server/XMLReader/XMLPacketMaker.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

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

    public XMLPacketMaker () {
        // default no-args constructor.
    }

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

    public static void main(String[] args){
        if (args.length != 1) {
            System.err.println ("Usage: cmd filename");
            System.exit (1);
        }

        // Use the default (non-validating) parser
        SAXParserFactory factory = SAXParserFactory.newInstance();
        try {
            // Set up output stream
            out = new OutputStreamWriter (System.out, "UTF8");

            // Create the XMLPacket to store values in.
            packet = new XMLPacket();

            // Parse the input
            SAXParser saxParser = factory.newSAXParser();
            saxParser.parse(new File(args[0]), new XMLPacketMaker(packet));

            // Print out the entire contents of the packet's HashMap.
            System.out.println("XMLPacket contents: -");
            packet.printAll();

        } catch (Throwable t) {
            t.printStackTrace ();
        }
        System.exit (0);
    }

    static private Writer out;
    private String indentString = "    "; // Amount to indent
    private int indentLevel = 0;

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

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

    public void startDocument () throws SAXException {
        // No purpose currently.
    }

    public void endDocument () throws SAXException {
        // No purpose currently.
    }

    // 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:	1.8
Committed:	Tue Nov 14 12:23:17 2000 UTC (24 years ago) by pjm2
Branch:	MAIN
Changes since 1.7:	+23 -55 lines
Log Message:	Updated the test.xml file to contain slightly more realistic data ;-) The XMLPacketMaker main method now handles attributes within XML opening tags. Read the comments in the file to see how these are dealt with. Go on, you know you want to.
#	User	Rev	Content
1	pjm2	1.3	import java.io.*;
2			import java.util.ArrayList;
3
4			import org.xml.sax.*;
5
6	pjm2	1.7	import javax.xml.parsers.SAXParserFactory;
7			import javax.xml.parsers.ParserConfigurationException;
8			import javax.xml.parsers.SAXParser;
9	pjm2	1.3
10	pjm2	1.7	// Paul Mutton, pjm2@ukc.ac.uk
11	pjm2	1.3
12	pjm2	1.7	// XMLPacketMaker - Creates an XMLPacket object.
13	pjm2	1.3	public class XMLPacketMaker extends HandlerBase {
14	pjm2	1.5
15			public XMLPacketMaker () {
16			// default no-args constructor.
17			}
18
19			// Constructor for accepting a reference to an XMLPacket
20			public XMLPacketMaker (XMLPacket packet) {
21			this.packet = packet;
22			}
23
24	pjm2	1.3	public static void main(String[] args){
25			if (args.length != 1) {
26			System.err.println ("Usage: cmd filename");
27			System.exit (1);
28			}
29
30			// Use the default (non-validating) parser
31			SAXParserFactory factory = SAXParserFactory.newInstance();
32			try {
33			// Set up output stream
34			out = new OutputStreamWriter (System.out, "UTF8");
35
36	pjm2	1.5	// Create the XMLPacket to store values in.
37			packet = new XMLPacket();
38
39	pjm2	1.3	// Parse the input
40			SAXParser saxParser = factory.newSAXParser();
41	pjm2	1.5	saxParser.parse(new File(args[0]), new XMLPacketMaker(packet));
42
43	pjm2	1.8	// Print out the entire contents of the packet's HashMap.
44			System.out.println("XMLPacket contents: -");
45	pjm2	1.7	packet.printAll();
46	pjm2	1.3
47			} catch (Throwable t) {
48			t.printStackTrace ();
49			}
50			System.exit (0);
51			}
52
53			static private Writer out;
54			private String indentString = " "; // Amount to indent
55			private int indentLevel = 0;
56
57	pjm2	1.4	// For storing the tag heirarchy.
58	pjm2	1.3	private ArrayList tagList = new ArrayList();
59	pjm2	1.5	static private XMLPacket packet = null;
60	pjm2	1.3
61			//===========================================================
62			// SAX DocumentHandler methods
63			//===========================================================
64
65			public void startDocument () throws SAXException {
66	pjm2	1.8	// No purpose currently.
67	pjm2	1.3	}
68
69			public void endDocument () throws SAXException {
70	pjm2	1.8	// No purpose currently.
71	pjm2	1.3	}
72
73	pjm2	1.8	// Add each tag's attribute to the XMLPacket.
74			// Note that all attributes within an opening tag are
75			// stored as "someroot.sometag.attributes.attribute_name"
76			// E.g. If <packet> is the root node, then:
77			// <packet machine_name="raptor">
78			// is stored as:
79			// "packet.attributes.machine_name"
80			// within the XMLPacket.
81	pjm2	1.3	public void startElement (String name, AttributeList attrs) throws SAXException {
82			indentLevel++;
83	pjm2	1.5	tagList.add(name);
84	pjm2	1.3	if (attrs != null) {
85			for (int i = 0; i < attrs.getLength (); i++) {
86	pjm2	1.8	packet.addParam(getPath()+".attributes."+attrs.getName(i), attrs.getValue(i));
87	pjm2	1.3	}
88			}
89			}
90
91	pjm2	1.8	// When an XML element is finished with, we must remove
92			// the tag name from the tagList and decrement the indent
93			// level.
94	pjm2	1.3	public void endElement (String name) throws SAXException {
95	pjm2	1.5	tagList.remove(tagList.size()-1);
96	pjm2	1.3	indentLevel--;
97			}
98
99	pjm2	1.8	// Any text falling within a pair of terminal tags must
100			// be added to the XMLPacket. Trim leading and trailing
101			// spaces and do not bother to add if there is no data
102			// specified within the tags.
103	pjm2	1.3	public void characters (char[] buf, int offset, int len) throws SAXException {
104			String s = new String(buf, offset, len);
105	pjm2	1.5	if (!s.trim().equals("")) {
106	pjm2	1.6	packet.addParam(getPath(), s);
107	pjm2	1.5	}
108	pjm2	1.3	}
109
110	pjm2	1.8
111	pjm2	1.3	//===========================================================
112			// Helpers ...
113			//===========================================================
114	pjm2	1.8
115	pjm2	1.6
116	pjm2	1.7	// Return the heirarchical string to be used as a key value
117			// in the XMLPacket.
118	pjm2	1.6	private String getPath () {
119			String path = (String)tagList.get(0);
120			if (tagList.size() > 0) {
121			for (int i = 1 ; i < tagList.size() ; i++) {
122			path = path + "." + (String)tagList.get(i);
123			}
124			}
125			return path;
126	pjm2	1.3	}
127	pjm2	1.8
128	pjm2	1.3	}