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Android学习笔记之XML解析(SAX)

SAX是一种占用内存少且解析速度快的解析器,它采用的是事件启动,它不需要解析完整个文档,而是按照内容顺序 看文档某个部分是否符合xml语法,如果符合就触发相应的事件,所谓的事件就是些回调方法(callback),这些方法 定义在ContentHandler中,下面是其主要方法:
 
startDocument:当遇到文档的时候就触发这个事件 调用这个方法 可以在其中做些预处理工作
 
startElement: (String namespaceURI,String localName,String qName,Attributes atts)当遇开始标签的时候就会触发这个方法。
 
endElement(String uri,String localName,String name):当遇到结束标签时触发这个事件,调用此法可以做些善后工作。
 
charachers(char [] ch,int start,int length):当遇到xml内容时触发这个方法,用new String(ch,start,length)可以接受内容。
MyContentHandler.java
 
package mars.xml; 
 
import org.xml.sax.Attributes; 
import org.xml.sax.SAXException; 
import org.xml.sax.helpers.DefaultHandler; 
 
public class MyContentHandler extends DefaultHandler { 
    String hisname, address, money, sex, status; 
    String tagName; 
 
    public void startDocument() throws SAXException { 
        System.out.println("````````begin````````"); 
    } 
 
    public void endDocument() throws SAXException { 
        System.out.println("````````end````````"); 
    } 
 
    public void startElement(String namespaceURI, String localName, 
            String qName, Attributes attr) throws SAXException { 
        tagName = localName; 
        if (localName.equals("worker")) { 
            //获取标签的全部属性 
            for (int i = 0; i < attr.getLength(); i++) { 
                System.out.println(attr.getLocalName(i) + "=" + attr.getValue(i)); 
            } 
        } 
    } 
 
    public void endElement(String namespaceURI, String localName, String qName) 
            throws SAXException { 
        //在workr标签解析完之后,会打印出所有得到的数据 
        tagName = ""; 
        if (localName.equals("worker")) { 
            this.printout(); 
        } 
    } 
    public void characters(char[] ch, int start, int length) 
            throws SAXException { 
        if (tagName.equals("name")) 
            hisname = new String(ch, start, length); 
        else if (tagName.equals("sex")) 
            sex = new String(ch, start, length); 
        else if (tagName.equals("status")) 
            status = new String(ch, start, length); 
        else if (tagName.equals("address")) 
            address = new String(ch, start, length); 
        else if (tagName.equals("money")) 
            money = new String(ch, start, length); 
    } 
 
    private void printout() { 
        System.out.print("name: "); 
        System.out.println(hisname); 
        System.out.print("sex: "); 
        System.out.println(sex); 
        System.out.print("status: "); 
        System.out.println(status); 
        System.out.print("address: "); 
        System.out.println(address); 
        System.out.print("money: "); 
        System.out.println(money); 
        System.out.println(); 
    } 
 

XMLActitity.java
 
package mars.xml; 
 
import java.io.StringReader; 
 
import javax.xml.parsers.SAXParserFactory; 
 
import mars.utils.HttpDownloader; 
 
import org.xml.sax.InputSource; 
import org.xml.sax.XMLReader; 
 
import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
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public class XMLActitity extends Activity { 
    /** Called when the activity is first created. */ 
    private Button parseButton ; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.main); 
        parseButton = (Button)findViewById(R.id.parseButton);  
        parseButton.setOnClickListener(new ParseButtonListener()); 
    } 
     
    class ParseButtonListener implements OnClickListener{ 
 
        public void onClick(View v) { 
            HttpDownloader hd = new HttpDownloader(); 
            String resultStr = hd.download("http://192.168.1.107:8081/voa1500/test.xml"); 
            System.out.println(resultStr); 
            try{ 
                //创建一个SAXParserFactory 
             
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