下载网络文件到SD卡上

下面一个一个类的来进行介绍: 
1.DownLoadProgress.java主控件界面: 

package cn.com;

import android.app.Activity;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
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;

public class DownLoadProgress extends Activity {

 private Button download;// 下载按钮
 private MediaPlayer mMediaPlayer;
 Thread downThread;// 下载子线程
 private ProgressBar myProgressBar;//显示进度条的ProgressBar
 TextView resultView;
 //子线程发送消息给UI线程来更新ProgressBar的进度
 private Handler handler = new Handler() {
  public void handleMessage(Message msg) {
   if (!Thread.currentThread().isInterrupted()) {
    switch (msg.what) {
    case 1:
     int size = msg.getData().getInt("size");
     myProgressBar.setProgress(size);// 设置当前刻度
     int result = (int) (((float) myProgressBar.getProgress() / (float) myProgressBar
       .getMax()) * 100);
     resultView.setText(result + "%");
     if (myProgressBar.getMax() == myProgressBar.getProgress()) {
      Toast.makeText(DownLoadProgress.this, R.string.success,
        1).show();
     }
     break;
    case -1:
     String error = msg.getData().getString("error");
     Toast.makeText(DownLoadProgress.this, error, 1).show();
     break;
    }

   }
   super.handleMessage(msg);
  }
 };

 public Thread getThreadInstance() {
  return downThread;
 }

 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);

  //在SD卡上新建文件夹来进行文件存储
  DirectoryHelper fileHelper = new DirectoryHelper();
  fileHelper.getSdCardPath();

  myProgressBar = (ProgressBar) findViewById(R.id.progressBar);
  resultView = (TextView) findViewById(R.id.result);

  download = (Button) findViewById(R.id.download);
  download.setOnClickListener(new OnClickListener() {
   public void onClick(View v) {
    downLoadVideo();
   }
  });
 }

 //新起一个线程进行文件下载
 public void downLoadVideo() {
  mMediaPlayer = new MediaPlayer();
  // Sets the audio stream type for this MediaPlayer
  mMediaPlayer.setAudioStreamType(2);
  MediaPlayerListener listener = new MediaPlayerListener();
  listener.setAllListener(mMediaPlayer);

  ThreadForRunnable thread = new ThreadForRunnable(this, myProgressBar,
    handler);
  new Thread(thread).start();
 }
}

2.当启动一个新线程后,就调用ThreadForRunnable类,此类实现了Runnable接口的类,就调用此类的run方法: ThreadForRunnable.java文件内容: 

package cn.com;

import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.ProgressBar;

public class ThreadForRunnable implements Runnable {
 String TAG = "***********************";

 Context con;
 ProgressBar myProgressBar;
 Handler handler;

 public ThreadForRunnable(Context con, ProgressBar myProgressBar,
   Handler handler) {
  this.con = con;
  this.myProgressBar = myProgressBar;
  this.handler = handler;
 }

 @Override
 public void run() {

  // http://lh5.ggpht.com/_2N-HvtdpHZY/SYjwSZO8emE/AAAAAAAABGI/EHe7N52mywg/s144-c/20090129.jpg
  // http://forum.ea3w.com/coll_ea3w/attach/2008_10/12237832415.3gp
  //String url = "http://www.dubblogs.cc:8751/Android/Test/Media/3gp/test.3gp";
  //String url = "http://net.itcast.cn/QQWubiSetup.exe";
  String url = "http://wd.ggzx.net/myfile/xinge/wozaizheli.mp3";
  try {
   // 在线程运行中，调用自定义函数抓下文件
   VideoDownload vd = new VideoDownload(con, url, handler);
   vd.setDataSource1();
   //vd.setDataSource1();// 下特定视频文件
   //vd.setDataSource2();//下载exe文件
   //vd.setDataSource();// 下载apk文件
   //vd.videoGet();
   myProgressBar.setMax((int) vd.getFileSize());// 设置进度条的最大刻度
  } catch (Exception e) {
   Message msg = new Message();
   msg.what = -1;
   msg.getData().putString("error", "下载失败");
   handler.sendMessage(msg);
   Log.e(TAG, e.toString());
  }

