001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 package org.apache.oozie.action.hadoop;
019
020 import java.io.IOException;
021 import java.util.HashSet;
022 import java.util.Set;
023
024 import org.apache.hadoop.fs.FileSystem;
025 import org.apache.hadoop.conf.Configuration;
026 import org.apache.hadoop.fs.Path;
027 import org.w3c.dom.Node;
028 /**
029 * Class to perform file system operations specified in the prepare block of Workflow
030 *
031 */
032 public class FileSystemActions {
033 private static Set<String> supportedFileSystems = new HashSet<String>();
034
035 public FileSystemActions() {
036 supportedFileSystems.add("hdfs");
037 }
038
039 public FileSystemActions(Set<String> fileSystems) {
040 supportedFileSystems = fileSystems;
041 }
042
043 /**
044 * Method to execute the prepare actions based on the command
045 *
046 * @param n Child node of the prepare XML
047 * @throws LauncherException
048 */
049 public void execute(Node n) throws LauncherException {
050 String command = n.getNodeName();
051 if (command.equals("delete")) {
052 delete(new Path(n.getAttributes().getNamedItem("path").getNodeValue().trim()));
053 } else if (command.equals("mkdir")) {
054 mkdir(new Path(n.getAttributes().getNamedItem("path").getNodeValue().trim()));
055 }
056 }
057
058 // Method to delete the specified file based on the path
059 private void delete(Path path) throws LauncherException {
060 try {
061 validatePath(path, true);
062 FileSystem fs = FileSystem.get(path.toUri(), new Configuration());
063 if (fs.exists(path)) {
064 if (!fs.delete(path, true)) {
065 String deleteFailed = "Deletion of path " + path.toString() + " failed.";
066 System.out.println(deleteFailed);
067 throw new LauncherException(deleteFailed);
068 } else {
069 System.out.println("Deletion of path " + path.toString() + " was successful.");
070 }
071 }
072 } catch (IOException ex) {
073 throw new LauncherException(ex.getMessage(), ex);
074 }
075
076 }
077
078 // Method to create a directory based on the path
079 private void mkdir(Path path) throws LauncherException {
080 try {
081 validatePath(path, true);
082 FileSystem fs = FileSystem.get(path.toUri(), new Configuration());
083 if (!fs.exists(path)) {
084 if (!fs.mkdirs(path)) {
085 String mkdirFailed = "Creating directory at " + path + " failed.";
086 System.out.println(mkdirFailed);
087 throw new LauncherException(mkdirFailed);
088 } else {
089 System.out.println("Creating directory at path " + path + " was successful.");
090 }
091 }
092 } catch (IOException ex) {
093 throw new LauncherException(ex.getMessage(), ex);
094 }
095 }
096
097 // Method to validate the path provided for the prepare action
098 private void validatePath(Path path, boolean withScheme) throws LauncherException {
099 String scheme = path.toUri().getScheme();
100 if (withScheme) {
101 if (scheme == null) {
102 String nullScheme = "Scheme of the path " + path + " is null";
103 System.out.println(nullScheme);
104 throw new LauncherException(nullScheme);
105 } else if (!supportedFileSystems.contains(scheme.toLowerCase())) {
106 String unsupportedScheme = "Scheme of the provided path " + path + " is of type not supported.";
107 System.out.println(unsupportedScheme);
108 throw new LauncherException(unsupportedScheme);
109 }
110 } else if (scheme != null) {
111 String notNullScheme = "Scheme of the path " + path + " is not null as specified.";
112 System.out.println(notNullScheme);
113 throw new LauncherException(notNullScheme);
114 }
115 }
116 }