A cleaner dependency manager for Bukkit plugins.

PluginDownloader.java

public class PluginDownloader {

    public boolean exists(String path) {
        try {
            HttpURLConnection urlConn = (HttpURLConnection) new URL(path).openConnection();
            urlConn.setConnectTimeout(1000 * 10);
            urlConn.connect();
            return urlConn.getResponseCode() == HttpURLConnection.HTTP_OK;
        } catch (MalformedURLException e) {
            System.err.println("The URL given <" + path + "> was not found!");
        } catch (IOException e) {
            e.printStackTrace();
        }
        return false;
    }

    public void downloadZip(URL from, String to) {
        try {
            BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(to));
            ZipInputStream zin = new ZipInputStream(from.openConnection().getInputStream());
  		byte[] buffer = new byte[65536];
            while ((ZipEntry ze = zin.getNextEntry()) != null) {
                while ((int read = zin.read(buffer)) != -1)
                    out.write(buffer, 0, read);
                zin.closeEntry();
            }
            System.out.println("The file at <" + from + "> was downloaded to the path <" + to + ">.");
			File base = new File(to);
            for (File file : base.listFiles()) 
                if (file.getName().endsWith(".jar"))
                    Bukkit.getPluginManager().loadPlugin(file);
        } catch (MalformedURLException e) {
            System.err.println("The URL given <" + from + "> was not found!");
        } catch (FileNotFoundException e) {
            System.err.println("The file path given <" + to + "> was not found!");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
			try {
				zin.close();
				out.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
        }
    }

    public void downloadJar(URL from, String to) {
        try {
            BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(to));
            InputStream in = from.openConnection().getInputStream();
			byte[] buffer = new byte[65536];
            while ((int read = in.read(buffer)) != -1)
                out.write(buffer, 0, read);
            System.out.println("The file at <" + from + "> was downloaded to the path <" + to + ">.");
			Bukkit.getPluginManager().loadPlugin(new File(to));
        } catch (MalformedURLException e) {
            System.err.println("The URL given <" + from + "> was not found!");
        } catch (FileNotFoundException e) {
            System.err.println("The file path given <" + to + "> was not found!");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
			try {
				out.close();
				in.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
        }
    }
}