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 1.25 2001/03/01 16:53:24 tdb1 Exp $
 */
public class FilterThread extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.25 $";
    
//---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.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;
        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.
            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;
            }
                               
            // XMLPacket is ok, so 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.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:	1.26
Committed:	Sat Mar 10 04:03:07 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.25:	+5 -4 lines
Log Message:	Changes due to the alterations in the XML creation code. The XMLPacketMaker now only needs to be created once, and can then be called multiple times to create XML packets. This should be more efficient in the long run.
#	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	1.24	* @author $Author: tdb1 $
22	tdb	1.26	* @version $Id: FilterThread.java,v 1.25 2001/03/01 16:53:24 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	1.26	public final String REVISION = "$Revision: 1.25 $";
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	tdb	1.19	_logger.write(toString(), Logger.SYSINIT, "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	1.26	// setup the XMLPacketMaker
57			XMLPacketMaker xmlPacketMaker = new XMLPacketMaker();
58	tdb	1.15	// get a queue for ourselves
59			int n = _queue.getQueue();
60	pjm2	1.16	// keep these out here, saves recreating the object
61	tdb	1.15	String xml = null;
62			while(true) {
63			// get a String of xml
64			try {
65			xml = (String) _queue.get(n);
66			}
67			catch (InvalidQueueException e) {
68			_logger.write(toString(), Logger.ERROR, "Queue error: "+e);
69			}
70
71			// Get a string without any null characters in it.
72			// -- maybe String.trim() would be better here ?
73			if (xml.indexOf(0) != -1) {
74			xml = xml.substring(0, xml.indexOf(0));
75			}
76			else {
77			xml = xml.substring(0, xml.length());
78			}
79	pjm2	1.16
80			// Bundle the XML all on one line (saves space and simplifies
81	tdb	1.18	// the protocol between clientinterface and client).
82	pjm2	1.16	StringTokenizer tokenizer = new StringTokenizer(new String(xml), "\n");
83			xml = "";
84			while (tokenizer.hasMoreTokens()) {
85			xml += tokenizer.nextToken();
86			}
87	tdb	1.15
88			// Use XMLPacketMaker to make an XMLPacket object.
89	tdb	1.25	XMLPacket packet = null;
90			try {
91	tdb	1.26	packet = xmlPacketMaker.createXMLPacket(xml);
92	tdb	1.25	} catch(InvalidXMLException e) {
93			_logger.write(toString(), Logger.ERROR, "Invalid XML: "+e);
94			// skip the rest of this loop iteration
95			continue;
96			}
97
98			// XMLPacket is ok, so run filters...
99			if(PluginFilterManager.getInstance().runFilters(packet)) {
100			// and pass it on...
101			_parent.receiveXML(xml);
102	tdb	1.15	}
103			else {
104	tdb	1.25	// ... or filtered it
105			_logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
106	tdb	1.15	}
107	pjm2	1.1	}
108			}
109	tdb	1.8
110			/**
111			* Overrides the {@link java.lang.Object#toString() Object.toString()}
112			* method to provide clean logging (every class should have this).
113			*
114	ajm	1.14	* This uses the uk.ac.ukc.iscream.util.NameFormat class
115			* to format the toString()
116			*
117	tdb	1.8	* @return the name of this class and its CVS revision
118			*/
119			public String toString() {
120	ajm	1.14	return FormatName.getName(
121			_name,
122			getClass().getName(),
123			REVISION);
124	tdb	1.8	}
125
126			//---PRIVATE METHODS---
127
128			//---ACCESSOR/MUTATOR METHODS---
129
130			//---ATTRIBUTES---
131
132	ajm	1.14	/**
133			* Our parent filter
134			*/
135	tdb	1.10	Filter _parent;
136	ajm	1.14
137			/**
138	tdb	1.15	* The Queue object
139	ajm	1.14	*/
140	tdb	1.15	Queue _queue;
141	ajm	1.14
142			/**
143			* This is the friendly identifier of the
144			* component this class is running in.
145			* eg, a Filter may be called "filter1",
146			* If this class does not have an owning
147			* component, a name from the configuration
148			* can be placed here. This name could also
149			* be changed to null for utility classes.
150			*/
151			private String _name = FilterMain.NAME;
152
153			/**
154			* This holds a reference to the
155			* system logger that is being used.
156			*/
157			private Logger _logger = ReferenceManager.getInstance().getLogger();
158	tdb	1.8
159			//---STATIC ATTRIBUTES---
160
161	pjm2	1.1	}