import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button; 
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

/**
 * 檔案下載
 * @author 胡漢三
 *
 */
public class MainActivity extends Activity {

	private static final String Path="檔案的HTTP地址/ttt.mp3";
	private static String fileName = "ttt.mp3";
	private static String filePath= "/download/";
	private ProgressBar progressBar; 
	private TextView textView;
	private Button button;
	private int FileLength;  
	private int DownedFileLength=0;
	private InputStream inputStream;
	private URLConnection connection;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		progressBar=(ProgressBar) findViewById(R.id.download_main_progressBarlist);
		textView=(TextView) findViewById(R.id.download_main_Text);
		button=(Button) findViewById(R.id.download_main_Button);
		button.setOnClickListener(new ButtonListener());

	}
	class ButtonListener implements OnClickListener{
		@Override
		public void onClick(View v) {
			DownedFileLength=0;
			Thread thread=new Thread(){
				public void run(){
					try {
						DownFile(Path);
					} catch (Exception e) { }
				} 
			};
			thread.start();
		}   
	}

	private Handler handler=new Handler()
	{
		public void handleMessage(Message msg)
		{
			if (!Thread.currentThread().isInterrupted()) {
				switch (msg.what) {
				case 0:
					progressBar.setMax(FileLength);
					Log.i("檔案長度----------->", progressBar.getMax()+"");  
					break;
				case 1:
					progressBar.setProgress(DownedFileLength);
					int x=DownedFileLength*100/FileLength;
					textView.setText(x+"%");
					break;
				case 2:
					Toast.makeText(getApplicationContext(), "下載完成", Toast.LENGTH_LONG).show();
					break;

				default:
					break;
				}
			}   
		}

	};

	private void DownFile(String urlString)
	{

		/*
		 * 連線到伺服器
		 */

		try {
			URL url=new URL(urlString);
			connection=url.openConnection();
			if (connection.getReadTimeout()==5) {
				Log.i("---------->", "當前網路有問題");
				// return;
			}
			inputStream=connection.getInputStream();

		} catch (MalformedURLException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}

		/*
		 * 檔案的儲存路徑和和檔名其中Nobody.mp3是在手機SD卡上要儲存的路徑，如果不存在則新建
		 */
		String savePAth=Environment.getExternalStorageDirectory()+filePath;
		File file1=new File(savePAth);
		if (!file1.exists()) {
			file1.mkdir(); 
		}
		String savePathString=Environment.getExternalStorageDirectory()+filePath+fileName;
		File file =new File(savePathString);
		if (!file.exists()) { 
			try {
				file.createNewFile();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}   
		}
		/*
		 * 向SD卡中寫入檔案,用Handle傳遞執行緒
		 */
		Message message=new Message();
		try {
			RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rwd");
			randomAccessFile.setLength(FileLength);
			byte[]buf = new byte[1024*4];
			FileLength=connection.getContentLength();
			message.what=0;
			handler.sendMessage(message);
			int length = 0;
			while ((length=inputStream.read(buf))!=-1) {
				randomAccessFile.write(buf,0,length);
				DownedFileLength+=length;
				Log.i("-------->", DownedFileLength+"");
				Message message1=new Message();
				message1.what=1;  
				handler.sendMessage(message1);
			}
			inputStream.close(); 
			randomAccessFile.close();
			Message message2=new Message();
			message2.what=2;
			handler.sendMessage(message2);
			
		} catch (FileNotFoundException e) {   
			// TODO Auto-generated catch block 
			e.printStackTrace(); 
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}