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 org.apache.cloudstack.acl;
  
  import com.cloud.exception.InvalidParameterValueException;
  
  import java.util.regex.Pattern;
  
  import org.apache.commons.lang3.StringUtils;
  
  public final class Rule {
      private final String rule;
      private final static Pattern ALLOWED_PATTERN = Pattern.compile("^[a-zA-Z0-9*]+$");
  
      public Rule(final String rule) {
          validate(rule);
          this.rule = rule;
      }
  
      public boolean matches(final String commandName) {
          return StringUtils.isNotEmpty(commandName)
                  && commandName.toLowerCase().matches(rule.toLowerCase().replace("*", "\\w*"));
      }
  
      public String getRuleString() {
          return rule;
      }
  
      @Override
      public String toString() {
          return rule;
      }
  
      private static boolean validate(final String rule) {
          if (StringUtils.isEmpty(rule) || !ALLOWED_PATTERN.matcher(rule).matches()) {
              throw new InvalidParameterValueException("Only API names and wildcards are allowed, invalid rule provided: " + rule);
          }
          return true;
      }
  }
  