001/*
002 * JPPF.
003 * Copyright (C) 2005-2018 JPPF Team.
004 * http://www.jppf.org
005 *
006 * Licensed under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.jppf.node.policy;
020
021import java.util.List;
022
023import org.jppf.utils.PropertiesCollection;
024
025/**
026 * A policy which evaluates a set of policies ordered by preference.
027 * @author Laurent Cohen
028 */
029public class Preference extends LogicalRule {
030  /**
031   * Explicit serialVersionUID.
032   */
033  private static final long serialVersionUID = 1L;
034
035  /**
036   * Initialize this policy with the specified array of children polices.
037   * @param policies the polcies in order of preference.
038   */
039  public Preference(final ExecutionPolicy... policies) {
040    super(policies);
041    if ((policies == null) || (policies.length == 0)) throw new IllegalArgumentException("there must be at least one policy in the list");
042  }
043
044  /**
045   * Initialize this policy with the specified array of children polices.
046   * @param policies the polcies in order of preference.
047   */
048  public Preference(final List<ExecutionPolicy> policies) {
049    super(policies.toArray(new ExecutionPolicy[policies.size()]));
050    if (policies.isEmpty()) throw new IllegalArgumentException("there must be at least one policy in the list");
051  }
052
053  @Override
054  public boolean accepts(final PropertiesCollection<String> info) {
055    for (ExecutionPolicy policy: children) {
056      if ((policy == null) || policy.evaluate(info)) return true;
057    }
058    return false;
059  }
060
061  @Override
062  public String toString(final int n) {
063    return new StringBuilder().append(indent(n)).append("<Preference>\n").append(super.toString(n)).append(indent(n)).append("</Preference>\n").toString();
064  }
065}