How to use

isUrl

method

in

htsjdk.samtools.util.IOUtil

/**
 * Checks that an input is  is non-null, a URL or a file, exists, 
 * and if its a file then it is not a directory and is readable.  If any
 * condition is false then a runtime exception is thrown.
 *
 * @param input the input to check for validity
 */
public static void assertInputIsValid(final String input) {
 if (input == null) {
  throw new IllegalArgumentException("Cannot check validity of null input.");
 }
 if (!isUrl(input)) {
  assertFileIsReadable(new File(input));
 }
}

/**
 * Checks that an input is  is non-null, a URL or a file, exists, 
 * and if its a file then it is not a directory and is readable.  If any
 * condition is false then a runtime exception is thrown.
 *
 * @param input the input to check for validity
 */
public static void assertInputIsValid(final String input) {
 if (input == null) {
  throw new IllegalArgumentException("Cannot check validity of null input.");
 }
 if (!isUrl(input)) {
  assertFileIsReadable(new File(input));
 }
}

else if(IOUtil.isUrl(file))