Android 解析XML 之SAX

<span style="font-size: 18px;">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。</span>

1：创建SAXParserFactory对象

2: 根据SAXParserFactory.newSAXParser()方法返回一个SAXParser解析器
3：根据SAXParser解析器获取事件源对象XMLReader
4：实例化一个DefaultHandler对象

5：连接事件源对象XMLReader到事件处理类DefaultHandler中

6：调用XMLReader的parse方法从输入源中获取到的xml数据

7：通过DefaultHandler返回我们需要的数据集合。

首先在 res目录下新建一个raw文件夹，然后再里面么新建一个student.xml

student.xml

<?xml version="1.0" encoding="utf-8"?>  
<stundets>
  <student id="2009081315">
    <name>饶伟</name>
    <speciality>计算机科学与技术</speciality>
    <qq>812200157</qq>
  </student>

    <student id="2009081316">
    <name>小伟</name>
    <speciality>网络工程</speciality>
    <qq>812200156</qq>
  </student>
    <student id="2009081318">
    <name></name>
    <speciality>软件工程</speciality>
    <qq>812200158</qq>
  </student>

</stundets>

Student.java

public class Student {

	long Id;
	String Name;
	String Speciality;
	long QQ;
	
	public Student(long id, String name, String speciality, long qQ) {
		super();
		Id = id;
		Name = name;
		Speciality = speciality;
		QQ = qQ;
	}

	public Student() {
		super();
	}

	
	public long getId() {
		return Id;
	}

	public String getName() {
		return Name;
	}

	public long getQQ() {
		return QQ;
	}

	public String getSpeciality() {
		return Speciality;
	}

	public void setId(long id) {
		Id = id;
	}

	public void setName(String name) {
		Name = name;
	}

	public void setQQ(long qQ) {
		QQ = qQ;
	}

	public void setSpeciality(String speciality) {
		Speciality = speciality;
	}

}

StudentHandler.java

package rw.Xml_SAX;

import java.util.List;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import android.util.Log;

public class StudentHandler extends DefaultHandler {


	private String preTAG;  
	private List<Student> ListStudent;
	private Student stu;
	
	public StudentHandler() {
		super();
	}

	public StudentHandler(List<Student> listStudent) {
		super();
		ListStudent = listStudent;
	}


	public void startDocument() throws SAXException {
		// TODO Auto-generated method stub
	Log.i("------>", "文档开始");
		super.startDocument();
	}

	public void startElement(String uri, String localName, String qName,
			Attributes attributes) throws SAXException {


		Log.i("localName-------->", localName);
	    preTAG=localName;
		if ("student".equals(localName)) {
			stu=new Student();
			stu.setId(Long.parseLong(attributes.getValue(0)));
			
		for (int i = 0; i < attributes.getLength(); i++) {
			//Log.i("attributes-------->", attributes.getValue(i));
			Log.i("attributes-------->",String.valueOf(stu.getId()));
		}
	}
		super.startElement(uri, localName, qName, attributes);
	}

	public void endDocument() throws SAXException {
	
		Log.i("------>", "文档结束");
		super.endDocument();
	}

	public void endElement(String uri, String localName, String qName)
			throws SAXException {
	    preTAG="";
        if ("student".equals(localName)) {
    	ListStudent.add(stu);
      	Log.i("-------->", "一个元素解析完成");
        }
		super.endElement(uri, localName, qName);
	}
	
	
public void characters(char[] ch, int start, int length)
		throws SAXException {
	
		String dateString;
	   if ("name".equals(preTAG)) {
			dateString=new String(ch,start,length);
			stu.setName(dateString);
			Log.i("name=", stu.getName());
		}else if ("speciality".equals(preTAG)) {
			dateString=new String(ch,start,length);
			stu.setSpeciality(dateString);
			Log.i("speciality=", stu.getSpeciality());
		}else if ("qq".equals(preTAG)) {
			dateString=new String(ch,start,length);
			stu.setQQ(Long.parseLong((dateString)));
			Log.i("QQ=", String.valueOf(stu.getQQ()));
		}

	    super.characters(ch, start, length);
}


}

XML_Sax1Activity.java（唯一的一个activity）

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;


import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Adapter;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;

public class XMl_Sax1Activity extends Activity {
      private Button button;
      private TextView textView;
      private ListView listView;
      private List<String> list=new ArrayList<String>();
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        button=(Button)findViewById(R.id.button1);
        textView=(TextView)findViewById(R.id.textView1);
        listView=(ListView) findViewById(R.id.listView1);
        //InputSource xMLResourceString=new InputSource(XMl_Sax1Activity.this.getResources().openRawResource(R.raw.student));
        button.setOnClickListener(new ButtonListener());
    }

    class ButtonListener implements OnClickListener{

		@Override
		public void onClick(View v) {
			   
	           List<Student> students=parserXMl();
	           for (Iterator iterator = students.iterator(); iterator.hasNext();) {
			   Student student = (Student) iterator.next();
				list.add(String.valueOf(student.getId())+" "+student.getName()+" "+student.getSpeciality()+" "+String.valueOf((student.getQQ())));
			}
	       
	           ArrayAdapter<String> adapter=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, list);
               listView.setAdapter(adapter);
		}
    	
    }
    
  private List<Student> parserXMl()
  {
		SAXParserFactory factory=SAXParserFactory.newInstance();
		List<Student>students=null;
		Student student=null;
		try {
			XMLReader reader=factory.newSAXParser().getXMLReader();
			students=new ArrayList<Student>();
			reader.setContentHandler(new StudentHandler(students));
			reader.parse(new InputSource(XMl_Sax1Activity.this.getResources().openRawResource(R.raw.student)));
					} catch (Exception e) {
			// TODO: handle exception
		}
		return students;
  }
}

布局文件main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

<Button android:text="SAX解析" android:id="@+id/button1" android:layout_height="wrap_content" android:layout_width="match_parent"></Button>
<TextView android:text="" android:id="@+id/textView1" android:layout_width="wrap_content" android:layout_height="wrap_content"></TextView>
<ListView android:layout_height="wrap_content" android:id="@+id/listView1" android:layout_width="match_parent"></ListView>
</LinearLayout>

运行效果