使用FTP服務器的Intent下載文本文件。

Question

我正在使用ftp連接從服務器下載文本文件。 但偏偏我得到異常：

android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.PICK dat=64.78.178.19 typ=vnd.android.cursor.dir/lysesoft.andftp.uri (has extras) } 

我在manifest.xml中還定義了活動。下面

是我清單文件

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.saltriver.hourdoc" 
android:versionCode="1" 
android:versionName="1.0" > 

<uses-sdk android:minSdkVersion="8" /> 
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> 
<uses-permission android:name="android.permission.INTERNET"/> 


<application android:icon="@drawable/ic_launcher" android:label="@string/app_name"> 
    <activity android:name=".HourdocActivity" 
       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> 

代碼下載文本文件。

public void onCreate(Bundle savedInstanceState) 
{ 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    Button downloadFilesButton = (Button) findViewById(R.id.button_download_files_id); 
    downloadFilesButton.setOnClickListener(new View.OnClickListener() 
    { 
    public void onClick(View v) 
    { 
    Intent intent = new Intent(); 
    intent.setAction(Intent.ACTION_PICK); 
    // FTP URL (Starts with ftp://, sftp://, ftps:// or scp:// followed by hostname and port). 
    Uri ftpUri = Uri.parse(ConstantCodes.ftphost); 
    intent.setDataAndType(ftpUri, ConstantCodes.ftpuri); 
    // Download 
    intent.putExtra("command_type", "download"); 
    // FTP credentials (optional) 
    intent.putExtra("ftp_username", ConstantCodes.userid); 
    intent.putExtra("ftp_password", ConstantCodes.pwd); 
    //intent.putExtra("ftp_keyfile", "/sdcard/dsakey.txt"); 
    //intent.putExtra("ftp_keypass", "optionalkeypassword"); 
    // FTP settings (optional) 
    intent.putExtra("ftp_pasv", "true"); 
    //intent.putExtra("ftp_resume", "true"); 
    //intent.putExtra("ftp_encoding", "UTF-8"); 
    //intent.putExtra("ftps_mode", "implicit"); 
    // Activity title 
    intent.putExtra("progress_title", "Downloading files ..."); 
    // Remote files to download. 
    intent.putExtra("remote_file1", ConstantCodes.ftp_remotefile1); 
    //intent.putExtra("remote_file2", "/remotefolder/subfolder/file2.zip"); 
    // Target local folder where files will be downloaded. 
    intent.putExtra("local_folder", ConstantCodes.localfolder_path); 
    intent.putExtra("close_ui", "true"); 
    startActivityForResult(intent,ConstantCodes.DOWNLOAD_FILES_REQUEST); 
    } 
    }); 
} 

protected void onActivityResult(int requestCode, int resultCode, Intent intent) 
{ 
Log.i(TAG, "Result: "+resultCode+ " from request: "+requestCode); 
if (intent != null) 
{ 
    String transferredBytesStr = intent.getStringExtra("TRANSFERSIZE"); 
    String transferTimeStr = intent.getStringExtra("TRANSFERTIME"); 
    Log.i(TAG, "Transfer status: " + intent.getStringExtra("TRANSFERSTATUS")); 
    Log.i(TAG, "Transfer amount: " + intent.getStringExtra("TRANSFERAMOUNT") + " file(s)"); 
    Log.i(TAG, "Transfer size: " + transferredBytesStr + " bytes"); 
    Log.i(TAG, "Transfer time: " + transferTimeStr + " milliseconds"); 
    // Compute transfer rate. 
    if ((transferredBytesStr != null) && (transferTimeStr != null)) 
    { 
    try 
    { 
     long transferredBytes = Long.parseLong(transferredBytesStr); 
     long transferTime = Long.parseLong(transferTimeStr); 
     double transferRate = 0.0; 
     if (transferTime > 0) transferRate = ((transferredBytes) * 1000.0)/(transferTime * 1024.0); 
     Log.i(TAG, "Transfer rate: " + transferRate + " KB/s"); 
    } 
    catch (NumberFormatException e) 
    { 
     // Cannot parse string. 
    } 
    } 
} 
} 

建議我在哪裏做錯了。

Answer 1

我找到了一些東西給你。檢查此GoogleCode示例項目。它對我來說非常合適。他們與實施以下類的下載功能

DownloaderThread.java

public class DownloaderThread extends Thread 
{ 
    // constants 
    private static final int DOWNLOAD_BUFFER_SIZE = 4096; 

    // instance variables 
    private AndroidFileDownloader parentActivity; 
    private String downloadUrl; 

