org.apache.oozie.action.hadoop.PrepareActionsHandler Maven / Gradle / Ivy
/**
* 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.oozie.action.hadoop;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
public class PrepareActionsHandler {
/**
* Method to parse the prepare XML and execute the corresponding prepare actions
*
* @param prepareXML Prepare XML block in string format
* @param conf the configuration
* @throws IOException if there is an IO error during prepare action
* @throws SAXException in case of xml parsing error
* @throws ParserConfigurationException if the parser is not well configured
* @throws LauncherException in case of error
*/
public void prepareAction(String prepareXML, Configuration conf)
throws IOException, SAXException, ParserConfigurationException, LauncherException {
Document doc = getDocumentFromXML(prepareXML);
doc.getDocumentElement().normalize();
// Get the list of child nodes, basically, each one corresponding to a separate action
NodeList nl = doc.getDocumentElement().getChildNodes();
LauncherURIHandlerFactory factory = new LauncherURIHandlerFactory(conf);
for (int i = 0; i < nl.getLength(); ++i) {
Node n = nl.item(i);
String operation = n.getNodeName();
if (n.getAttributes() == null || n.getAttributes().getNamedItem("path") == null) {
continue;
}
String pathStr = n.getAttributes().getNamedItem("path").getNodeValue().trim();
// use Path to avoid URIsyntax error caused by square bracket in glob
URI uri = new Path(pathStr).toUri();
LauncherURIHandler handler = factory.getURIHandler(uri);
execute(operation, uri, handler, conf);
}
}
private void execute(String operation, URI uri, LauncherURIHandler handler, Configuration conf)
throws LauncherException {
switch (operation) {
case "delete":
handler.delete(uri, conf);
break;
case "mkdir":
handler.create(uri, conf);
break;
default:
System.out.println("Warning: unknown prepare operation " + operation + " -- skipping");
}
}
// Method to return the document from the prepare XML block
static Document getDocumentFromXML(String prepareXML) throws ParserConfigurationException, SAXException,
IOException {
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
docBuilderFactory.setNamespaceAware(true);
// support for includes in the xml file
docBuilderFactory.setXIncludeAware(true);
// ignore all comments inside the xml file
docBuilderFactory.setIgnoringComments(true);
docBuilderFactory.setExpandEntityReferences(false);
docBuilderFactory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
InputStream is = new ByteArrayInputStream(prepareXML.getBytes("UTF-8"));
return docBuilder.parse(is);
}
}