android連接服務器下載文件工具類

    public static File downLoad(String serverPath,String savedPath,ProgressDialog dialog){

            try {


            URL url=new URL(serverPath);  
            HttpURLConnection _conn=(HttpURLConnection) url.openConnection();  
            _conn.setRequestMethod("GET");  
            _conn.setConnectTimeout(5000);  
            int code=_conn.getResponseCode();  
            if(code==200){  
                //設置進度條的長度  
                dialog.setMax(_conn.getContentLength());  
                InputStream is=_conn.getInputStream();  
                File _file=new File(savedPath);  
                FileOutputStream _FileOutputStream=new FileOutputStream(_file);  
                int len=0;  
                byte[] buffer= new byte[1024];  
                int _total=0;  
                while((len=is.read(buffer))!=-1){  
                    _FileOutputStream.write(buffer, 0,len);  
                    _total+=len;  
                    dialog.setProgress(_total);  
                    Thread.sleep(20);  
                }  
                _FileOutputStream.flush();  
                _FileOutputStream.close();  
                is.close();  
                return _file;  
            }else {  
                return null;  
            }  
        } catch (Exception e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
            return null;  
        }  


    }  </pre>