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: pjm2 $
 * @version $Id: FilterThread.java,v 1.16 2001/01/15 10:09:49 pjm2 Exp $
 */
public class FilterThread extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.16 $";
    
//---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:	1.17
Committed:	Thu Jan 18 23:16:21 2001 UTC (23 years, 4 months ago) by tdb
Branch:	MAIN
Changes since 1.16:	+4 -3 lines
Log Message:	Changes to reflect move of Component, ComponentStartException, and the ReferenceManager from util to componentmanager.
#	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	1.17	* @author $Author: pjm2 $
22			* @version $Id: FilterThread.java,v 1.16 2001/01/15 10:09:49 pjm2 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	1.17	public final String REVISION = "$Revision: 1.16 $";
32	tdb	1.8
33			//---STATIC METHODS---
34
35			//---CONSTRUCTORS---
36	tdb	1.15
37	ajm	1.14	/**
38	tdb	1.15	* Class constructor.
39	ajm	1.14	*/
40	tdb	1.15	public FilterThread(Queue queue, Filter parent){
41	tdb	1.10	_parent = parent;
42	tdb	1.15	_queue = queue;
43	ajm	1.14	_logger.write(toString(), Logger.DEBUG, "created");
44	pjm2	1.1	}
45	tdb	1.8
46			//---PUBLIC METHODS---
47
48	ajm	1.14	/**
49			* Runs the thread
50			*/
51	pjm2	1.1	public void run(){
52	tdb	1.15	// get a queue for ourselves
53			int n = _queue.getQueue();
54	pjm2	1.16	// keep these out here, saves recreating the object
55	tdb	1.15	String xml = null;
56			while(true) {
57			// get a String of xml
58			try {
59			xml = (String) _queue.get(n);
60			}
61			catch (InvalidQueueException e) {
62			_logger.write(toString(), Logger.ERROR, "Queue error: "+e);
63			}
64
65			// Get a string without any null characters in it.
66			// -- maybe String.trim() would be better here ?
67			if (xml.indexOf(0) != -1) {
68			xml = xml.substring(0, xml.indexOf(0));
69			}
70			else {
71			xml = xml.substring(0, xml.length());
72			}
73	pjm2	1.16
74
75			// Bundle the XML all on one line (saves space and simplifies
76			// the protocol between clientinterface and client.
77			StringTokenizer tokenizer = new StringTokenizer(new String(xml), "\n");
78			xml = "";
79			while (tokenizer.hasMoreTokens()) {
80			xml += tokenizer.nextToken();
81			}
82
83	tdb	1.15
84			// Use XMLPacketMaker to make an XMLPacket object.
85			XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
86			XMLPacket packet = xmlPacketMaker.createXMLPacket();
87
88			if(packet != null && PluginFilterManager.getInstance().runFilters(packet)) {
89			// packet is not null
90			// packet was not dropped by a plugin
91			// ... best pass it on !
92			_parent.receiveXML(xml);
93			}
94			else {
95			// either we had a null, or a plugin dropped it
96			_logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
97			}
98	pjm2	1.1	}
99			}
100	tdb	1.8
101			/**
102			* Overrides the {@link java.lang.Object#toString() Object.toString()}
103			* method to provide clean logging (every class should have this).
104			*
105	ajm	1.14	* This uses the uk.ac.ukc.iscream.util.NameFormat class
106			* to format the toString()
107			*
108	tdb	1.8	* @return the name of this class and its CVS revision
109			*/
110			public String toString() {
111	ajm	1.14	return FormatName.getName(
112			_name,
113			getClass().getName(),
114			REVISION);
115	tdb	1.8	}
116
117			//---PRIVATE METHODS---
118
119			//---ACCESSOR/MUTATOR METHODS---
120
121			//---ATTRIBUTES---
122
123	ajm	1.14	/**
124			* Our parent filter
125			*/
126	tdb	1.10	Filter _parent;
127	ajm	1.14
128			/**
129	tdb	1.15	* The Queue object
130	ajm	1.14	*/
131	tdb	1.15	Queue _queue;
132	ajm	1.14
133			/**
134			* This is the friendly identifier of the
135			* component this class is running in.
136			* eg, a Filter may be called "filter1",
137			* If this class does not have an owning
138			* component, a name from the configuration
139			* can be placed here. This name could also
140			* be changed to null for utility classes.
141			*/
142			private String _name = FilterMain.NAME;
143
144			/**
145			* This holds a reference to the
146			* system logger that is being used.
147			*/
148			private Logger _logger = ReferenceManager.getInstance().getLogger();
149	tdb	1.8
150			//---STATIC ATTRIBUTES---
151
152	pjm2	1.1	}