content: /*
   * 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 com.onegravity.rteditor.utils.validator;
  
  import java.io.Serializable;
  import java.util.regex.Pattern;
  import java.util.regex.Matcher;
  
  /**
   * <b>Regular Expression</b> validation (using JDK 1.4+ regex support).
   * <p>
   * Construct the validator either for a single regular expression or a set (array) of
   * regular expressions. By default validation is <i>case sensitive</i> but constructors
   * are provided to allow  <i>case in-sensitive</i> validation. For example to create
   * a validator which does <i>case in-sensitive</i> validation for a set of regular
   * expressions:
   * </p>
   * <pre>
   * <code>
   * String[] regexs = new String[] {...};
   * RegexValidator validator = new RegexValidator(regexs, false);
   * </code>
   * </pre>
   *
   * <ul>
   *   <li>Validate <code>true</code> or <code>false</code>:</li>
   *   <li>
   *     <ul>
   *       <li><code>boolean valid = validator.isValid(value);</code></li>
   *     </ul>
   *   </li>
   *   <li>Validate returning an aggregated String of the matched groups:</li>
   *   <li>
   *     <ul>
   *       <li><code>String result = validator.validate(value);</code></li>
   *     </ul>
   *   </li>
   *   <li>Validate returning the matched groups:</li>
   *   <li>
   *     <ul>
   *       <li><code>String[] result = validator.match(value);</code></li>
   *     </ul>
   *   </li>
   * </ul>
   *
   * <p>
   * Cached instances pre-compile and re-use {@link Pattern}(s) - which according
   * to the {@link Pattern} API are safe to use in a multi-threaded environment.
   * </p>
   *
   * @version $Revision: 1649191 $
   * @since Validator 1.4
   */
  public class RegexValidator implements Serializable {
  
      private static final long serialVersionUID = -8832409930574867162L;
  
      private final Pattern[] patterns;
  
      /**
       * Construct a <i>case sensitive</i> validator for a single
       * regular expression.
       *
       * @param regex The regular expression this validator will
       * validate against
       */
      public RegexValidator(String regex) {
          this(regex, true);
      }
  
      /**
       * Construct a validator for a single regular expression
       * with the specified case sensitivity.
       *
       * @param regex The regular expression this validator will
       * validate against
       * @param caseSensitive when <code>true</code> matching is <i>case
       * sensitive</i>, otherwise matching is <i>case in-sensitive</i>
       */
      public RegexValidator(String regex, boolean caseSensitive) {
          this(new String[] {regex}, caseSensitive);
      }
  
      /**
       * Construct a <i>case sensitive</i> validator that matches any one
       * of the set of regular expressions.
       *
       * @param regexs The set of regular expressions this validator will
       * validate against
       */
      public RegexValidator(String[] regexs) {
          this(regexs, true);
      }
  
      /**
       * Construct a validator that matches any one of the set of regular
       * expressions with the specified case sensitivity.
       *
       * @param regexs The set of regular expressions this validator will
       * validate against
       * @param caseSensitive when <code>true</code> matching is <i>case
       * sensitive</i>, otherwise matching is <i>case in-sensitive</i>
       */
      public RegexValidator(String[] regexs, boolean caseSensitive) {
          if (regexs == null || regexs.length == 0) {
              throw new IllegalArgumentException("Regular expressions are missing");
          }
          patterns = new Pattern[regexs.length];
          int flags =  (caseSensitive ? 0: Pattern.CASE_INSENSITIVE);
          for (int i = 0; i < regexs.length; i++) {
              if (regexs[i] == null || regexs[i].length() == 0) {
                  throw new IllegalArgumentException("Regular expression[" + i + "] is missing");
              }
              patterns[i] =  Pattern.compile(regexs[i], flags);
          }
      }
  
      /**
       * Validate a value against the set of regular expressions.
       *
       * @param value The value to validate.
       * @return <code>true</code> if the value is valid
       * otherwise <code>false</code>.
       */
      public boolean isValid(String value) {
          if (value == null) {
              return false;
          }
          for (int i = 0; i < patterns.length; i++) {
              if (patterns[i].matcher(value).matches()) {
                  return true;
              }
          }
          return false;
      }
  
      /**
       * Validate a value against the set of regular expressions
       * returning the array of matched groups.
       *
       * @param value The value to validate.
       * @return String array of the <i>groups</i> matched if
       * valid or <code>null</code> if invalid
       */
      public String[] match(String value) {
          if (value == null) {
              return null;
          }
          for (int i = 0; i < patterns.length; i++) {
              Matcher matcher = patterns[i].matcher(value);
              if (matcher.matches()) {
                  int count = matcher.groupCount();
                  String[] groups = new String[count];
                  for (int j = 0; j < count; j++) {
                      groups[j] = matcher.group(j+1);
                  }
                  return groups;
              }
          }
          return null;
      }
  
  
      /**
       * Validate a value against the set of regular expressions
       * returning a String value of the aggregated groups.
       *
       * @param value The value to validate.
       * @return Aggregated String value comprised of the
       * <i>groups</i> matched if valid or <code>null</code> if invalid
       */
      public String validate(String value) {
          if (value == null) {
              return null;
          }
          for (int i = 0; i < patterns.length; i++) {
              Matcher matcher = patterns[i].matcher(value);
              if (matcher.matches()) {
                  int count = matcher.groupCount();
                  if (count == 1) {
                      return matcher.group(1);
                  }
                  StringBuffer buffer = new StringBuffer();
                  for (int j = 0; j < count; j++) {
                      String component = matcher.group(j+1);
                      if (component != null) {
                          buffer.append(component);
                      }
                  }
                  return buffer.toString();
              }
          }
          return null;
      }
  
      /**
       * Provide a String representation of this validator.
       * @return A String representation of this validator
       */
      public String toString() {
          StringBuffer buffer = new StringBuffer();
          buffer.append("RegexValidator{");
          for (int i = 0; i < patterns.length; i++) {
              if (i > 0) {
                  buffer.append(",");
              }
              buffer.append(patterns[i].pattern());
          }
          buffer.append("}");
          return buffer.toString();
      }
  
  }
  