使用 XmlPull 解析 XML 的简单例子，xmlpullxml,XmlPull和Sax类

使用 XmlPull 解析 XML 的简单例子，xmlpullxml,XmlPull和Sax类

XmlPull和Sax类似，是基于流（stream）操作文件，然后根据节点事件回调开发者编写的处理程序。因为是基于流的处理，因此Xmlpull和Sax都比较节约内存资源，不会象Dom那样要把所有节点以对橡树的形式展现在内存中。

但Xmlpull比Sax更简明，而且不需要扫描完整个流。而MXP1是实现XmlPull的一个java类库

MyXmlPullApp.java

import java.io.FileReader;import java.io.IOException;import java.io.StringReader;import org.xmlpull.v1.XmlPullParser;import org.xmlpull.v1.XmlPullParserException;import org.xmlpull.v1.XmlPullParserFactory;/** * An example of an application that uses XMLPULL V1 API. * * @author <a href="http://www.extreme.indiana.edu/~aslom/">Aleksander Slominski</a> */public class MyXmlPullApp{    public final static String SAMPLE_XML =        "<?xml version=\"1.0\"?>\n"+        "\n"+        "<poem xmlns=\"http://www.megginson.com/ns/exp/poetry\">\n"+        "<title>Roses are Red</title>\n"+        "<l>Roses are red,</l>\n"+        "<l>Violets are blue;</l>\n"+        "<l>Sugar is sweet,</l>\n"+        "<l>And I love you.</l>\n"+        "</poem>";    public static void main (String args[])        throws XmlPullParserException, IOException    {        XmlPullParserFactory factory = XmlPullParserFactory.newInstance();        factory.setNamespaceAware(true);        XmlPullParser xpp = factory.newPullParser();        System.out.println("parser implementation class is "+xpp.getClass());        MyXmlPullApp app = new MyXmlPullApp();        if(args.length == 0) {            System.out.println("Parsing simple sample XML");//:\n"+ SAMPLE_XML);            xpp.setInput( new StringReader( SAMPLE_XML ) );            app.processDocument(xpp);        } else {            for (int i = 0; i < args.length; i++) {                System.out.println("Parsing file: "+args[i]);                xpp.setInput ( new FileReader ( args [i] ) );                app.processDocument(xpp);            }        }    }    public void processDocument(XmlPullParser xpp)        throws XmlPullParserException, IOException    {        int eventType = xpp.getEventType();        do {            if(eventType == xpp.START_DOCUMENT) {                System.out.println("Start document");            } else if(eventType == xpp.END_DOCUMENT) {                System.out.println("End document");            } else if(eventType == xpp.START_TAG) {                processStartElement(xpp);            } else if(eventType == xpp.END_TAG) {                processEndElement(xpp);            } else if(eventType == xpp.TEXT) {                processText(xpp);            }            eventType = xpp.next();        } while (eventType != xpp.END_DOCUMENT);    }    public void processStartElement (XmlPullParser xpp)    {        String name = xpp.getName();        String uri = xpp.getNamespace();        if ("".equals (uri)) {            System.out.println("Start element: " + name);        } else {            System.out.println("Start element: {" + uri + "}" + name);        }    }    public void processEndElement (XmlPullParser xpp)    {        String name = xpp.getName();        String uri = xpp.getNamespace();        if ("".equals (uri))            System.out.println("End element: " + name);        else            System.out.println("End element:   {" + uri + "}" + name);    }    int holderForStartAndLength[] = new int[2];    public void processText (XmlPullParser xpp) throws XmlPullParserException    {        char ch[] = xpp.getTextCharacters(holderForStartAndLength);        int start = holderForStartAndLength[0];        int length = holderForStartAndLength[1];        System.out.print("Characters:    \"");        for (int i = start; i < start + length; i++) {            switch (ch[i]) {                case '\\':                    System.out.print("\\\\");                    break;                case '"':                    System.out.print("\\\"");                    break;                case '\n':                    System.out.print("\\n");                    break;                case '\r':                    System.out.print("\\r");                    break;                case '\t':                    System.out.print("\\t");                    break;                default:                    System.out.print(ch[i]);                    break;            }        }        System.out.print("\"\n");    }}