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WisePersist AppConfig is a utility module which simplifies application configurations against different environments - test, dev, stage and prod.

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/*
 * Copyright (c) 2016 WisePersist.org
 *
 * 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 org.wisepersist.settings;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.Closeable;
import java.io.IOException;

/**
 * Resource manager to isolate the auto-closing logic in a separate class.
 *
 * @author [email protected]
 */
public class ResourceManager {

  private static final Logger log = LoggerFactory.getLogger(ResourceManager.class); //NOPMD

  private Closeable resource;

  /**
   * Default non-arg constructor.
   */
  public ResourceManager() {
    // Do nothing here
  }

  /**
   * Constructs a new {@link ResourceManager} instance with resource specified.
   *
   * @param theResource The resource specified.
   */
  private ResourceManager(final Closeable theResource) {
    this.resource = theResource;
  }

  /**
   * Creates a new instance of {@link ResourceManager} with the resource specified.
   *
   * @param theResource The closeable resource specified.
   * @return The new instance of {@link ResourceManager} created.
   */
  public final ResourceManager with(final Closeable theResource) {
    return new ResourceManager(theResource);
  }

  /**
   * Runs the resource handler.
   *
   * @param handler The resource handler specified.
   * @param  The result type specified.
   * @return The result of resource processing.
   * @throws IOException If IO errors occur.
   */
  public final  T run(final ResourceHandler handler) throws IOException {
    try {
      return handler.handle(resource);
    } finally {
      if (resource != null) {
        try {
          resource.close();
        } catch (final IOException ex) {
          log.error(ex.getMessage());
        }
      }
    }
  }
}