server/XMLReader/XMLPacketParser.java

import java.io.*;
import java.util.ArrayList;

import org.xml.sax.*;

import javax.xml.parsers.SAXParserFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;

// Paul Mutton, pjm2@ukc.ac.uk

// XMLPacketParser - Creates an XMLPacket object.
public class XMLPacketParser extends HandlerBase {

    // No-args constructor.  Generally not used.
    public XMLPacketParser () {
        this.packet = new XMLPacket();
    }

    // Constructor for accepting a reference to an XMLPacket
    public XMLPacketParser (XMLPacket packet) {
        this.packet = packet;
    }

    // Accessor to the XMLPacket.
    public XMLPacket getXMLPacket() {
        return packet;
    }

    private int indentLevel = 0;

    // For storing the tag heirarchy.
    private ArrayList tagList = new ArrayList();
    private XMLPacket packet;

    //===========================================================
    // SAX DocumentHandler methods
    //===========================================================

    public void startDocument () throws SAXException {
        System.out.println("XMLPacketParser - Starting parse process...");
    }

    public void endDocument () throws SAXException {
        System.out.println("XMLPacketParser - I just finished parsing an XML String.");
    }

    // Add each tag's attribute to the XMLPacket.
    // Note that all attributes within an opening tag are
    // stored as "someroot.sometag.attributes.attribute_name"
    // E.g. If <packet> is the root node, then:
    //     <packet machine_name="raptor">
    // is stored as:
    //     "packet.attributes.machine_name"
    // within the XMLPacket.
    public void startElement (String name, AttributeList attrs) throws SAXException {
        indentLevel++;
        tagList.add(name);
        if (attrs != null) {
            for (int i = 0; i < attrs.getLength (); i++) {
                packet.addParam(getPath()+".attributes."+attrs.getName(i), attrs.getValue(i));
            }
        }
    }

    // When an XML element is finished with, we must remove
    // the tag name from the tagList and decrement the indent
    // level.
    public void endElement (String name) throws SAXException {
        tagList.remove(tagList.size()-1);    
        indentLevel--;
    }

    // Any text falling within a pair of terminal tags must
    // be added to the XMLPacket.  Trim leading and trailing
    // spaces and do not bother to add if there is no data
    // specified within the tags.
    public void characters (char[] buf, int offset, int len) throws SAXException {
        String s = new String(buf, offset, len);
        if (!s.trim().equals("")) {
            packet.addParam(getPath(), s);
        }
    }


    //===========================================================
    // Helpers ...
    //===========================================================
    
    
    // Return the heirarchical string to be used as a key value
    // in the XMLPacket.
    private String getPath () {
        String path = (String)tagList.get(0);
        if (tagList.size() > 0) {
            for (int i = 1 ; i < tagList.size() ; i++) {
                path = path + "." + (String)tagList.get(i);
            }
        }
        return path;
    }
    
}
Revision:	1.2
Committed:	Fri Nov 17 12:16:39 2000 UTC (23 years, 5 months ago) by pjm2
Branch:	MAIN
Changes since 1.1:	+2 -2 lines
Log Message:	Changed a lot of parts of UDPReader, UDPReaderThread, XMLPacketMaker, XMLPacketParser and XMLSender so that they all work together. XMLSender is just a summy program to send UDP data to the UDPReader.
#	User	Rev	Content
1	pjm2	1.1	import java.io.*;
2			import java.util.ArrayList;
3
4			import org.xml.sax.*;
5
6			import javax.xml.parsers.SAXParserFactory;
7			import javax.xml.parsers.ParserConfigurationException;
8			import javax.xml.parsers.SAXParser;
9
10			// Paul Mutton, pjm2@ukc.ac.uk
11
12			// XMLPacketParser - Creates an XMLPacket object.
13			public class XMLPacketParser extends HandlerBase {
14
15			// No-args constructor. Generally not used.
16			public XMLPacketParser () {
17			this.packet = new XMLPacket();
18			}
19
20			// Constructor for accepting a reference to an XMLPacket
21			public XMLPacketParser (XMLPacket packet) {
22			this.packet = packet;
23			}
24
25			// Accessor to the XMLPacket.
26			public XMLPacket getXMLPacket() {
27			return packet;
28			}
29
30			private int indentLevel = 0;
31
32			// For storing the tag heirarchy.
33			private ArrayList tagList = new ArrayList();
34			private XMLPacket packet;
35
36			//===========================================================
37			// SAX DocumentHandler methods
38			//===========================================================
39
40			public void startDocument () throws SAXException {
41	pjm2	1.2	System.out.println("XMLPacketParser - Starting parse process...");
42	pjm2	1.1	}
43
44			public void endDocument () throws SAXException {
45	pjm2	1.2	System.out.println("XMLPacketParser - I just finished parsing an XML String.");
46	pjm2	1.1	}
47
48			// Add each tag's attribute to the XMLPacket.
49			// Note that all attributes within an opening tag are
50			// stored as "someroot.sometag.attributes.attribute_name"
51			// E.g. If <packet> is the root node, then:
52			// <packet machine_name="raptor">
53			// is stored as:
54			// "packet.attributes.machine_name"
55			// within the XMLPacket.
56			public void startElement (String name, AttributeList attrs) throws SAXException {
57			indentLevel++;
58			tagList.add(name);
59			if (attrs != null) {
60			for (int i = 0; i < attrs.getLength (); i++) {
61			packet.addParam(getPath()+".attributes."+attrs.getName(i), attrs.getValue(i));
62			}
63			}
64			}
65
66			// When an XML element is finished with, we must remove
67			// the tag name from the tagList and decrement the indent
68			// level.
69			public void endElement (String name) throws SAXException {
70			tagList.remove(tagList.size()-1);
71			indentLevel--;
72			}
73
74			// Any text falling within a pair of terminal tags must
75			// be added to the XMLPacket. Trim leading and trailing
76			// spaces and do not bother to add if there is no data
77			// specified within the tags.
78			public void characters (char[] buf, int offset, int len) throws SAXException {
79			String s = new String(buf, offset, len);
80			if (!s.trim().equals("")) {
81			packet.addParam(getPath(), s);
82			}
83			}
84
85
86			//===========================================================
87			// Helpers ...
88			//===========================================================
89
90
91			// Return the heirarchical string to be used as a key value
92			// in the XMLPacket.
93			private String getPath () {
94			String path = (String)tagList.get(0);
95			if (tagList.size() > 0) {
96			for (int i = 1 ; i < tagList.size() ; i++) {
97			path = path + "." + (String)tagList.get(i);
98			}
99			}
100			return path;
101			}
102
103			}