nl.kpmg.lcm.server.data.hdfs.HdfsFileSystemAdapter.java Source code

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Here is the source code for nl.kpmg.lcm.server.data.hdfs.HdfsFileSystemAdapter.java

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package nl.kpmg.lcm.server.data.hdfs;

import nl.kpmg.lcm.common.data.TestResult;
import nl.kpmg.lcm.server.backend.storage.HdfsFileStorage;
import nl.kpmg.lcm.server.data.FileSystemAdapter;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocatedFileStatus;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.RemoteIterator;

import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

/*
  * Copyright 2017 KPMG N.V. (unless otherwise stated).
  *
  * 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.
 */

/**
 *
 * @author shristov
 */
public class HdfsFileSystemAdapter implements FileSystemAdapter {
    private final HdfsFileStorage storage;

    public HdfsFileSystemAdapter(HdfsFileStorage storage) {
        this.storage = storage;
    }

    @Override
    public List listFileNames(String subPath) throws IOException {

        Configuration conf = new Configuration();
        conf.set("fs.defaultFS", storage.getUrl());
        FileSystem hdfs = FileSystem.get(conf);
        String storagePath = "/" + storage.getPath() + "/" + subPath;
        Path filePath = new Path(storagePath);
        if (!hdfs.exists(filePath)) {
            return null;
        }

        RemoteIterator<LocatedFileStatus> fileList = hdfs.listFiles(filePath, false);
        LinkedList<String> fileNameList = new LinkedList();

        while (fileList.hasNext()) {
            LocatedFileStatus fileStatus = fileList.next();
            fileNameList.add(fileStatus.getPath().getName());
        }

        return fileNameList;
    }

    @Override
    public TestResult testConnection() throws IOException {
        Configuration conf = new Configuration();
        conf.set("fs.defaultFS", storage.getUrl());
        FileSystem hdfs = FileSystem.get(conf);
        String storagePath = "/" + storage.getPath();
        Path filePath = new Path(storagePath);
        if (hdfs.exists(filePath)) {
            return new TestResult("OK", TestResult.TestCode.ACCESIBLE);
        }

        return new TestResult("Connection is successful but Storage path is not found!",
                TestResult.TestCode.INACCESSIBLE);
    }
}