How To Download A File/Plugin

So how would I go about downloading a file from a website? Like for instance a required plugin thats needed to work with my plugin. If thats not to confusing.
TL;DR-Need to download file into plugin folder.
Thanks Everyone!

 

chenr1
Wrong forum go to bukkit help

 

I would set up an input stream for the web. I am not really good with that stuff, but you should google 'input streams' 'output streams' and 'grabbing files from internet, java'

 

TheGreenGamerHD

That threw me off >:-(

 

Try using Java NIO and FileChannels.

Using transferFrom is potentially more efficient than a loop that reads from and writes to a channel. Many operating systems can transfer bytes directly from the source channel to the file system cache without copying them.

Code:

URL website = new URL("http://www.website.com/information.asp");
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream("information.html");
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);

The third parameter in transferFrom() is the maximum amount of bytes to transfer. Integer.Max_VALUE will transfer at most 2^31 bytes and Long.MAX_VALUE will allow at most 2^63 bytes.


And there's also this:

Code:

/**
  * Download.
  *
  * @param URL URL of the file to download
  * @param folder The folder to download it to (Relative or absolute path is acceptable)
  * @param name The new name of the file, leave null to use the filename in the URL.
  * @return true if succesful, false otherwise
  */
public static boolean download(String URL, String folder, String name) {
    if (folder == null) return false;
 
    if (name == null) {
          String[] list = URL.replace("\\", "/").split("/");
          name = list[list.length-1];
    }
 
    if (folder.endsWith("/"))
          folder = folder + name;
    else
          folder = folder + "/" + name;
 
    try {
          java.net.URL url = new java.net.URL(URL);
          java.net.HttpURLConnection connection = (java.net.HttpURLConnection)                              url.openConnection();
 
          float totalDataRead=0;
 
          java.io.BufferedInputStream in = new java.io.BufferedInputStream(connection.getInputStream());
          java.io.FileOutputStream fos = new java.io.FileOutputStream(new java.io.File(folder));
          java.io.BufferedOutputStream bout = new java.io.BufferedOutputStream(fos, 1024);
 
          byte[] data = new byte[1024];
          int i=0;
          while((i=in.read(data,0,1024))>=0) {
              totalDataRead=totalDataRead+i;
              bout.write(data,0,i);
          }
 
          bout.close();
          in.close();
          return true;
    } catch (Exception e) {
          return false;
    }
}

 

Thanks so much. But i get errors in eclipse. Do i have to surround in try catch?

 

chenr1
Yeah.
"URL website = new URL("http://www.website.com/information.asp");" throws a MalformedURLExcepion
"website.openStream()" throws an IOException
"FileOutputStream fos = new FileOutputStream("information.html");" throws a FileNotFoundException
and the transferFrom throws an IOException.

And the file in the FileOutputStream is the destination file, it can be a relative path, so just use something like "plugins/filename.jar".

And the FileOutputStream needs to be closed after the transferFrom