twill-common/src/main/java/org/apache/twill/filesystem/LocationFactories.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.apache.twill.filesystem;

import java.io.IOException;
import java.net.URI;

/**
 * Provides helper methods for creating different {@link LocationFactory}.
 */
public final class LocationFactories {

  /**
   * Creates a {@link LocationFactory} that always applies the giving namespace prefix.
   */
  public static LocationFactory namespace(LocationFactory delegate, final String namespace) {
    return new ForwardingLocationFactory(delegate) {
      @Override
      public Location create(String path) {
        try {
          Location base = getDelegate().create(namespace);
          return base.append(path);
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }

      @Override
      public Location create(URI uri) {
        if (uri.isAbsolute()) {
          return getDelegate().create(uri);
        }
        try {
          Location base = getDelegate().create(namespace);
          return base.append(uri.getPath());
        } catch (IOException e) {
          throw new RuntimeException(e);
        }
      }

      @Override
      public Location getHomeLocation() {
        return getDelegate().getHomeLocation();
      }
    };
  }

  private LocationFactories() {
  }
}