org.apache.sqoop.connector.hdfs.HdfsToInitializer.java Source code

Introduction

Here is the source code for org.apache.sqoop.connector.hdfs.HdfsToInitializer.java

Source

/**
 * 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.sqoop.connector.hdfs;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.log4j.Logger;
import org.apache.sqoop.common.SqoopException;
import org.apache.sqoop.connector.hdfs.configuration.LinkConfiguration;
import org.apache.sqoop.connector.hdfs.configuration.ToJobConfiguration;
import org.apache.sqoop.error.code.HdfsConnectorError;
import org.apache.sqoop.job.etl.Initializer;
import org.apache.sqoop.job.etl.InitializerContext;

import java.io.IOException;
import java.util.UUID;

public class HdfsToInitializer extends Initializer<LinkConfiguration, ToJobConfiguration> {

    private static final Logger LOG = Logger.getLogger(HdfsToInitializer.class);

    /**
     * {@inheritDoc}
     */
    @Override
    public void initialize(InitializerContext context, LinkConfiguration linkConfig, ToJobConfiguration jobConfig) {
        assert jobConfig != null;
        assert linkConfig != null;
        assert jobConfig.toJobConfig != null;
        assert jobConfig.toJobConfig.outputDirectory != null;

        Configuration configuration = HdfsUtils.createConfiguration(linkConfig);
        HdfsUtils.configurationToContext(configuration, context.getContext());
        boolean appendMode = Boolean.TRUE.equals(jobConfig.toJobConfig.appendMode);

        // Verification that given HDFS directory either don't exists or is empty
        try {
            FileSystem fs = FileSystem.get(configuration);
            Path path = new Path(jobConfig.toJobConfig.outputDirectory);

            if (fs.exists(path)) {
                if (fs.isFile(path)) {
                    throw new SqoopException(HdfsConnectorError.GENERIC_HDFS_CONNECTOR_0007,
                            "Output directory already exists and is a file");
                }

                if (fs.isDirectory(path) && !appendMode) {
                    FileStatus[] fileStatuses = fs.listStatus(path);
                    if (fileStatuses.length != 0) {
                        throw new SqoopException(HdfsConnectorError.GENERIC_HDFS_CONNECTOR_0007,
                                "Output directory is not empty");
                    }
                }
            }
        } catch (IOException e) {
            throw new SqoopException(HdfsConnectorError.GENERIC_HDFS_CONNECTOR_0007, "Unexpected exception", e);
        }

        // Building working directory
        String workingDirectory = jobConfig.toJobConfig.outputDirectory + "/." + UUID.randomUUID();
        LOG.info("Using working directory: " + workingDirectory);
        context.getContext().setString(HdfsConstants.WORK_DIRECTORY, workingDirectory);
    }
}