DelegatingRepository.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.schemarepo;

import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Base class for all delegating repositories. Implements decorator pattern.
 */
public abstract class DelegatingRepository extends BaseRepository {

  protected final Repository repo;

  protected DelegatingRepository(final Repository delegate) {
    if (delegate == null) {
      throw new IllegalArgumentException("Delegate repository required");
    }
    this.repo = delegate;
  }

  @Override
  public void isValid() {
    if (repo instanceof BaseRepository) {
      ((BaseRepository)repo).isValid();
    }
  }

  @Override
  public Subject register(final String subjectName, final SubjectConfig config) {
    return repo.register(subjectName, config);
  }

  @Override
  public Subject lookup(final String subjectName) {
    return repo.lookup(subjectName);
  }

  @Override
  public Iterable<Subject> subjects() {
    return repo.subjects();
  }

  @Override
  public void close() throws IOException {
    repo.close();
  }

  @Override
  protected Map<String, String> exposeConfiguration() {
    final Map<String, String> properties = new LinkedHashMap<String, String>(super.exposeConfiguration());
    properties.put("DELEGATE", repo.toString());
    return properties;
  }

}