getversiontask.java

一个java写的business process management系统

/*
 * Copyright (c) 2003, Alexander Greif
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the Flow4J-Eclipse project nor the names of its
 *       contributors may be used to endorse or promote products derived from
 *       this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

package net.orthanc.flow4j.flows.updateflowfile;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParserFactory;

import net.orthanc.flow4j.runtime.AbstractTaskFlowlet;
import net.orthanc.flow4j.runtime.Flow4JRuntimeException;
import net.orthanc.flow4j.runtime.FlowDictionary;
import net.orthanc.flow4j.runtime.FlowManager;
import net.orthanc.flow4j.runtime.descriptors.TaskPropertyDescriptors;

import org.xml.sax.Attributes;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;

/**
 * @author agreif
 *
 * This tasl puts the flow file's version in the dictionary.
 */
public class GetVersionTask extends AbstractTaskFlowlet {


//	private static final String DEFAULT_PARSER_NAME = "org.apache.xerces.parsers.SAXParser";


	/**
	 * @see net.orthanc.flow4j.runtime.ITaskFlowlet#getTaskName()
	 */
	public String getName() {
		return "GetVersion";
	}


	/**
	 * @see net.orthanc.flow4j.runtime.ITaskFlowlet#getDescription()
	 */
	public String getDescription() {
		return "Puts the flow file's version in the dictionary";
	}


	/* 
	 * TODO
	 * @see net.orthanc.flow4j.runtime.ITaskFlowlet#getPropertyDescriptors()
	 */
	public TaskPropertyDescriptors getPropertyDescriptors() {
		return null;
	}


	/**
	 * Puts the flow file's version in the dictionary
	 * @see net.orthanc.flow4j.runtime.IFlowlet#execute(net.orthanc.flow4j.runtime.FlowDictionary)
	 */
	public void execute(FlowDictionary dictionary) {
		File flowFile = (File)dictionary.get(UpdateFlowFileConsts.KEY_FLOW_FILE);
		if (flowFile == null)
			throw new Flow4JRuntimeException("Flow file not specified");
		if (!flowFile.exists())
			throw new Flow4JRuntimeException("specified flow file \"" + flowFile + "\" does not exist");

		/*try {
			parser = XMLReaderFactory.createXMLReader(DEFAULT_PARSER_NAME);
		} catch (SAXException e) {
			throw new Flow4JRuntimeException("Unable to instantiate parser (" + DEFAULT_PARSER_NAME + ")", e);
		}*/

		SAXHandler handler = new SAXHandler();
		Reader flowFileReader = null;
		try {
			XMLReader parser = SAXParserFactory.newInstance().newSAXParser().getXMLReader();
			parser.setContentHandler(handler);
			flowFileReader = new BufferedReader(new FileReader(flowFile));
			InputSource source = new InputSource(flowFileReader);
			parser.parse(source);
			dictionary.put(UpdateFlowFileConsts.KEY_VERSION, new Integer(handler.getVersion()));
		} catch (FileNotFoundException e1) {
			// already checked
		} catch (IOException e1) {
			throw new Flow4JRuntimeException(e1);
		} catch (SAXException e1) {
			throw new Flow4JRuntimeException(e1);
		} catch (ParserConfigurationException e1) {
			throw new Flow4JRuntimeException(e1);
		} finally {
			if (flowFileReader != null)
				try {
					flowFileReader.close();
				} catch (Exception e) {
				}
		}
	}

	/**
	 * @author agreif
	 *
	 * TODO
	 * 
	 * To change the template for this generated type comment go to
	 * Window>Preferences>Java>Code Generation>Code and Comments
	 */
	private class SAXHandler extends DefaultHandler {

		private boolean foundVersion = false;
		private String version;

		/**
		 * TODO
		 * @return
		 */
		public int getVersion() {
			return Integer.parseInt(version);
		}

		/**
		 * @see org.xml.sax.ContentHandler#startElement(java.lang.String, java.lang.String, java.lang.String, org.xml.sax.Attributes)
		 */
		public void startElement(String uri, String localName, String qName, Attributes attributes)
			throws SAXException {
			if (foundVersion)
				return;

			String version = attributes.getValue("version");
			if (version == null)
				return;

			this.version = version;
			foundVersion = true;
		}

	}

	/**
	 * For testing purposes
	 * @param args
	 */
	public static void main(String[] args) {
		FlowManager.registerFlow(UpdateFlowFileFlow.class);
		FlowDictionary dictionary = new FlowDictionary();
		dictionary.put(UpdateFlowFileConsts.KEY_FLOW_FILE, new File("/Volumes/data/tmp/UpdateFlowFile.f4j"));
		FlowManager.executeFlow("UpdateFlowFile", "Start", dictionary);
		System.out.println(dictionary);
	}

}