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'rapiddweller Common' is an open source Java library forked from Databene Commons by Volker Bergmann. It provides extensions to the Java core library by utility classes, abstract concepts and concrete implementations.

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/*
 * Copyright (C) 2004-2015 Volker Bergmann ([email protected]).
 * All rights reserved.
 *
 * 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.rapiddweller.common.converter;

import com.rapiddweller.common.ArrayUtil;
import com.rapiddweller.common.BeanUtil;

import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.Collection;

/**
 * Converts arrays and collections to arrays and other object to an array of size 1.
 * Note: The target type is not declared Object[], since we also want to create byte[].
 * Created: 26.08.2007 16:01:38
 *
 * @author Volker Bergmann
 */
@SuppressWarnings({"unchecked", "rawtypes"})
public class ToArrayConverter extends ThreadSafeConverter {

  private final Class componentType;
  private boolean nullToEmpty;

  // constructors ----------------------------------------------------------------------------------------------------

  /**
   * Instantiates a new To array converter.
   */
  public ToArrayConverter() {
    this(Object.class);
  }

  /**
   * Instantiates a new To array converter.
   *
   * @param componentType the component type
   */
  public ToArrayConverter(Class componentType) {
    this(componentType, true);
  }

  /**
   * Instantiates a new To array converter.
   *
   * @param componentType the component type
   * @param nullToEmpty   the null to empty
   */
  public ToArrayConverter(Class componentType, boolean nullToEmpty) {
    super(Object.class, ArrayUtil.arrayType(componentType));
    this.componentType = componentType;
    this.nullToEmpty = nullToEmpty;
  }

  // properties ------------------------------------------------------------------------------------------------------

  /**
   * Sets null to empty.
   *
   * @param nullToEmpty the null to empty
   */
  public void setNullToEmpty(boolean nullToEmpty) {
    this.nullToEmpty = nullToEmpty;
  }

  // Converter interface implementation ------------------------------------------------------------------------------

  @Override
  public Object convert(Object sourceValue) {
    return convert(sourceValue, componentType, nullToEmpty);
  }

  // static utility methods ------------------------------------------------------------------------------------------

  /**
   * Convert object.
   *
   * @param sourceValue   the source value
   * @param componentType the component type
   * @return the object
   */
  public static Object convert(Object sourceValue, Class componentType) {
    return convert(sourceValue, componentType, true);
  }

  /**
   * Convert object.
   *
   * @param sourceValue   the source value
   * @param componentType the component type
   * @param nullToEmpty   the null to empty
   * @return the object
   */
  @SuppressWarnings("cast")
  public static Object convert(Object sourceValue, Class componentType, boolean nullToEmpty) {
    if (sourceValue == null) {
      return (nullToEmpty ? ArrayUtil.buildArrayOfType(componentType) : null);
    }
    if (sourceValue instanceof Collection) {
      Collection col = (Collection) sourceValue;
      Object[] array = (Object[]) Array.newInstance(componentType, col.size());
      int count = 0;
      for (Object item : col) {
        array[count++] = item;
      }
      return array;
    } else if (componentType == byte.class) {
      Method method = BeanUtil.getMethod(sourceValue.getClass(), "getBytes");
      if (method != null) {
        return BeanUtil.invoke(sourceValue, method, null);
      } else {
        throw new UnsupportedOperationException("Conversion not supported: " + sourceValue.getClass() + " -> " + componentType + "[]");
      }
    } else if (sourceValue.getClass().isArray()) {
      return ArrayUtil.buildArrayOfType(componentType, (Object[]) sourceValue);
    } else {
      return ArrayUtil.buildArrayOfType(componentType, sourceValue);
    }
  }

  @Override
  public String toString() {
    return getClass().getSimpleName() + "(" + componentType + ")";
  }

}