LyricXMLParser.java

package com.lq.util;

import java.io.InputStream;
import java.util.ArrayList;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

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

import android.util.Log;

/**
 * @author lq 2013-6-1 lq2625304@gmail.com
 * */
public class LyricXMLParser {
	private static final String TAG = "LyricXMLParser";

	private final String ELEMENT_COUNT = "count";
	private final String ELEMENT_LRCID = "lrcid";

	public int parseLyricId(InputStream is) throws Exception {
		SAXParserFactory factory = SAXParserFactory.newInstance(); // 取得SAXParserFactory实例
		SAXParser parser = factory.newSAXParser(); // 从factory获取SAXParser实例
		MyHandler handler = new MyHandler(); // 实例化自定义Handler
		parser.parse(is, handler); // 根据自定义Handler规则解析输入流
		is.close();
		return handler.getFirstLyricId();
	}

	class MyHandler extends DefaultHandler {
		private int mSongCount = 0;
		private ArrayList<Integer> mLyricIds = new ArrayList<Integer>();
		private StringBuilder mStringBuilder = new StringBuilder();;

		public int getSongCount() {
			return mSongCount;
		}

		// 若解析出多个lyricID，只返回第一个
		public int getFirstLyricId() {
			if (mSongCount == 0) {
				return -1;
			} else {
				return mLyricIds.get(0);
			}
		}

		@Override
		public void startDocument() throws SAXException {
			super.startDocument();
			mLyricIds.clear();
		}

		@Override
		public void endDocument() throws SAXException {
			super.endDocument();
		}

		@Override
		public void startElement(String uri, String localName, String qName,
				Attributes attributes) throws SAXException {
			super.startElement(uri, localName, qName, attributes);
			mStringBuilder.setLength(0); // 将字符长度设置为0 以便重新开始读取元素内的字符节点
		}

		@Override
		public void endElement(String uri, String localName, String qName)
				throws SAXException {
			super.endElement(uri, localName, qName);
			if (localName.equals(ELEMENT_COUNT)) {
				mSongCount = Integer.valueOf(mStringBuilder.toString());
				Log.i(TAG, "解析出的匹配歌曲数目:" + mSongCount);
			}
			if (localName.equals(ELEMENT_LRCID)) {
				Log.i(TAG, "歌词下载id:" + mStringBuilder.toString());
				mLyricIds.add(Integer.valueOf(mStringBuilder.toString()));
			}
		}

		@Override
		public void characters(char[] ch, int start, int length)
				throws SAXException {
			super.characters(ch, start, length);
			mStringBuilder.append(ch, start, length); // 将读取的字符数组追加到builder中
		}
	}
}