com.trovit.hdfstree.fsinspectors.HDFSInspector.java Source code

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Here is the source code for com.trovit.hdfstree.fsinspectors.HDFSInspector.java

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/**
 *  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 com.trovit.hdfstree.fsinspectors;

import com.google.common.collect.Lists;
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 java.io.IOException;
import java.util.List;

public class HDFSInspector implements FSInspector {
    FileSystem fs;

    public HDFSInspector() {
        try {
            Configuration conf = getHadoopConf();
            fs = FileSystem.get(conf);
        } catch (Exception e) {
            System.out.println(e.getMessage());
            System.exit(1);
        }
    }

    @Override
    public boolean isDirectory(String path) {
        boolean isDir = false;
        try {
            isDir = fs.getFileStatus(new Path(path)).isDir();
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
        return isDir;
    }

    @Override
    public List<String> list(String currentPath) {
        List<String> subfiles = Lists.newArrayList();
        try {
            for (FileStatus fileStatus : fs.listStatus(new Path(currentPath))) {
                subfiles.add(fileStatus.getPath().getName());
            }
        } catch (IOException e) {
            System.out.println(e.getMessage());
        }
        return subfiles;
    }

    @Override
    public String addSubdirToCurrent(String path, String subdir) {
        Path current = new Path(path, subdir);
        return current.toString();
    }

    @Override
    public long getFileSize(String file) {
        Path current = new Path(file);
        try {
            return fs.getFileStatus(current).getLen();
        } catch (IOException e) {
            System.out.println("Cannot read file: " + current.toString());
            return 0;
        }
    }

    private Configuration getHadoopConf() throws Exception {
        Configuration conf = new Configuration();
        String hadoop_home = System.getenv("HADOOP_HOME");
        if (hadoop_home == null) {
            throw new Exception("HADOOP_HOME is not defined in the system.");
        }
        conf.addResource(new Path(hadoop_home + "/conf/hdfs-site.xml"));
        conf.addResource(new Path(hadoop_home + "/conf/mapred-site.xml"));
        conf.addResource(new Path(hadoop_home + "/conf/core-site.xml"));
        return conf;
    }
}