code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.net;
  
  import java.io.IOException;
  import java.io.UncheckedIOException;
  import java.io.UnsupportedEncodingException;
  import java.net.MalformedURLException;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.net.URL;
  import java.net.URLEncoder;
  import java.util.regex.Pattern;
  import org.openqa.selenium.internal.Require;
  
  public class Urls {
  
    private Urls() {
      // Utility class
    }
  
    /**
     * Encodes the text as an URL using UTF-8.
     *
     * @param value the text too encode
     * @return the encoded URI string
     * @see URLEncoder#encode(java.lang.String, java.lang.String)
     */
    public static String urlEncode(String value) {
      try {
        return URLEncoder.encode(value, "UTF-8");
      } catch (UnsupportedEncodingException e) {
        throw new UncheckedIOException(e);
      }
    }
  
    public static URL fromUri(URI uri) {
      try {
        return uri.toURL();
      } catch (MalformedURLException e) {
        throw new UncheckedIOException(e);
      }
    }
  
    /**
     * Convert a string, which may just be a hostname, into a valid {@link URI}. If no scheme is
     * given, it is set to {@code http} by default.
     *
     * <p>We prefer to use {@code URI} instead of {@code URL} since the latter requires a scheme
     * handler to be registered for types, so strings like {@code docker://localhost:1234} would not
     * generally be a valid {@link URL} but would be a correct {@link URI}.
     *
     * <p>A known limitation is that URI fragments are not handled. In the expected use cases for this
     * method, that is not a problem.
     */
    public static URI from(String rawUri) {
      Require.nonNull("URL to convert", rawUri);
      try {
        // Things to consider:
        // * A plain string hostname
        // * A host represented as an IPv4 address
        // * A host represented as an IPv6 address
        // * A host represented as an abbreviated IPv6 address
  
        // If there's no colon, then we have a plain hostname
        int colonIndex = rawUri.indexOf(':');
        int slashIndex = rawUri.indexOf('/');
        if (slashIndex == -1 && colonIndex == -1) {
          return createHttpUri(rawUri);
        }
  
        // Check the characters preceding the colon. If they're all numbers
        // (or there's no preceding character), we're dealing with a short form
        // ip6 address.
        if (colonIndex != -1) {
          if (colonIndex == 0) {
            return createHttpUri(rawUri);
          }
  
          if (Pattern.matches("\\d+", rawUri.substring(0, colonIndex))) {
            return createHttpUri(rawUri);
          }
        }
  
        // If there's a slash immediately after the colon, that's a scheme
        // and we can just create a URI from that.
        return new URI(rawUri);
      } catch (URISyntaxException e) {
        throw new UncheckedIOException(new IOException(e));
      }
    }
  
    private static URI createHttpUri(String rawHost) {
      int slashIndex = rawHost.indexOf('/');
      String host = slashIndex == -1 ? rawHost : rawHost.substring(0, slashIndex);
      String path = slashIndex == -1 ? null : rawHost.substring(slashIndex);
  
      try {
        return new URI("http", host, path, null);
      } catch (URISyntaxException e) {
        throw new UncheckedIOException(new IOException(e));
      }
    }
  }
  