从服务器下载文件的方法

public static void downFile(String url,Context cxt) throws Exception{		
		HttpClient client=new DefaultHttpClient();
		HttpPost post=new HttpPost(url);
		InputStream res=null;
		BufferedOutputStream bos = null;
		BufferedInputStream bis=null;
		ZipInputStream zis=null;
		ZipEntry entry=null;
		HttpEntity entity=null;
		try{
		HttpResponse response = client.execute(post);
		if(response.getStatusLine().getStatusCode()==HttpStatus.SC_OK){
			entity= response.getEntity(); 
			res=entity.getContent();
		}		
			FileUtils.deleteFiles(cxt.getFilesDir());			
			bis = new BufferedInputStream(res);			
			zis= new ZipInputStream(bis);			
			while ((entry = zis.getNextEntry()) != null) {
					int count;
					byte data[] = new byte[2048];				
					bos = new BufferedOutputStream(cxt.openFileOutput(entry.getName(), Context.MODE_WORLD_READABLE|Context.MODE_WORLD_WRITEABLE));
					while ((count = zis.read(data)) != -1) {
						bos.write(data, 0, count);
					}
					bos.flush();
					data=null;
		    }   
		}catch(Exception ex){			
			ex.printStackTrace();
		}finally{
			Log.e("downFile", "downFile_finally");
			zis.close();
		    bis.close();
		    bos.close();
		    res.close();
			entity.consumeContent();
			client.getConnectionManager().shutdown();
		    entry=null;
		    zis=null;
		    bis=null;
		    bos=null;	 
			client=null;
			post=null;
			cxt=null;
		}
	}