/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF 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.apache.commons.cli2.validation;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.List;

 import java.util.ListIterator;

 import org.apache.commons.cli2.resource.ResourceConstants;

 import org.apache.commons.cli2.resource.ResourceHelper;

 /**

  * The <code>UrlValidator</code> validates the string argument

  * values are URLs.  If the value is a URL, the string value in

  * the {@link java.util.List} of values is replaced with the

  * {@link java.net.URL} instance.

  *

  * URLs can also be validated based on their scheme by using

  * the {@link #setProtocol setProtocol} method, or by using the specified

  * {@link #UrlValidator(java.lang.String) constructor}.

  *

  * The following example shows how to limit the valid values

  * for the site argument to 'https' URLs.

  *

  * <pre>

  * ...

  * ArgumentBuilder builder = new ArgumentBuilder();

  * Argument site =

  *     builder.withName("site");

  *            .withValidator(new URLValidator("https"));

  * </pre>

  *

  * @author Rob Oxspring

  * @author John Keyes

  */

 public class UrlValidator implements Validator {

     /** allowed protocol */

     private String protocol = null;

     /**

      * Creates a UrlValidator.

      */

     public UrlValidator() {

     }

     /**

      * Creates a UrlValidator for the specified protocol.

      * @param protocol the protocol to be used

      */

     public UrlValidator(final String protocol) {

         setProtocol(protocol);

     }

     /**

      * Validate the list of values against the list of permitted values.

      * If a value is valid, replace the string in the <code>values</code>

      * {@link java.util.List} with the { java.net.URL} instance.

      *

      * @see org.apache.commons.cli2.validation.Validator#validate(java.util.List)

      */

     public void validate(final List values)

         throws InvalidArgumentException {

         for (final ListIterator i = values.listIterator(); i.hasNext();) {

             final String name = (String) i.next();

             try {

                 final URL url = new URL(name);

                 if ((protocol != null) && !protocol.equals(url.getProtocol())) {

                     throw new InvalidArgumentException(name);

                 }

                 i.set(url);

             } catch (final MalformedURLException mue) {

                 throw new InvalidArgumentException(ResourceHelper.getResourceHelper().getMessage(ResourceConstants.URLVALIDATOR_MALFORMED_URL,

                                                                                                  new Object[] {

                                                                                                      name

                                                                                                  }));

             }

         }

     }

     /**

      * Returns the protocol that must be used by a valid URL.

      *

      * @return the protocol that must be used by a valid URL.

      */

     public String getProtocol() {

         return protocol;

     }

     /**

      * Specifies the protocol that a URL must have to be valid.

      *

      * @param protocol the protocol that a URL must have to be valid.

      */

     public void setProtocol(String protocol) {

         this.protocol = protocol;

     }

 }