org.openbpmn.bpmn.util.BPMNModelFactory Maven / Gradle / Ivy
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package org.openbpmn.bpmn.util;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Logger;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.openbpmn.bpmn.BPMNModel;
import org.openbpmn.bpmn.exceptions.BPMNInvalidIDException;
import org.openbpmn.bpmn.exceptions.BPMNModelException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.SAXException;
/**
* The BPMNModelFactory can be used to load or create a BPMNModel instance.
*
* @author rsoika
*
*/
public class BPMNModelFactory {
private static Logger logger = Logger.getLogger(BPMNModelFactory.class.getName());
public static final String DEFAULT_EXPORTER = "org.openbpmn";
public static final String DEFAULT_VERSION = "1.0.0";
public static final String DEFAULT_TARGETNAMESPACE = "http://open-bpmn.org";
public static final String OPEN_BPMN_NAMESPACE = "open-bpmn";
public static final String OPEN_BPMN_SCHEMA = "http://open-bpmn.org/XMLSchema";
/**
* This method creates a new empty BPMNModel instance. The BPMNModel is
* initialized with the BPMN default namespaces.
*
* @param exporter
* @param exporterVersion
* @param targetNamespace
* @return
*/
public static BPMNModel createInstance(String exporter, String exporterVersion, String targetNamespace) {
DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
docFactory.setNamespaceAware(true);
DocumentBuilder docBuilder;
try {
docBuilder = docFactory.newDocumentBuilder();
/*
*
*/
// root elements
Document doc = docBuilder.newDocument();
Element definitions = doc.createElementNS("http://www.omg.org/spec/BPMN/20100524/MODEL",
"bpmn2:definitions");
// set BPMN default namespaces
definitions.setAttribute("xmlns:bpmndi", "http://www.omg.org/spec/BPMN/20100524/DI");
definitions.setAttribute("xmlns:di", "http://www.omg.org/spec/DD/20100524/DI");
definitions.setAttribute("xmlns:dc", "http://www.omg.org/spec/DD/20100524/DC");
definitions.setAttribute("xmlns:xs", "http://www.w3.org/2001/XMLSchema");
definitions.setAttribute("xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance");
setOpenBPMNNameSpace(definitions);
// set definitions attributes
definitions.setAttribute("exporter", exporter);
definitions.setAttribute("exporterVersion", exporterVersion);
definitions.setAttribute("targetNamespace", targetNamespace);
doc.appendChild(definitions);
BPMNModel model = new BPMNModel(doc);
return model;
} catch (ParserConfigurationException | BPMNModelException e1) {
e1.printStackTrace();
}
return null;
}
/**
* Reads a BPMNModel instance from an java.io.File
*
* @param modelFile
* @return a BPMNModel instance
* @throws BPMNModelException
* @throws FileNotFoundException
* @throws IOException
*/
public static BPMNModel read(File modelFile) throws BPMNModelException {
try {
return read(new FileInputStream(modelFile));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return null;
}
/**
* Reads a BPMNModel instance from an given file path
*
* @param modelFile
* @return a BPMNModel instance
* @throws BPMNModelException
* @throws IOException
*/
public static BPMNModel read(String modelFilePath) throws BPMNModelException {
return read(BPMNModel.class.getResourceAsStream(modelFilePath));
}
/**
* Reads a BPMNModel instance from an InputStream.
*
* The method cleans whitespace after reading the file for a better handling and
* later output format.
*
* If the file is empty, the mmethod creates automatically a default process. In
* addition the Open-BPMN extension 'allign-to-grid' is set to true. This option
* can be deactivated in the model properties.
*
* @param modelFile
* @return a BPMNModel instance
* @throws BPMNModelException
* @throws FileNotFoundException
* @throws IOException
*/
public static BPMNModel read(InputStream is) throws BPMNModelException {
logger.fine("read from inputStream...");
if (is == null) {
throw new BPMNInvalidIDException(BPMNModelException.INVALID_MODEL,
"Model can not be parsed: InputStream is null");
}
DocumentBuilderFactory docFactory = DocumentBuilderFactory
.newInstance();
docFactory.setIgnoringElementContentWhitespace(true); // because of a bug this does not have
// any effect!
docFactory.setNamespaceAware(true);
try {
if (is.available() == 0) {
logger.warning("Empty BPMN file - creating a default process");
// create a default model
BPMNModel defaultModel = BPMNModelFactory
.createInstance(DEFAULT_EXPORTER, DEFAULT_VERSION, DEFAULT_TARGETNAMESPACE);
return defaultModel;
}
// parse XML file
DocumentBuilder db = docFactory.newDocumentBuilder();
// read from a project's resources folder
Document doc = db.parse(is);
Element root = doc.getDocumentElement();
// explicit remove whitespace
removeWhitespaceNodes(root);
BPMNModel model = new BPMNModel(doc);
setOpenBPMNNameSpace(model.getDefinitions());
return model;
} catch (ParserConfigurationException | SAXException | IOException e) {
logger.severe(e.getMessage());
// create a runtimeException to show a error message in the client
throw new RuntimeException(e);
} finally {
if (is != null) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
/**
* Helper Method to add the open-bpmn namespace to the definitions element
*
* @param definitions
*/
private static void setOpenBPMNNameSpace(Element definitions) {
if (!definitions.hasAttribute("xmlns:" + OPEN_BPMN_NAMESPACE)) {
definitions.setAttribute("xmlns:" + OPEN_BPMN_NAMESPACE, OPEN_BPMN_SCHEMA);
}
}
/**
* Removes whitespace from an Element
*
* This helper method is needed as the Dom XML parser does not remove
* whitespaces despite the hint enabled.
*
* @see https://coderbyheart.com/jaxp-dom-whitespace-aus-xml-entfernen
* @see http://forums.java.net/jive/thread.jspa?messageID=345459
* @param e
*/
private static void removeWhitespaceNodes(Element e) {
NodeList children = e.getChildNodes();
for (int i = children.getLength() - 1; i >= 0; i--) {
Node child = children.item(i);
if (child instanceof Text && ((Text) child).getData().trim().length() == 0) {
e.removeChild(child);
} else if (child instanceof Element) {
removeWhitespaceNodes((Element) child);
}
}
}
}