我给你找到了一些东西。检查这个GoogleCode示例项目。它非常适合我。他们正在用下面的类实现下载功能
下载线程.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
或者您可以简单地将以下代码用于Upload&Download过程。
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" );
}
}
}
从上面的代码download()方法可以为您提供所需的任何内容。