server/filter/FilterThread.java

//---PACKAGE DECLARATION---
package uk.ac.ukc.iscream.filter;

//---IMPORTS---
import java.io.*;
import java.net.*;
import java.util.*;
import uk.ac.ukc.iscream.core.*;
import uk.ac.ukc.iscream.filter.*;
import uk.ac.ukc.iscream.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: tdb1 $
 * @version $Id: FilterThread.java,v 1.15 2001/01/12 00:45:25 tdb1 Exp $
 */
public class FilterThread extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.15 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
   
    /**
     * Class constructor.
     */
    public FilterThread(Queue queue, Filter parent){
        _parent = parent;
        _queue = queue;
        _logger.write(toString(), Logger.DEBUG, "created");
    }

//---PUBLIC METHODS---

    /**
     * Runs the thread
     */
    public void run(){
        // get a queue for ourselves
        int n = _queue.getQueue();
        // keep these out here, saves recreating the object
        String xml = 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));
            }
            else {
                xml = xml.substring(0, xml.length());
            }
            
            
            // 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.
            XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
            XMLPacket packet = xmlPacketMaker.createXMLPacket();
                   
            if(packet != null && PluginFilterManager.getInstance().runFilters(packet)) {
                // packet is not null
                // packet was not dropped by a plugin
                // ... best pass it on !
                _parent.receiveXML(xml);
            }
            else {
                // either we had a null, or a plugin dropped 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.ac.ukc.iscream.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---

    /**
     * Our parent filter
     */
    Filter _parent;
    
    /**
     * 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();

//---STATIC ATTRIBUTES---

}
Revision:	1.16
Committed:	Mon Jan 15 10:09:49 2001 UTC (23 years, 4 months ago) by pjm2
Branch:	MAIN
Changes since 1.15:	+14 -4 lines
Log Message:	Each XML String now has linefeed characters removed from it. This results in a simplified protocol between the clientinterface and client, as well as potentially reducing the size of each XML String.
#	User	Rev	Content
1	tdb	1.8	//---PACKAGE DECLARATION---
2			package uk.ac.ukc.iscream.filter;
3
4			//---IMPORTS---
5	pjm2	1.1	import java.io.*;
6			import java.net.*;
7			import java.util.*;
8	pjm2	1.6	import uk.ac.ukc.iscream.core.*;
9	tdb	1.2	import uk.ac.ukc.iscream.filter.*;
10	ajm	1.11	import uk.ac.ukc.iscream.util.*;
11	pjm2	1.1
12	tdb	1.8	/**
13	ajm	1.14	* Handle an incoming packet as a separate thread.
14			* Passes the data through various plugins, then
15			* passes it on to the parent filter.
16	tdb	1.8	*
17	tdb	1.15	* Now grabs data from a single queue, rather than
18			* waiting to be contacted.
19			*
20	pjm2	1.16	* @author $Author: tdb1 $
21			* @version $Id: FilterThread.java,v 1.15 2001/01/12 00:45:25 tdb1 Exp $
22	tdb	1.8	*/
23	tdb	1.2	public class FilterThread extends Thread{
24	pjm2	1.1
25	tdb	1.8	//---FINAL ATTRIBUTES---
26
27			/**
28			* The current CVS revision of this class
29			*/
30	pjm2	1.16	public final String REVISION = "$Revision: 1.15 $";
31	tdb	1.8
32			//---STATIC METHODS---
33
34			//---CONSTRUCTORS---
35	tdb	1.15
36	ajm	1.14	/**
37	tdb	1.15	* Class constructor.
38	ajm	1.14	*/
39	tdb	1.15	public FilterThread(Queue queue, Filter parent){
40	tdb	1.10	_parent = parent;
41	tdb	1.15	_queue = queue;
42	ajm	1.14	_logger.write(toString(), Logger.DEBUG, "created");
43	pjm2	1.1	}
44	tdb	1.8
45			//---PUBLIC METHODS---
46
47	ajm	1.14	/**
48			* Runs the thread
49			*/
50	pjm2	1.1	public void run(){
51	tdb	1.15	// get a queue for ourselves
52			int n = _queue.getQueue();
53	pjm2	1.16	// keep these out here, saves recreating the object
54	tdb	1.15	String xml = null;
55			while(true) {
56			// get a String of xml
57			try {
58			xml = (String) _queue.get(n);
59			}
60			catch (InvalidQueueException e) {
61			_logger.write(toString(), Logger.ERROR, "Queue error: "+e);
62			}
63
64			// Get a string without any null characters in it.
65			// -- maybe String.trim() would be better here ?
66			if (xml.indexOf(0) != -1) {
67			xml = xml.substring(0, xml.indexOf(0));
68			}
69			else {
70			xml = xml.substring(0, xml.length());
71			}
72	pjm2	1.16
73
74			// Bundle the XML all on one line (saves space and simplifies
75			// the protocol between clientinterface and client.
76			StringTokenizer tokenizer = new StringTokenizer(new String(xml), "\n");
77			xml = "";
78			while (tokenizer.hasMoreTokens()) {
79			xml += tokenizer.nextToken();
80			}
81
82	tdb	1.15
83			// Use XMLPacketMaker to make an XMLPacket object.
84			XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
85			XMLPacket packet = xmlPacketMaker.createXMLPacket();
86
87			if(packet != null && PluginFilterManager.getInstance().runFilters(packet)) {
88			// packet is not null
89			// packet was not dropped by a plugin
90			// ... best pass it on !
91			_parent.receiveXML(xml);
92			}
93			else {
94			// either we had a null, or a plugin dropped it
95			_logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
96			}
97	pjm2	1.1	}
98			}
99	tdb	1.8
100			/**
101			* Overrides the {@link java.lang.Object#toString() Object.toString()}
102			* method to provide clean logging (every class should have this).
103			*
104	ajm	1.14	* This uses the uk.ac.ukc.iscream.util.NameFormat class
105			* to format the toString()
106			*
107	tdb	1.8	* @return the name of this class and its CVS revision
108			*/
109			public String toString() {
110	ajm	1.14	return FormatName.getName(
111			_name,
112			getClass().getName(),
113			REVISION);
114	tdb	1.8	}
115
116			//---PRIVATE METHODS---
117
118			//---ACCESSOR/MUTATOR METHODS---
119
120			//---ATTRIBUTES---
121
122	ajm	1.14	/**
123			* Our parent filter
124			*/
125	tdb	1.10	Filter _parent;
126	ajm	1.14
127			/**
128	tdb	1.15	* The Queue object
129	ajm	1.14	*/
130	tdb	1.15	Queue _queue;
131	ajm	1.14
132			/**
133			* This is the friendly identifier of the
134			* component this class is running in.
135			* eg, a Filter may be called "filter1",
136			* If this class does not have an owning
137			* component, a name from the configuration
138			* can be placed here. This name could also
139			* be changed to null for utility classes.
140			*/
141			private String _name = FilterMain.NAME;
142
143			/**
144			* This holds a reference to the
145			* system logger that is being used.
146			*/
147			private Logger _logger = ReferenceManager.getInstance().getLogger();
148	tdb	1.8
149			//---STATIC ATTRIBUTES---
150
151	pjm2	1.1	}