Java: Common way to validate and convert “host:port” to InetSocketAddress?

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I myself propose one possible workaround solution.

Convert a string into URI (this would validate it automatically) and then query the URI’s host and port components.

Sadly, an URI with a host component MUST have a scheme. This is why this solution is “not perfect”.

String string = ... // some string which has to be validated

try {
  // WORKAROUND: add any scheme to make the resulting URI valid.
  URI uri = new URI("my://" + string); // may throw URISyntaxException
  String host = uri.getHost();
  int port = uri.getPort();

  if (uri.getHost() == null || uri.getPort() == -1) {
    throw new URISyntaxException(uri.toString(),
      "URI must have host and port parts");
  }

  // here, additional checks can be performed, such as
  // presence of path, query, fragment, ...


  // validation succeeded
  return new InetSocketAddress (host, port);

} catch (URISyntaxException ex) {
  // validation failed
}

This solution needs no custom string parsing, works with IPv4 (1.1.1.1:123), IPv6 ([::0]:123) and host names (my.host.com:123).

Accidentally, this solution is well suited for my scenario. I was going to use URI schemes anyway.

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