 }

}

 3.VideoDownload.java这个类文件主要是对各种文件进行下载的一些方法,里面我只使用了setDataSource1()方法,其他的方法,大家可以自己进行测试: 

package cn.com;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

public class VideoDownload {
 String TAG = "***********************";
 Context con;
 private String downloadUrl;// 下载路径
 File dFile1;
 FileOutputStream outs1;
 private long fileSize = 0;// 原始文件大小
 Handler handler;

 /**
  * 获取文件大小
  *
  * @return
  */
 public long getFileSize() {
  return fileSize;
 }

 public VideoDownload(Context con, String url, Handler handler) {
  this.con = con;
  this.downloadUrl = url;
  this.handler = handler;
 }

 public void videoGet() {//下载一个视频
  try {
   DefaultHttpClient httpclient = new DefaultHttpClient();
   HttpResponse response;
   HttpPost httpost = new HttpPost(Constants.videoURL);
   List<NameValuePair> nvps = new ArrayList<NameValuePair>();
   nvps.add(new BasicNameValuePair("type", "video"));
   nvps.add(new BasicNameValuePair("id", String.valueOf(29)));
   nvps.add(new BasicNameValuePair("fileId", String.valueOf(1)));
   httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));
   // This is always a final response
   response = httpclient.execute(httpost);
   HttpEntity entity = response.getEntity();
   fileSize = entity.getContentLength();
   System.out.println("fileSize----------->" + fileSize);
   InputStream is = entity.getContent();
   if (is == null) {
    // 680kb
    throw new RuntimeException("stream is null");
   }
   dFile1 = new File(Constants.filePath, 29 + ".mp4");
   FileOutputStream fos = new FileOutputStream(dFile1);
   int numread = 0;
   int readLen = 0;
   byte buf[] = new byte[128];
   do {
    numread = is.read(buf);
    readLen = readLen + numread;
    System.out.println("readLen----------->" + readLen);
    if (fileSize != -1 ) {
     updateProgressBar(readLen);
    }

    if (numread < 0) {
     break;
    }
    fos.write(buf, 0, numread);
   } while (true);
   is.close();
  } catch (Exception e) {
   e.printStackTrace();
  }
 }

 public void apkGet() {
  try {
   DefaultHttpClient httpclient = new DefaultHttpClient();
   HttpResponse response;
   HttpPost httpost = new HttpPost(Constants.imageURL);

   List<NameValuePair> nvps = new ArrayList<NameValuePair>();

   nvps.add(new BasicNameValuePair("type", "demo"));
   nvps.add(new BasicNameValuePair("id", String.valueOf(29)));
   nvps.add(new BasicNameValuePair("fileId", "1"));

   httpost.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));

   // This is always a final response
   response = httpclient.execute(httpost);

   HttpEntity entity = response.getEntity();

   fileSize = entity.getContentLength();
   System.out.println("fileSize----------->" + fileSize);

   InputStream is = entity.getContent();
   System.out.println("***************************" + is);

   dFile1 = new File(Constants.filePath, 29 + ".apk");

   outs1 = new FileOutputStream(dFile1);
   byte buf[] = new byte[1024];
   int numread = 0;

   int readLen = 0;

   do {
    // Start reading data from the URL stream
    numread = is.read(buf);
    readLen = readLen + numread;
    updateProgressBar(readLen);

    if (numread < 0) {
     System.out.println("the end !!!!");
     break;
    }
    outs1.write(buf, 0, numread);

   } while (true);
   // openFile(dFile1);
   System.out.println("_____apk download success!!!_____");
  } catch (Exception e) {
   e.printStackTrace();
  }

