org.apache.crunch.SourceTarget Maven / Gradle / Ivy
/**
* 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.crunch;
import org.apache.hadoop.fs.FileSystem;
/**
* An interface for classes that implement both the {@code Source} and the
* {@code Target} interfaces.
*
*/
public interface SourceTarget extends Source, Target {
/**
* Adds the given key-value pair to the {@code Configuration} instance(s) that are used to
* read and write this {@code SourceTarget}. Allows for multiple inputs and outputs to
* re-use the same config keys with different values when necessary.
*/
SourceTarget conf(String key, String value);
/**
* Adds the {@code Configuration} of the given filesystem such that the source-target can read/write from/to it when
* the {@code Pipeline} itself does not have that configuration.
*
* Changing the filesystem after it is set is not supported and will result in {@link
* IllegalStateException}
*
* @param fileSystem the filesystem
* @return this SourceTarget
* @throws IllegalStateException if the filesystem has already been set
* @throws IllegalArgumentException if the source/target is pointing to a fully qualified Path in a different
* FileSystem
*/
SourceTarget fileSystem(FileSystem fileSystem);
}