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.ByteArrayInputStream; 021 import java.io.IOException; 022 import java.io.InputStream; 023 024 import org.xml.sax.SAXException; 025 import org.apache.oozie.action.hadoop.FileSystemActions; 026 import org.w3c.dom.Document; 027 import org.w3c.dom.NodeList; 028 import javax.xml.parsers.DocumentBuilderFactory; 029 import javax.xml.parsers.DocumentBuilder; 030 import javax.xml.parsers.ParserConfigurationException; 031 032 /** 033 * Utility class to perform operations on the prepare block of Workflow 034 * 035 */ 036 public class PrepareActionsDriver { 037 038 /** 039 * Method to parse the prepare XML and execute the corresponding prepare actions 040 * 041 * @param prepareXML Prepare XML block in string format 042 * @throws LauncherException 043 */ 044 static void doOperations(String prepareXML) throws LauncherException { 045 try { 046 Document doc = getDocumentFromXML(prepareXML); 047 doc.getDocumentElement().normalize(); 048 049 // Get the list of child nodes, basically, each one corresponding to a separate action 050 NodeList nl = doc.getDocumentElement().getChildNodes(); 051 FileSystemActions fsActions = new FileSystemActions(); 052 053 for (int i = 0; i < nl.getLength(); ++i) { 054 String commandType = ""; 055 /* Logic to find the command type goes here 056 commandType = ..........; 057 */ 058 // As of now, the available prepare action is of type hdfs. Hence, assigning the value directly 059 commandType = "hdfs"; 060 if (commandType.equalsIgnoreCase("hdfs")) { 061 fsActions.execute(nl.item(i)); 062 } /*else if(commandType.equalsIgnoreCase("hcat")) { //Other command types go here 063 hCatActions.execute(nl.item(i)); 064 }*/ 065 } 066 } catch (IOException ioe) { 067 throw new LauncherException(ioe.getMessage(), ioe); 068 } catch (SAXException saxe) { 069 throw new LauncherException(saxe.getMessage(), saxe); 070 } catch (ParserConfigurationException pce) { 071 throw new LauncherException(pce.getMessage(), pce); 072 } 073 } 074 075 // Method to return the document from the prepare XML block 076 static Document getDocumentFromXML(String prepareXML) throws ParserConfigurationException, SAXException, 077 IOException { 078 DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance(); 079 DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder(); 080 InputStream is = new ByteArrayInputStream(prepareXML.getBytes("UTF-8")); 081 return docBuilder.parse(is); 082 } 083 }