 }

 //更新进度条(当可以通过getContentLength来获取文件长度的情况下)
 public void updateProgressBar(int readLen) {
  Message msg = new Message();
  msg.what = 1;
  msg.getData().putInt("size", readLen);
  //通过主线程的handler通知主线程更新UI进度条的进度
  handler.sendMessage(msg);
 }

 /* 自定义setDataSource，由线程启动 */
 public void setDataSource1() throws Exception {

  URL myURL = new URL(downloadUrl);
  URLConnection conn = myURL.openConnection();
  conn.connect();
  InputStream is = conn.getInputStream();

  //当可以返回下载文件大小的情况下
  //方便后续显示进度条的总内容长度
  fileSize = conn.getContentLength();

  System.out.println("fileSize--------------->" + fileSize);

  //将下载文件保存到指定文件夹
  File myFileTemp = new File(Constants.filePath, "video."
    + getFileExtension(downloadUrl));

  // the file to which this stream writes
  FileOutputStream fos = new FileOutputStream(myFileTemp);
  byte buf[] = new byte[128];
  int numread = 0;
  int readLen = 0;
  do {
   numread = is.read(buf);
   if (numread <= 0) {
    break;
   }
   fos.write(buf, 0, numread);
   readLen = readLen + numread;
   System.out.println("readLen----------->" + readLen);
   if(fileSize != -1)
    //不断的更新进度条
   updateProgressBar(readLen);

  } while (true);

  try {
   is.close();
   System.out.println("Download is over!!!!!!");
  } catch (Exception ex) {
   Log.e(TAG, "error: " + ex.getMessage(), ex);
  }
 }

 //下载特定类型文件
 public void setDataSource2() throws Exception {

  URL myURL = new URL(downloadUrl);

  HttpURLConnection conn = (HttpURLConnection) myURL.openConnection();
  conn.setConnectTimeout(6 * 1000);
  conn.setRequestMethod("GET");
  conn.setRequestProperty(
    "Accept",
    "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");
  conn.setRequestProperty("Accept-Language", "zh-CN");
  conn.setRequestProperty("Referer", downloadUrl);
  conn.setRequestProperty("Charset", "UTF-8");
  conn.setRequestProperty(
    "User-Agent",
    "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
  conn.setRequestProperty("Connection", "Keep-Alive");
  conn.connect();

  InputStream is = conn.getInputStream();

  fileSize = conn.getContentLength();

  System.out.println("fileSize--------------->" + fileSize);

  File myFileTemp = new File(Constants.filePath, "video."
    + getFileExtension(downloadUrl));

  // the file to which this stream writes
  FileOutputStream fos = new FileOutputStream(myFileTemp);
  byte buf[] = new byte[128];
  int numread = 0;
  int readLen = 0;
  do {
   numread = is.read(buf);
   if (numread <= 0) {
    break;
   }
   fos.write(buf, 0, numread);
   readLen = readLen + numread;
   updateProgressBar(readLen);

  } while (true);

  try {
   is.close();
   System.out.println("Download is over!!!!!!");
  } catch (Exception ex) {
   Log.e(TAG, "error: " + ex.getMessage(), ex);
  }
 }

 // 取得加载文件的后缀名
 private String getFileExtension(String strFileName) {
  File myFile = new File(strFileName);
  String strFileExtension = myFile.getName();
  strFileExtension = (strFileExtension.substring(strFileExtension
    .lastIndexOf(".") + 1)).toLowerCase();

  if (strFileExtension == "") {
   /* 若无法顺利取得扩展名，默认为.dat */
   strFileExtension = "dat";
  }
  return strFileExtension;
 }
}

