org.apache.ambari.fast_hdfs_resource.Runner.java Source code

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Here is the source code for org.apache.ambari.fast_hdfs_resource.Runner.java

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/**
 * 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.ambari.fast_hdfs_resource;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;

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

import com.google.gson.Gson;

public class Runner {
    public static void main(String[] args) throws IOException, URISyntaxException {
        // 1 - Check arguments
        if (args.length != 1) {
            System.err.println(
                    "Incorrect number of arguments. Please provide:\n" + "1) Path to json file\n" + "Exiting...");
            System.exit(1);
        }

        // 2 - Check if json-file exists
        final String jsonFilePath = args[0];
        File file = new File(jsonFilePath);

        if (!file.isFile()) {
            System.err.println("File " + jsonFilePath + " doesn't exist.\nExiting...");
            System.exit(1);
        }

        Gson gson = new Gson();
        Resource[] resources = null;
        FileSystem dfs = null;

        try {
            Configuration conf = new Configuration();
            dfs = FileSystem.get(conf);

            // 3 - Load data from JSON
            resources = (Resource[]) gson.fromJson(new FileReader(jsonFilePath), Resource[].class);

            // 4 - Connect to HDFS
            System.out.println("Using filesystem uri: " + FileSystem.getDefaultUri(conf).toString());
            dfs.initialize(FileSystem.getDefaultUri(conf), conf);

            for (Resource resource : resources) {
                System.out.println("Creating: " + resource);

                Resource.checkResourceParameters(resource, dfs);

                Path pathHadoop = new Path(resource.getTarget());
                if (!resource.isManageIfExists() && dfs.exists(pathHadoop)) {
                    System.out.println("Skipping the operation for not managed DFS directory "
                            + resource.getTarget() + " since immutable_paths contains it.");
                    continue;
                }

                if (resource.getAction().equals("create")) {
                    // 5 - Create
                    Resource.createResource(resource, dfs, pathHadoop);
                    Resource.setMode(resource, dfs, pathHadoop);
                    Resource.setOwner(resource, dfs, pathHadoop);
                } else if (resource.getAction().equals("delete")) {
                    // 6 - Delete
                    dfs.delete(pathHadoop, true);
                }
            }
        } catch (Exception e) {
            System.out.println("Exception occurred, Reason: " + e.getMessage());
            e.printStackTrace();
        } finally {
            dfs.close();
        }

        System.out.println("All resources created.");
    }

}