getdown/src/getdown/core/src/main/java/com/threerings/getdown/net/HTTPDownloader.java

   1 //
   2 // Getdown - application installer, patcher and launcher
   3 // Copyright (C) 2004-2018 Getdown authors
   4 // https://github.com/threerings/getdown/blob/master/LICENSE
   5
   6 package com.threerings.getdown.net;
   7
   8 import java.io.File;
   9 import java.io.FileOutputStream;
  10 import java.io.IOException;
  11 import java.io.InputStream;
  12 import java.net.HttpURLConnection;
  13 import java.net.Proxy;
  14 import java.net.URL;
  15 import java.net.URLConnection;
  16 import java.nio.channels.Channels;
  17 import java.nio.channels.ReadableByteChannel;
  18
  19 import com.threerings.getdown.data.Resource;
  20 import com.threerings.getdown.util.ConnectionUtil;
  21
  22 import static com.threerings.getdown.Log.log;
  23
  24 /**
  25  * Implements downloading files over HTTP
  26  */
  27 public class HTTPDownloader extends Downloader
  28 {
  29     public HTTPDownloader (Proxy proxy)
  30     {
  31         _proxy = proxy;
  32     }
  33
  34     @Override protected long checkSize (Resource rsrc) throws IOException
  35     {
  36         URLConnection conn = ConnectionUtil.open(_proxy, rsrc.getRemote(), 0, 0);
  37         try {
  38             // if we're accessing our data via HTTP, we only need a HEAD request
  39             if (conn instanceof HttpURLConnection) {
  40                 HttpURLConnection hcon = (HttpURLConnection)conn;
  41                 hcon.setRequestMethod("HEAD");
  42                 hcon.connect();
  43                 // make sure we got a satisfactory response code
  44                 if (hcon.getResponseCode() != HttpURLConnection.HTTP_OK) {
  45                     throw new IOException("Unable to check up-to-date for " +
  46                                           rsrc.getRemote() + ": " + hcon.getResponseCode());
  47                 }
  48             }
  49             return conn.getContentLength();
  50
  51         } finally {
  52             // let it be known that we're done with this connection
  53             conn.getInputStream().close();
  54         }
  55     }
  56
  57     @Override protected void download (Resource rsrc) throws IOException
  58     {
  59         // TODO: make FileChannel download impl (below) robust and allow apps to opt-into it via a
  60         // system property
  61         if (true) {
  62             // download the resource from the specified URL
  63             URLConnection conn = ConnectionUtil.open(_proxy, rsrc.getRemote(), 0, 0);
  64             conn.connect();
  65
  66             // make sure we got a satisfactory response code
  67             if (conn instanceof HttpURLConnection) {
  68                 HttpURLConnection hcon = (HttpURLConnection)conn;
  69                 if (hcon.getResponseCode() != HttpURLConnection.HTTP_OK) {
  70                     throw new IOException("Unable to download resource " + rsrc.getRemote() + ": " +
  71                                           hcon.getResponseCode());
  72                 }
  73             }
  74             long actualSize = conn.getContentLength();
  75             log.info("Downloading resource", "url", rsrc.getRemote(), "size", actualSize);
  76             long currentSize = 0L;
  77             byte[] buffer = new byte[4*4096];
  78             try (InputStream in = conn.getInputStream();
  79                  FileOutputStream out = new FileOutputStream(rsrc.getLocalNew())) {
  80
  81                 // TODO: look to see if we have a download info file
  82                 // containing info on potentially partially downloaded data;
  83                 // if so, use a "Range: bytes=HAVE-" header.
  84
  85                 // read in the file data
  86                 int read;
  87                 while ((read = in.read(buffer)) != -1) {
  88                     // abort the download if the downloader is aborted
  89                     if (_state == State.ABORTED) {
  90                         break;
  91                     }
  92                     // write it out to our local copy
  93                     out.write(buffer, 0, read);
  94                     // note that we've downloaded some data
  95                     currentSize += read;
  96                     reportProgress(rsrc, currentSize, actualSize);
  97                 }
  98             }
  99
 100         } else {
 101             log.info("Downloading resource", "url", rsrc.getRemote(), "size", "unknown");
 102             File localNew = rsrc.getLocalNew();
 103             try (ReadableByteChannel rbc = Channels.newChannel(rsrc.getRemote().openStream());
 104                  FileOutputStream fos = new FileOutputStream(localNew)) {
 105                 // TODO: more work is needed here, transferFrom can fail to transfer the entire
 106                 // file, in which case it's not clear what we're supposed to do.. call it again?
 107                 // will it repeatedly fail?
 108                 fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
 109                 reportProgress(rsrc, localNew.length(), localNew.length());
 110             }
 111         }
 112     }
 113
 114     protected final Proxy _proxy;
 115 }