cascading.tap.hadoop.Lfs.java Source code

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Here is the source code for cascading.tap.hadoop.Lfs.java

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/*
 * Copyright (c) 2007-2015 Concurrent, Inc. All Rights Reserved.
 *
 * Project and contact information: http://www.cascading.org/
 *
 * This file is part of the Cascading project.
 *
 * 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 cascading.tap.hadoop;

import java.beans.ConstructorProperties;
import java.io.IOException;

import cascading.scheme.Scheme;
import cascading.tap.SinkMode;
import cascading.tap.TapException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;

/**
 * Class Lfs is a {@link cascading.tap.Tap} class that provides access to the Local File System via Hadoop.
 * <p/>
 * Note that using a Lfs {@link cascading.tap.Tap} instance in a {@link cascading.flow.Flow} will force a portion of not the whole Flow to be executed
 * in "local" mode forcing the Flow to execute in the current JVM. Mixing with {@link cascading.tap.hadoop.Dfs} and other Tap
 * types is possible, providing a means to implement complex file/data management functions.
 * <p/>
 * Use {@link cascading.tap.hadoop.Hfs} if you need a Tap instance that inherits the default {@link FileSystem} used by Hadoop.
 */
public class Lfs extends Hfs {
    @ConstructorProperties({ "scheme" })
    Lfs(Scheme scheme) {
        super(scheme);
    }

    /**
     * Constructor Lfs creates a new Lfs instance.
     *
     * @param scheme     of type Scheme
     * @param stringPath of type String
     */
    @ConstructorProperties({ "scheme", "stringPath" })
    public Lfs(Scheme scheme, String stringPath) {
        super(scheme, stringPath);
    }

    /**
     * Constructor Lfs creates a new Lfs instance.
     *
     * @param scheme     of type Scheme
     * @param stringPath of type String
     * @param sinkMode   of type SinkMode
     */
    @ConstructorProperties({ "scheme", "stringPath", "sinkMode" })
    public Lfs(Scheme scheme, String stringPath, SinkMode sinkMode) {
        super(scheme, stringPath, sinkMode);
    }

    protected void setStringPath(String stringPath) {
        if (stringPath.matches(".*://.*") && !stringPath.startsWith("file://"))
            throw new IllegalArgumentException("uri must use the file scheme");

        super.setStringPath(stringPath);
    }

    @Override
    protected FileSystem getFileSystem(Configuration conf) {
        try {
            return FileSystem.getLocal(conf);
        } catch (IOException exception) {
            throw new TapException("unable to get handle to get local filesystem", exception);
        }
    }
}