    /** 
    * Instantiates a new DownloaderThread object. 
    * @param parentActivity Reference to AndroidFileDownloader activity. 
    * @param inUrl String representing the URL of the file to be downloaded. 
    */ 
    public DownloaderThread(AndroidFileDownloader inParentActivity, String inUrl) 
    { 
     downloadUrl = ""; 
     if(inUrl != null) 
     { 
      downloadUrl = inUrl; 
     } 
     parentActivity = inParentActivity; 
    } 

    /** 
    * Connects to the URL of the file, begins the download, and notifies the 
    * AndroidFileDownloader activity of changes in state. Writes the file to 
    * the root of the SD card. 
    */ 
    @Override 
    public void run() 
    { 
     URL url; 
     URLConnection conn; 
     int fileSize, lastSlash; 
     String fileName; 
     BufferedInputStream inStream; 
     BufferedOutputStream outStream; 
     File outFile; 
     FileOutputStream fileStream; 
     Message msg; 

     // we're going to connect now 
     msg = Message.obtain(parentActivity.activityHandler, 
       AndroidFileDownloader.MESSAGE_CONNECTING_STARTED, 
       0, 0, downloadUrl); 
     parentActivity.activityHandler.sendMessage(msg); 

     try 
     { 
      url = new URL(downloadUrl); 
      conn = url.openConnection(); 
      conn.setUseCaches(false); 
      fileSize = conn.getContentLength(); 

      // get the filename 
      lastSlash = url.toString().lastIndexOf('/'); 
      fileName = "file.bin"; 
      if(lastSlash >=0) 
      { 
       fileName = url.toString().substring(lastSlash + 1); 
      } 
      if(fileName.equals("")) 
      { 
       fileName = "file.bin"; 
      } 

      // notify download start 
      int fileSizeInKB = fileSize/1024; 
      msg = Message.obtain(parentActivity.activityHandler, 
        AndroidFileDownloader.MESSAGE_DOWNLOAD_STARTED, 
        fileSizeInKB, 0, fileName); 
      parentActivity.activityHandler.sendMessage(msg); 

      // start download 
      inStream = new BufferedInputStream(conn.getInputStream()); 
      outFile = new File(Environment.getExternalStorageDirectory() + "/" + fileName); 
      fileStream = new FileOutputStream(outFile); 
      outStream = new BufferedOutputStream(fileStream, DOWNLOAD_BUFFER_SIZE); 
      byte[] data = new byte[DOWNLOAD_BUFFER_SIZE]; 
      int bytesRead = 0, totalRead = 0; 
      while(!isInterrupted() && (bytesRead = inStream.read(data, 0, data.length)) >= 0) 
      { 
       outStream.write(data, 0, bytesRead); 

       // update progress bar 
       totalRead += bytesRead; 
       int totalReadInKB = totalRead/1024; 
       msg = Message.obtain(parentActivity.activityHandler, 
         AndroidFileDownloader.MESSAGE_UPDATE_PROGRESS_BAR, 
         totalReadInKB, 0); 
       parentActivity.activityHandler.sendMessage(msg); 
      } 

      outStream.close(); 
      fileStream.close(); 
      inStream.close(); 

      if(isInterrupted()) 
      { 
       // the download was canceled, so let's delete the partially downloaded file 
       outFile.delete(); 
      } 
      else 
      { 
       // notify completion 
       msg = Message.obtain(parentActivity.activityHandler, 
         AndroidFileDownloader.MESSAGE_DOWNLOAD_COMPLETE); 
       parentActivity.activityHandler.sendMessage(msg); 
      } 
     } 
     catch(MalformedURLException e) 
     { 
      String errMsg = parentActivity.getString(R.string.error_message_bad_url); 
      msg = Message.obtain(parentActivity.activityHandler, 
        AndroidFileDownloader.MESSAGE_ENCOUNTERED_ERROR, 
        0, 0, errMsg); 
      parentActivity.activityHandler.sendMessage(msg); 
     } 
     catch(FileNotFoundException e) 
     { 
      String errMsg = parentActivity.getString(R.string.error_message_file_not_found); 
      msg = Message.obtain(parentActivity.activityHandler, 
        AndroidFileDownloader.MESSAGE_ENCOUNTERED_ERROR, 
        0, 0, errMsg); 
      parentActivity.activityHandler.sendMessage(msg); 
     } 
     catch(Exception e) 
     { 
      String errMsg = parentActivity.getString(R.string.error_message_general); 
      msg = Message.obtain(parentActivity.activityHandler, 
        AndroidFileDownloader.MESSAGE_ENCOUNTERED_ERROR, 
        0, 0, errMsg); 
      parentActivity.activityHandler.sendMessage(msg); 
     } 
    } 

} 

更新

或者你可以簡單地使用下面的代碼兩種Upload & Download過程。

package com.resource.util; 
import java.io.BufferedInputStream; 
import java.io.BufferedOutputStream; 
import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.net.MalformedURLException; 
import java.net.URL; 
import java.net.URLConnection; 

