【Android】SAX解析XML（20110926更新）

SAX是事件驅動型XML解析接口

優點：解析速度快，內存消耗小

适合Android等移动设备

示例：

在assets建立用於解析的XML文件source.xml

<?xml version="1.0" encoding="UTF-8"?><xml><android><version>2.1</version><name>Eclair</name></android><android><version>2.2</version><name>Froyo</name></android><android><version>2.3</version><name>Gingerbread</name></android></xml>

新建一個Activity，我們將在ListView中顯示解析結果

package lizhen.sax;import java.io.IOException;import java.io.InputStream;import java.util.LinkedList;import java.util.List;import java.util.Map;import javax.xml.parsers.ParserConfigurationException;import org.xml.sax.SAXException;import android.app.Activity;import android.content.Context;import android.os.Bundle;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.ListView;import android.widget.TextView;public class Main extends Activity {    public static final String TAG = "Main";private ListView contentListView;private List<Map<String, String>> data = new LinkedList<Map<String,String>>();  //結果數據    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                contentListView = (ListView) findViewById(R.id.main_ContentListView);        try {        InputStream xml = getAssets().open("source.xml"); //從assets中讀入數據源        MySAXParser parser = new MySAXParser(); parser.parse(xml); //對輸入流進行解析data = parser.getResult(); //獲得解析結果} catch (ParserConfigurationException e) {Log.e(TAG, e.getMessage());} catch (SAXException e) {Log.e(TAG, e.getMessage());} catch (IOException e) {Log.e(TAG, e.getMessage());}        contentListView.setAdapter(new ContentListAdapter(this, data));    }        private class ContentListAdapter extends BaseAdapter {        private Context context;    private List<Map<String, String>> data;        public ContentListAdapter(Context context, List<Map<String, String>> data) {    this.context = context;    this.data = data;    }@Overridepublic int getCount() {return data.size();}@Overridepublic Object getItem(int position) {return data.get(position);}@Overridepublic long getItemId(int position) {return position;}@Overridepublic View getView(int position, View convertView, ViewGroup parent) {View result = convertView;if(result == null) {result = LayoutInflater.from(context).inflate(R.layout.main_item, null);}TextView versionTextView = (TextView) result.findViewById(R.id.main_VersionTextView);TextView nameTextView = (TextView) result.findViewById(R.id.main_NameTextView);versionTextView.setText(data.get(position).get(MySAXParser.ELEMENT_VERSION));nameTextView.setText(data.get(position).get(MySAXParser.ELEMENT_NAME));return result;}        }     }

SAX解析類

通過繼承DefaultHandler，重寫父類方法，對解析XML的過程中觸發的事件進行响应

DefaultHandler常用的囘調方法有：

startDocument 文檔開始
startElement 元素開始
uri 命名空间URI
localName 不带命名空间标签的元素名
qName 带命名空间的元素名
attributes 元素属性
characters 元素內部字符數據
ch 字符数组
start 字符数组开始位置
length 使用字符数组的长度
endElement 元素结束
uri 命名空间URI
localName 不带命名空间标签的元素名
qName 带命名空间的元素名
endDocument 文檔結尾

package lizhen.sax;import java.io.IOException;import java.io.InputStream;import java.io.StringReader;import java.util.HashMap;import java.util.LinkedList;import java.util.List;import java.util.Map;import javax.xml.parsers.ParserConfigurationException;import javax.xml.parsers.SAXParser;import javax.xml.parsers.SAXParserFactory;import org.xml.sax.Attributes;import org.xml.sax.InputSource;import org.xml.sax.SAXException;import org.xml.sax.XMLReader;import org.xml.sax.helpers.DefaultHandler;import android.util.Log;public class MySAXParser {public static final String ELEMENT_ANDROID = "android";public static final String ELEMENT_VERSION = "version";public static final String ELEMENT_NAME = "name";private List<Map<String, String>> result = new LinkedList<Map<String,String>>();public void parse(InputStream xml) throws ParserConfigurationException, SAXException, IOException {SAXParserFactory saxParserFactory = SAXParserFactory.newInstance(); //調用靜態方法newInstance得到SAXParseFactory實例SAXParser saxParser = saxParserFactory.newSAXParser(); //調用newSAXParser創建SAXParser對象XMLReader xmlReader = saxParser.getXMLReader(); //獲得XMLReader對象xmlReader.setContentHandler(new MySAXHandler()); //設置處理XML的HandlerxmlReader.parse(new InputSource(xml)); //將InputStream裝飾為InputSource，進行解析}private class MySAXHandler extends DefaultHandler {private String currentElement;private Map<String, String> android;@Overridepublic void startElement(String uri, String localName, String qName,Attributes attributes) throws SAXException {super.startElement(uri, localName, qName, attributes);currentElement = localName;if(ELEMENT_ANDROID.equals(currentElement)) {android = new HashMap<String, String>();}}@Overridepublic void characters(char[] ch, int start, int length)throws SAXException {super.characters(ch, start, length);if(ELEMENT_VERSION.equals(currentElement)){android.put(ELEMENT_VERSION, new String(ch, start, length));} else if(ELEMENT_NAME.equals(currentElement)) {android.put(ELEMENT_NAME, new String(ch, start, length));}}@Overridepublic void endElement(String uri, String localName, String qName)throws SAXException {super.endElement(uri, localName, qName);if(ELEMENT_ANDROID.equals(localName)) {result.add(android);}}}public List<Map<String, String>> getResult() {return this.result;}}

運行結果：

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