MainActivity.java

package com.icss;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.ListActivity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;
import android.widget.ProgressBar;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

import com.icss.entity.LoadInfo;
import com.icss.service.Downloader;

public class MainActivity extends ListActivity {
	// 固定下载的资源路径，这里可以设置网络上的地址
	private static final String URL = "http://10.20.30.175/zentao/test_dir/";
	// 固定存放下载的音乐的路径：SD卡目录下
	private static final String SD_PATH = "/mnt/sdcard/";
	// 存放各个下载器
	private Map<String, Downloader> downloaders = new HashMap<String, Downloader>();
	// 存放与下载器对应的进度条
	private Map<String, ProgressBar> progressBars = new HashMap<String, ProgressBar>();
	/**
	 * 31 * 利用消息处理机制适时更新进度条 32
	 */
	private Handler mHandler = new Handler() {
		public void handleMessage(Message msg) {
			if (msg.what == 1) {
				String url = (String) msg.obj;
				int length = msg.arg1;
				ProgressBar bar = progressBars.get(url);
				if (bar != null) {
					// 设置进度条按读取的length长度更新
					bar.incrementProgressBy(length);
					if (bar.getProgress() == bar.getMax()) {
						Toast.makeText(MainActivity.this, "下载完成！", 0).show();
						// 下载完成后清除进度条并将map中的数据清空
						LinearLayout layout = (LinearLayout) bar.getParent();
						layout.removeView(bar);
						progressBars.remove(url);
						downloaders.get(url).delete(url);
						downloaders.get(url).reset();
						downloaders.remove(url);

					}
				}
			}
		}
	};

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		showListView();
	}

	// 显示listView，这里可以随便添加音乐
	private void showListView() {
		List<Map<String, String>> data = new ArrayList<Map<String, String>>();
		Map<String, String> map = new HashMap<String, String>();
		map.put("name", "test1.mp3");
		data.add(map);
		map = new HashMap<String, String>();
		map.put("name", "test2.mp3");
		data.add(map);
		map = new HashMap<String, String>();
		map.put("name", "test3.mp3");
		data.add(map);
		map = new HashMap<String, String>();
		map.put("name", "test4.mp3");
		data.add(map);
		SimpleAdapter adapter = new SimpleAdapter(this, data,
				R.layout.list_item, new String[] { "name" },
				new int[] { R.id.tv_resouce_name });
		setListAdapter(adapter);
	}

	/**
	 * 83 * 响应开始下载按钮的点击事件 84
	 */
	public void startDownload(View v) {
		// 得到textView的内容
		LinearLayout layout = (LinearLayout) v.getParent();
		String musicName = ((TextView) layout
				.findViewById(R.id.tv_resouce_name)).getText().toString();
		String urlstr = URL + musicName;
		String localfile = SD_PATH + musicName;
		// 设置下载线程数为4，这里是我为了方便随便固定的
		int threadcount = 4;
		// 初始化一个downloader下载器
		Downloader downloader = downloaders.get(urlstr);
		if (downloader == null) {
			downloader = new Downloader(urlstr, localfile, threadcount, this,
					mHandler);
			downloaders.put(urlstr, downloader);
		}
		if (downloader.isdownloading())
			return;
		// 得到下载信息类的个数组成集合
		LoadInfo loadInfo = downloader.getDownloaderInfors();
		// 显示进度条
		showProgress(loadInfo, urlstr, v);
		// 调用方法开始下载
		downloader.download();
	}

	/**
	 * 显示进度条
	 */
	private void showProgress(LoadInfo loadInfo, String url, View v) {
		ProgressBar bar = progressBars.get(url);
		if (bar == null) {
			bar = new ProgressBar(this, null,
					android.R.attr.progressBarStyleHorizontal);
			bar.setMax(loadInfo.getFileSize());
			bar.setProgress(loadInfo.getComplete());
			System.out.println(loadInfo.getFileSize() + "--"
					+ loadInfo.getComplete());
			progressBars.put(url, bar);
			LinearLayout.LayoutParams params = new LayoutParams(
					LayoutParams.FILL_PARENT, 5);
			((LinearLayout) ((LinearLayout) v.getParent()).getParent())
					.addView(bar, params);
		}
	}

	/**
	 * 响应暂停下载按钮的点击事件
	 */
	public void pauseDownload(View v) {
		LinearLayout layout = (LinearLayout) v.getParent();
		String musicName = ((TextView) layout
				.findViewById(R.id.tv_resouce_name)).getText().toString();
		String urlstr = URL + musicName;
		downloaders.get(urlstr).pause();
	}
}