Kxml解析xml总结

要使用kxml，你必须首先得到一个XmlParser实例，它用Reader作为构造器的参数：
try {
    Reader    r = .....;
    XmlParser parser = new XmlParser( r );
}
catch( java.io.IOException e ){
    // handle exception....
}

如果你的xml文档存储在String内的话你可以使用ByteArrayInputStream和InputStreamReader：
String    xml = "<a>some xml</a>";
ByteArrayInputStream bin =
            new ByteArrayInputStream( xml.getBytes() );
XmlParser parser = new XmlParser( new InputStreamReader( bin ) );
当从网上接收数据的时候可以这样：
HttpConnection    conn = .....;
InputStreamReader doc =
         new InputStreamReader( conn.openInputStream() );
XmlParser parser = new XmlParser( doc );
得到parser实例后我们就可以调用read方法进行解析了，read方法会返回一个ParseEvent,通过判断他的类型我们就可以解析xml了。
try {
    boolean keepParsing = true;
       
    while( keepParsing ){
        ParseEvent event = parser.read();
 
        switch( event.getType() ){
            case Xml.START_TAG:
                ..... // handle start of an XML tag
                break;
            case Xml.END_TAG:
                ..... // handle end of an XML tag
                break;
            case Xml.TEXT:
                ..... // handle text within a tag
                break;
            case Xml.WHITESPACE:
                ..... // handle whitespace
                break;
            case Xml.COMMENT:
                ..... // handle comment
                break;
            case Xml.PROCESSING_INSTRUCTION:
                ..... // handle XML PI
                break;
            case Xml.DOCTYPE:
                ..... // handle XML doctype
                break;
            case Xml.END_DOCUMENT:
                ..... // end of document;
                keepParsing = false;
                break;
        }
    }
}
catch( java.io.IOException e ){
}

下面是一个J2ME的应用程序简单演示了如何解析xml。如果有时间可以写写复杂的测试程序。你可以从如下地址下载源代码：XMLTest. 里面包括了kxml和nanoxml的源代码，如果想得到最新的源代码请参考他们的官方网站，在本站提供了kxml的在线API
package com.ericgiguere.techtips;

import java.io.*;
import java.util.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
import nanoxml.*;

import org.kxml.*;
import org.kxml.parser.*;

/**
 * Simple MIDlet that demonstrates how an XML document can be
 * parsed using kXML or NanoXML.
 */

public class XMLTest extends MIDlet {

    // Our XML document -- normally this would be something you
    // download.
   
    private static String xmlDocument =
        "<list><item>apple</item>" +
              "<item>orange</item>" +
              "<item>pear</item></list>";
             
    private Display display;
    private Command exitCommand = new Command( "Exit",
                                               Command.EXIT, 1 );
                                              
    public XMLTest(){
    }
   
    protected void destroyApp( boolean unconditional )
                       throws MIDletStateChangeException {
        exitMIDlet();
    }
   
    protected void pauseApp(){
    }
   
    protected void startApp() throws MIDletStateChangeException {
        if( display == null ){ // first time called...
            initMIDlet();
        }
    }
   
    private void initMIDlet(){
        display = Display.getDisplay( this );
       
        String [] items;
       
        //items = parseUsingNanoXML( xmlDocument );
        items = parseUsingkXML( xmlDocument );
       
        display.setCurrent( new ItemList( items ) );
    }
   
    public void exitMIDlet(){
        notifyDestroyed();

}
   
    private String[] parseUsingkXML( String xml ){
        try {
            ByteArrayInputStream bin = new ByteArrayInputStream(
                                     xml.getBytes() );
            InputStreamReader in = new InputStreamReader( bin );
            XmlParser parser = new XmlParser( in );
            Vector    items = new Vector();
           
            parsekXMLItems( parser, items );
           
            String[] tmp = new String[ items.size() ];
            items.copyInto( tmp );
            return tmp;
        }
        catch( IOException e ){
            return new String[]{ e.toString() };
        }
    }
   
    private void parsekXMLItems( XmlParser parser, Vector items )
                                     throws IOException {
        boolean inItem = false;
       
        while( true ){
            ParseEvent event = parser.read();
            switch( event.getType() ){
                case Xml.START_TAG:
                    if( event.getName().equals( "item" ) ){
                        inItem = true;
                    }
                    break;
                case Xml.END_TAG:
                 if( event.getName().equals( "item" ) ){
                        inItem = false;
                    }
                    break;
                case Xml.TEXT:
                    if( inItem ){
                        items.addElement( event.getText() );
                    }
                    break;
                case Xml.END_DOCUMENT:
                    return;
            }
        }
    }
   
    // Simple List UI component for displaying the list of
    // items parsed from the XML document.
   
    class ItemList extends List implements CommandListener {
   
        ItemList( String[] list ){
            super( "Items", IMPLICIT, list, null );
            addCommand( exitCommand );
            setCommandListener( this );
        }
       
        public void commandAction( Command c, Displayable d ){
            if( c == exitCommand ){
                exitMIDlet();
            }
        }
    }
}