Download classes that support multiple file types in Android

  String directoryname = Environment.getexternalstoragedirectory (). toString ()                    + "/filename";////file save path// Incoming parameters: Context object, file save path; Downloadtask downloadtask = new Downloadtask (this, Mdownloadurl, directoryname);        New Thread (Downloadtask). Start ();///////start thread for download

Download class public class Downloadtask implements Runnable {private long mdownloadedsize = 0;   Private long mtotalsize;private int mdownloadpercent;    Private String Mlocalpath;    Private String Murl;   Private Context Mcontext;        Public Downloadtask (context context, string URL, string localPath) {This.mlocalpath = LocalPath;        This.murl = URL;    This.mcontext = context;    } @Override public void Run () {download ();        };////Download Method protected Boolean download () {File File = new file (Mlocalpath);        if (file.exists ()) {mdownloadedsize = File.length ();        } else {mdownloadedsize = 0;        } log.d (TAG, "Murl," + Murl + "downloadedsize," + mdownloadedsize);        HttpURLConnection httpconnection = null;        URL url = null;            try {url = new URL (mupgradeurl);            Httpconnection = (httpurlconnection) url.openconnection ();    Mtotalsize = Httpconnection.getcontentlength ();        LOG.D (TAG, "totalsize," + mtotalsize);            if (mdownloadedsize = = mtotalsize) {////////has been downloaded to local return true;                } else if (Mdownloadedsize > Mtotalsize) {if (!file.delete ()) {return false;        }} httpconnection.disconnect ();            } catch (Exception e) {e.printstacktrace ();        return false;                } finally {try {if (httpconnection! = null) {httpconnection.disconnect ();        }} catch (Exception e) {}} InputStream instream = null;        Randomaccessfile randomaccessfile = null;            try {httpconnection = (httpurlconnection) url.openconnection (); Httpconnection.setrequestproperty ("Accept", "image/gif," + "image/jpeg," + "image/pjpeg," + "image/p             JPEG, "+" Application/x-shockwave-flash, "       + "Application/xaml+xml," + "application/vnd.ms-xpsdocument," + "application/x-ms-xbap," + "a                    Pplication/x-ms-application, "+" application/vnd.ms-excel, "+" Application/vnd.ms-powerpoint, "            + "Application/msword," + "*/*");            Httpconnection.setrequestproperty ("Accept-language", "ZH-CN");            Httpconnection.setrequestproperty ("Referer", Mupgradeurl);            Httpconnection.setrequestproperty ("Charset", "UTF-8");            Httpconnection.setrequestproperty ("Range", "bytes=" + mdownloadedsize + "-");            Httpconnection.setrequestproperty ("Connection", "keep-alive");            Instream = Httpconnection.getinputstream ();            File SaveFile = new file (Mlocalpath);            Randomaccessfile = new Randomaccessfile (SaveFile, "RWD");            Randomaccessfile.seek (mdownloadedsize);            int offset = 0;            int count = 0;  int perunit = (int) mtotalsize/1024/100;          byte[] buffer = new byte[1024];                while (offset = instream.read (buffer, 0, 1024x768)! =-1) {randomaccessfile.write (buffer, 0, offset);                count++; if (count = = Perunit && mdownloadedsize < mtotalsize) {mdownloadpercent = (int) (Mdownloade                   Dsize * 100/mtotalsize);                Download hundred mdownloadpercent count = 0;            } mdownloadedsize + = offset; } if (mdownloadedsize = = mtotalsize) {/////////Download complete} log.d (TAG, "download            Finished. ");        return true;            } catch (Exception e) {e.printstacktrace ();        return false;                } finally {try {if (instream! = null) {instream.close ();                } if (httpconnection! = null) {httpconnection.disconnect ();         }       if (randomaccessfile! = null) {randomaccessfile.close (); }} catch (Exception e) {}}}}