/** 
* This class is used to upload a file to a FTP server. 
* 
* @author Muthu 
*/ 
public class FileUpload 
{ 

    /** 
    * Upload a file to a FTP server. A FTP URL is generated with the 
    * following syntax: 
    * ftp://user:password@host:port/filePath;type=i. 
    * 
    * @param ftpServer , FTP server address (optional port ':portNumber'). 
    * @param user , Optional user name to login. 
    * @param password , Optional password for user. 
    * @param fileName , Destination file name on FTP server (with optional 
    *   preceding relative path, e.g. "myDir/myFile.txt"). 
    * @param source , Source file to upload. 
    * @throws MalformedURLException, IOException on error. 
    */ 
    public void upload(String ftpServer, String user, String password, 
     String fileName, File source) throws MalformedURLException, 
     IOException 
    { 
     if (ftpServer != null && fileName != null && source != null) 
     { 
     StringBuffer sb = new StringBuffer("ftp://"); 
     // check for authentication else assume its anonymous access. 
     if (user != null && password != null) 
     { 
      sb.append(user); 
      sb.append(':'); 
      sb.append(password); 
      sb.append('@'); 
     } 
     sb.append(ftpServer); 
     sb.append('/'); 
     sb.append(fileName); 
     /* 
      * type ==> a=ASCII mode, i=image (binary) mode, d= file directory 
      * listing 
      */ 
     sb.append(";type=i"); 

     BufferedInputStream bis = null; 
     BufferedOutputStream bos = null; 
     try 
     { 
      URL url = new URL(sb.toString()); 
      URLConnection urlc = url.openConnection(); 

      bos = new BufferedOutputStream(urlc.getOutputStream()); 
      bis = new BufferedInputStream(new FileInputStream(source)); 

      int i; 
      // read byte by byte until end of stream 
      while ((i = bis.read()) != -1) 
      { 
       bos.write(i); 
      } 
     } 
     finally 
     { 
      if (bis != null) 
       try 
       { 
        bis.close(); 
       } 
       catch (IOException ioe) 
       { 
        ioe.printStackTrace(); 
       } 
      if (bos != null) 
       try 
       { 
        bos.close(); 
       } 
       catch (IOException ioe) 
       { 
        ioe.printStackTrace(); 
       } 
     } 
     } 
     else 
     { 
     System.out.println("Input not available."); 
     } 
    } 

    /** 
    * Download a file from a FTP server. A FTP URL is generated with the 
    * following syntax: 
    * ftp://user:password@host:port/filePath;type=i. 
    * 
    * @param ftpServer , FTP server address (optional port ':portNumber'). 
    * @param user , Optional user name to login. 
    * @param password , Optional password for user. 
    * @param fileName , Name of file to download (with optional preceeding 
    *   relative path, e.g. one/two/three.txt). 
    * @param destination , Destination file to save. 
    * @throws MalformedURLException, IOException on error. 
    */ 
    public void download(String ftpServer, String user, String password, 
     String fileName, File destination) throws MalformedURLException, 
     IOException 
    { 
     if (ftpServer != null && fileName != null && destination != null) 
     { 
     StringBuffer sb = new StringBuffer("ftp://"); 
     // check for authentication else assume its anonymous access. 
     if (user != null && password != null) 
     { 
      sb.append(user); 
      sb.append(':'); 
      sb.append(password); 
      sb.append('@'); 
     } 
     sb.append(ftpServer); 
     sb.append('/'); 
     sb.append(fileName); 
     /* 
      * type ==> a=ASCII mode, i=image (binary) mode, d= file directory 
      * listing 
      */ 
     sb.append(";type=i"); 
     BufferedInputStream bis = null; 
     BufferedOutputStream bos = null; 
     try 
     { 
      URL url = new URL(sb.toString()); 
      URLConnection urlc = url.openConnection(); 

      bis = new BufferedInputStream(urlc.getInputStream()); 
      bos = new BufferedOutputStream(new FileOutputStream(
        destination.getName())); 

      int i; 
      while ((i = bis.read()) != -1) 
      { 
       bos.write(i); 
      } 
     } 
     finally 
     { 
      if (bis != null) 
       try 
       { 
        bis.close(); 
       } 
       catch (IOException ioe) 
       { 
        ioe.printStackTrace(); 
       } 
      if (bos != null) 
       try 
       { 
        bos.close(); 
       } 
       catch (IOException ioe) 
       { 
        ioe.printStackTrace(); 
       } 
     } 
     } 
     else 
     { 
     System.out.println("Input not available"); 
     } 
    } 
} 

從上面的代碼download()方法爲您提供任何您需要的。

Answer 2

我使用的庫Download Commons Net是其中的佼佼者，它的作品完美的上傳或下載