package jalview.util;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

public class HttpUtils
{

  /**
   * Returns true if it is possible to open an input stream at the given URL,
   * else false. The input stream is closed.
   * 
   * @param url
   * @return
   */
  public static boolean isValidUrl(String url)
  {
    InputStream is = null;
    try
    {
      is = new URL(url).openStream();
      if (is != null)
      {
        return true;
      }
    } catch (IOException x)
    {
      // MalformedURLException, FileNotFoundException
      return false;
    } finally
    {
      if (is != null)
      {
        try
        {
          is.close();
        } catch (IOException e)
        {
          // ignore
        }
      }
    }
    return false;
  }

}