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 1.24 2001/02/12 00:45:57 tdb1 Exp $
 */
public class FilterThread extends Thread{

//---FINAL ATTRIBUTES---

    /**
     * The current CVS revision of this class
     */
    public final String REVISION = "$Revision: 1.24 $";
    
//---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(){
        // 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 {
                XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
                packet = xmlPacketMaker.createXMLPacket();
            } 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:	1.25
Committed:	Thu Mar 1 16:53:24 2001 UTC (23 years, 2 months ago) by tdb
Branch:	MAIN
Changes since 1.24:	+18 -18 lines
Log Message:	Added a try catch section for creating the XMLPacket.
#	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	1.25	* @version $Id: FilterThread.java,v 1.24 2001/02/12 00:45:57 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	1.25	public final String REVISION = "$Revision: 1.24 $";
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	1.15	// 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	tdb	1.25	XMLPacket packet = null;
88			try {
89			XMLPacketMaker xmlPacketMaker = new XMLPacketMaker(xml);
90			packet = xmlPacketMaker.createXMLPacket();
91			} catch(InvalidXMLException e) {
92			_logger.write(toString(), Logger.ERROR, "Invalid XML: "+e);
93			// skip the rest of this loop iteration
94			continue;
95			}
96
97			// XMLPacket is ok, so run filters...
98			if(PluginFilterManager.getInstance().runFilters(packet)) {
99			// and pass it on...
100			_parent.receiveXML(xml);
101	tdb	1.15	}
102			else {
103	tdb	1.25	// ... or filtered it
104			_logger.write(toString(), Logger.DEBUG, "An XML packet was sucessfully filtered from the system.");
105	tdb	1.15	}
106	pjm2	1.1	}
107			}
108	tdb	1.8
109			/**
110			* Overrides the {@link java.lang.Object#toString() Object.toString()}
111			* method to provide clean logging (every class should have this).
112			*
113	ajm	1.14	* This uses the uk.ac.ukc.iscream.util.NameFormat class
114			* to format the toString()
115			*
116	tdb	1.8	* @return the name of this class and its CVS revision
117			*/
118			public String toString() {
119	ajm	1.14	return FormatName.getName(
120			_name,
121			getClass().getName(),
122			REVISION);
123	tdb	1.8	}
124
125			//---PRIVATE METHODS---
126
127			//---ACCESSOR/MUTATOR METHODS---
128
129			//---ATTRIBUTES---
130
131	ajm	1.14	/**
132			* Our parent filter
133			*/
134	tdb	1.10	Filter _parent;
135	ajm	1.14
136			/**
137	tdb	1.15	* The Queue object
138	ajm	1.14	*/
139	tdb	1.15	Queue _queue;
140	ajm	1.14
141			/**
142			* This is the friendly identifier of the
143			* component this class is running in.
144			* eg, a Filter may be called "filter1",
145			* If this class does not have an owning
146			* component, a name from the configuration
147			* can be placed here. This name could also
148			* be changed to null for utility classes.
149			*/
150			private String _name = FilterMain.NAME;
151
152			/**
153			* This holds a reference to the
154			* system logger that is being used.
155			*/
156			private Logger _logger = ReferenceManager.getInstance().getLogger();
157	tdb	1.8
158			//---STATIC ATTRIBUTES---
159
160	pjm2	1.1	}