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.componentmanager.*;
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 1.17 2001/01/18 23:16:21 tdb1 Exp $
 */
public class FilterThread extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.17 $";
    
//---STATIC METHODS---

//---CONSTRUCTORS---
   
    /**
     * Constructs an instance of a FilterThread
     *
     * @param queue the Queue this filter is using
     * @param parent a CORBA reference to our parent filter
     */
    public FilterThread(Queue queue, Filter parent){
        _parent = parent;
        _queue = queue;
        _logger.write(toString(), Logger.DEBUG, "created");
    }

//---PUBLIC METHODS---

    /**
     * Runs the thread, getting data from the Queue and
     * sending it on to the parent filter.
     */
    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:	1.18
Committed:	Sun Jan 28 05:25:43 2001 UTC (23 years, 3 months ago) by tdb
Branch:	MAIN
Changes since 1.17:	+10 -8 lines
Log Message:	Some tidying up.
#	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	1.17	import uk.ac.ukc.iscream.componentmanager.*;
10	tdb	1.2	import uk.ac.ukc.iscream.filter.*;
11	ajm	1.11	import uk.ac.ukc.iscream.util.*;
12	pjm2	1.1
13	tdb	1.8	/**
14	ajm	1.14	* Handle an incoming packet as a separate thread.
15			* Passes the data through various plugins, then
16			* passes it on to the parent filter.
17	tdb	1.8	*
18	tdb	1.15	* Now grabs data from a single queue, rather than
19			* waiting to be contacted.
20			*
21	tdb	1.18	* @author $Author: tdb1 $
22			* @version $Id: FilterThread.java,v 1.17 2001/01/18 23:16:21 tdb1 Exp $
23	tdb	1.8	*/
24	tdb	1.2	public class FilterThread extends Thread{
25	pjm2	1.1
26	tdb	1.8	//---FINAL ATTRIBUTES---
27
28			/**
29			* The current CVS revision of this class
30			*/
31	tdb	1.18	public final String REVISION = "$Revision: 1.17 $";
32	tdb	1.8
33			//---STATIC METHODS---
34
35			//---CONSTRUCTORS---
36	tdb	1.15
37	ajm	1.14	/**
38	tdb	1.18	* Constructs an instance of a FilterThread
39			*
40			* @param queue the Queue this filter is using
41			* @param parent a CORBA reference to our parent filter
42	ajm	1.14	*/
43	tdb	1.15	public FilterThread(Queue queue, Filter parent){
44	tdb	1.10	_parent = parent;
45	tdb	1.15	_queue = queue;
46	ajm	1.14	_logger.write(toString(), Logger.DEBUG, "created");
47	pjm2	1.1	}
48	tdb	1.8
49			//---PUBLIC METHODS---
50
51	ajm	1.14	/**
52	tdb	1.18	* Runs the thread, getting data from the Queue and
53			* sending it on to the parent filter.
54	ajm	1.14	*/
55	pjm2	1.1	public void run(){
56	tdb	1.15	// get a queue for ourselves
57			int n = _queue.getQueue();
58	pjm2	1.16	// keep these out here, saves recreating the object
59	tdb	1.15	String xml = null;
60			while(true) {
61			// get a String of xml
62			try {
63			xml = (String) _queue.get(n);
64			}
65			catch (InvalidQueueException e) {
66			_logger.write(toString(), Logger.ERROR, "Queue error: "+e);
67			}
68
69			// Get a string without any null characters in it.
70			// -- maybe String.trim() would be better here ?
71			if (xml.indexOf(0) != -1) {
72			xml = xml.substring(0, xml.indexOf(0));
73			}
74			else {
75			xml = xml.substring(0, xml.length());
76			}
77	pjm2	1.16
78			// Bundle the XML all on one line (saves space and simplifies
79	tdb	1.18	// the protocol between clientinterface and client).
80	pjm2	1.16	StringTokenizer tokenizer = new StringTokenizer(new String(xml), "\n");
81			xml = "";
82			while (tokenizer.hasMoreTokens()) {
83			xml += tokenizer.nextToken();
84			}
85	tdb	1.15
86			// Use XMLPacketMaker to make an XMLPacket object.
87			XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
88			XMLPacket packet = xmlPacketMaker.createXMLPacket();
89
90			if(packet != null && PluginFilterManager.getInstance().runFilters(packet)) {
91			// packet is not null
92			// packet was not dropped by a plugin
93			// ... best pass it on !
94			_parent.receiveXML(xml);
95			}
96			else {
97			// either we had a null, or a plugin dropped it
98			_logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
99			}
100	pjm2	1.1	}
101			}
102	tdb	1.8
103			/**
104			* Overrides the {@link java.lang.Object#toString() Object.toString()}
105			* method to provide clean logging (every class should have this).
106			*
107	ajm	1.14	* This uses the uk.ac.ukc.iscream.util.NameFormat class
108			* to format the toString()
109			*
110	tdb	1.8	* @return the name of this class and its CVS revision
111			*/
112			public String toString() {
113	ajm	1.14	return FormatName.getName(
114			_name,
115			getClass().getName(),
116			REVISION);
117	tdb	1.8	}
118
119			//---PRIVATE METHODS---
120
121			//---ACCESSOR/MUTATOR METHODS---
122
123			//---ATTRIBUTES---
124
125	ajm	1.14	/**
126			* Our parent filter
127			*/
128	tdb	1.10	Filter _parent;
129	ajm	1.14
130			/**
131	tdb	1.15	* The Queue object
132	ajm	1.14	*/
133	tdb	1.15	Queue _queue;
134	ajm	1.14
135			/**
136			* This is the friendly identifier of the
137			* component this class is running in.
138			* eg, a Filter may be called "filter1",
139			* If this class does not have an owning
140			* component, a name from the configuration
141			* can be placed here. This name could also
142			* be changed to null for utility classes.
143			*/
144			private String _name = FilterMain.NAME;
145
146			/**
147			* This holds a reference to the
148			* system logger that is being used.
149			*/
150			private Logger _logger = ReferenceManager.getInstance().getLogger();
151	tdb	1.8
152			//---STATIC ATTRIBUTES---
153
154	pjm2	1.1	}