If this class does not have an owning
174			* component, a name from the configuration
175			* can be placed here. This name could also
176			* be changed to null for utility classes.
177			*/
178			private String _name = FilterMain.NAME;
179
180			/**
181			* This holds a reference to the
182			* system logger that is being used.
183			*/
184			private Logger _logger = ReferenceManager.getInstance().getLogger();
185	tdb	1.28
186			/**
187			* A reference to the reference manager in use
188			*/
189			private ReferenceManager _refman = ReferenceManager.getInstance();
190	tdb	1.8
191			//---STATIC ATTRIBUTES---
192
193	pjm2	1.1	}