com.openpojo.random.generator.time.ZoneIdRandomGenerator Maven / Gradle / Ivy

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/*
 * Copyright (c) 2010-2018 Osman Shoukry
 *
 * 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 com.openpojo.random.generator.time;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Random;
import java.util.Set;

import com.openpojo.random.RandomGenerator;
import com.openpojo.reflection.java.load.ClassUtil;

import static com.openpojo.random.generator.time.util.ReflectionHelper.getMethod;
import static com.openpojo.random.generator.time.util.ReflectionHelper.invokeMethod;

/**
 * @author oshoukry
 */
public class ZoneIdRandomGenerator implements RandomGenerator {
  private static final String TYPE = "java.time.ZoneId";
  private static final ZoneIdRandomGenerator INSTANCE = new ZoneIdRandomGenerator();
  private static final Random RANDOM = new Random(System.currentTimeMillis());
  private final Class zoneIdClass;

  public static ZoneIdRandomGenerator getInstance() {
    return INSTANCE;
  }

  public Collection> getTypes() {
    List> types = new ArrayList>();
    if (zoneIdClass != null)
      types.add(zoneIdClass);
    return types;
  }

  public Object doGenerate(Class type) {
    Object[] availableZoneIds = getAvailableZones();
    return getZoneIdOf(availableZoneIds[RANDOM.nextInt(availableZoneIds.length)].toString());
  }

  @SuppressWarnings("unchecked")
  private Object[] getAvailableZones() {
    Method getAvailableZoneIdsMethod = getMethod(zoneIdClass, "getAvailableZoneIds");
    return ((Set) invokeMethod(getAvailableZoneIdsMethod, null)).toArray();
  }

  private Object getZoneIdOf(String availableZone) {
    Method ofMethod = getMethod(zoneIdClass, "of", String.class);
    return invokeMethod(ofMethod, null, availableZone);
  }

  private ZoneIdRandomGenerator() {
    zoneIdClass = ClassUtil.loadClass(TYPE);
  }
}