4.DirectoryHelper.java文件,这个文件是在判断SD卡是否存在需要的文件夹的判断,如果没有就新建目标文件夹 

package cn.com;

import java.io.File;
import android.os.Environment;

public class DirectoryHelper
{
 //构建应用在SD卡上的相关文件夹
 public void getSdCardPath()
 {
  File sdcardDir = Environment.getExternalStorageDirectory();
  String path = sdcardDir.getParent() + sdcardDir.getName();
  Constants.filePath = path + java.io.File.separator + "VideoDownLoad";
  System.out.println("__________" + Constants.filePath);
  createFile();
 }

 public void createFile()
 {
  try
  {
   // 1.判断是否存在sdcard
   if (Environment.MEDIA_MOUNTED.equals(Environment
     .getExternalStorageState()))
   {
    // 目录
    System.out.println("_______create Directory________");
    File path = new File(Constants.filePath);
    if (!path.exists())
    {
     // 2.创建目录，可以在应用启动的时候创建
     path.mkdirs();
    }
    // 文件
    // File f = new File(fileDirectory + "/notes.txt");
    // if (!f.exists()) {
    // // 3.创建文件
    // f.createNewFile();
    // }

   }
  } catch (Exception e)
  {
   e.printStackTrace();
  }
 }
}

 5.Constants.java这是个常量类: 

package cn.com;

public class Constants {
       //这里的地址大家可以自己修改下
 public static String filePath = "";
 public final static String HOST = "********";
 public final static int PORT = **;
 public final static String HOST_IP = "http://" + HOST + ":" + PORT;
 public static String imageURL = HOST_IP + "****************";
 public final static String videoURL = HOST_IP
   + "********";
}

6.MediaPlayerListener.java这个文件主要是在文件下载完成后的一些额外播放操作: 

package cn.com;

import android.media.MediaPlayer;
import android.util.Log;

public class MediaPlayerListener {
 String TAG = "_____TAG_____";

 public MediaPlayerListener() {

 }

 public void setAllListener(MediaPlayer mMediaPlayer) {
  mMediaPlayer.setOnErrorListener(new MediaPlayer.OnErrorListener() {
   @Override
   public boolean onError(MediaPlayer mp, int what, int extra) {
    // TODO Auto-generated method stub
    Log.i(TAG, "Error on Listener, what: " + what + "extra: "
      + extra);
    return false;
   }
  });

  mMediaPlayer
    .setOnBufferingUpdateListener(new MediaPlayer.OnBufferingUpdateListener() {
     @Override
     public void onBufferingUpdate(MediaPlayer mp, int percent) {
      // TODO Auto-generated method stub
      Log.i(TAG, "Update buffer: "
        + Integer.toString(percent) + "%");
     }
    });

  mMediaPlayer
    .setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
     @Override
     public void onCompletion(MediaPlayer mp) {
      // TODO Auto-generated method stub
      Log.i(TAG, "mMediaPlayer Listener Completed");
     }
    });

  mMediaPlayer
    .setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
     @Override
     public void onPrepared(MediaPlayer mp) {
      // TODO Auto-generated method stub
      Log.i(TAG, "Prepared Listener");
     }
    });
 }
}

 最后一个类我基本没有用上,也懒得删除掉了,因为后续完善代码的时候肯定也会用上; 

7.main.xml文件很简单: 

<?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">
 <ProgressBar android:layout_width="fill_parent"
  android:layout_height="18dip" style="?android:attr/progressBarStyleHorizontal"
  android:id="@+id/progressBar" />
 <TextView android:layout_width="fill_parent"
  android:layout_height="wrap_content" android:gravity="center"
  android:id="@+id/result" />
 <Button android:text="download" android:id="@+id/download"
  android:layout_width="wrap_content" android:layout_height="wrap_content"></Button>
</LinearLayout>

 8.最后是配置文件: 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="cn.com" android:versionCode="1" android:versionName="1.0">
 <application android:icon="@drawable/icon" android:label="@string/app_name">
  <activity android:name=".DownLoadProgress" android:label="@string/app_name">
   <intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
   </intent-filter>
  </activity>

 </application>
 <!-- 在SDCard中创建与删除文件权限 -->
 <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
 <!-- 往SDCard写入数据权限 -->
 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <!-- 访问internet权限 -->
 <uses-permission android:name="android.permission.INTERNET" />
</manifest>