Scope.java

/*
 * Copyright © 2014 Cask Data, Inc.
 *
 * Licensed 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 co.cask.cdap.api.common;

import java.util.HashMap;
import java.util.Map;

/**
 * Enum for the different types of scopes.
 */
public enum Scope {
  DATASET("dataset"),
  MAPREDUCE("mapreduce"),
  SPARK("spark");

  private final String displayName;

  /**
   * Private constructor to force using the enum values.
   */
  private Scope(String name) {
    displayName = name;
  }

  @Override
  public String toString() {
    return displayName;
  }

  // helper map for efficient implementation of scopeFor()
  private static final Map<String, Scope> LOOKUP_BY_DISPLAY_NAME;
  static {
    LOOKUP_BY_DISPLAY_NAME = new HashMap<>();
    for (Scope scope : Scope.values()) {
      LOOKUP_BY_DISPLAY_NAME.put(scope.toString(), scope);
    }
  }

  /**
   * @return the Scope represented by a display name.
   */
  public static Scope scopeFor(String displayName) {
    Scope scope = LOOKUP_BY_DISPLAY_NAME.get(displayName);
    if (scope != null) {
      return scope;
    }
    throw new IllegalArgumentException("Illegal scope name: " + displayName);
  }
}