activiti-bpmn-converter

目录
- 概述
- - 需求：
- 设计思路
- 实现思路分析
- - 1.BpmnXMLConstants
  - 2.BpmnXMLConverter
  - 3.StartEventXMLConverter
  - 4.EndEventXMLConverter
参考资料和推荐阅读

Survive by day and develop by night.
talk for import biz , show your perfect code,full busy，skip hardness,make a better result,wait for change,challenge Survive.
happy for hardess to solve denpendies.

public interface BpmnXMLConstants {

  public static final String BPMN2_NAMESPACE = "http://www.omg.org/spec/BPMN/20100524/MODEL";
  public static final String BPMN2_PREFIX = "bpmn2";
  public static final String XSI_NAMESPACE = "http://www.w3.org/2001/XMLSchema-instance";
  public static final String XSI_PREFIX = "xsi";
  public static final String SCHEMA_NAMESPACE = "http://www.w3.org/2001/XMLSchema";
  public static final String XSD_PREFIX = "xsd";
  public static final String TYPE_LANGUAGE_ATTRIBUTE = "typeLanguage";
  public static final String XPATH_NAMESPACE = "http://www.w3.org/1999/XPath";
  public static final String EXPRESSION_LANGUAGE_ATTRIBUTE = "expressionLanguage";
  public static final String PROCESS_NAMESPACE = "http://www.activiti.org/test";
  public static final String TARGET_NAMESPACE_ATTRIBUTE = "targetNamespace";
  public static final String ACTIVITI_EXTENSIONS_NAMESPACE = "http://activiti.org/bpmn";
  public static final String ACTIVITI_EXTENSIONS_PREFIX = "activiti";
  public static final String BPMNDI_NAMESPACE = "http://www.omg.org/spec/BPMN/20100524/DI";
  public static final String BPMNDI_PREFIX = "bpmndi";
  public static final String OMGDC_NAMESPACE = "http://www.omg.org/spec/DD/20100524/DC";
  public static final String OMGDC_PREFIX = "omgdc";
  public static final String OMGDI_NAMESPACE = "http://www.omg.org/spec/DD/20100524/DI";
  public static final String OMGDI_PREFIX = "omgdi";

2.BpmnXMLConverter

public class BpmnXMLConverter implements BpmnXMLConstants {

  protected static final Logger LOGGER = LoggerFactory.getLogger(BpmnXMLConverter.class);

  protected static final String BPMN_XSD = "org/activiti/impl/bpmn/parser/BPMN20.xsd";
  protected static final String DEFAULT_ENCODING = "UTF-8";

  protected static Map<String, BaseBpmnXMLConverter> convertersToBpmnMap = new HashMap<String, BaseBpmnXMLConverter>();
  protected static Map<Class<? extends BaseElement>, BaseBpmnXMLConverter> convertersToXMLMap = new HashMap<Class<? extends BaseElement>, BaseBpmnXMLConverter>();

  protected ClassLoader classloader;
  protected List<String> userTaskFormTypes;
  protected List<String> startEventFormTypes;

  protected BpmnEdgeParser bpmnEdgeParser = new BpmnEdgeParser();
  protected BpmnShapeParser bpmnShapeParser = new BpmnShapeParser();
  protected DefinitionsParser definitionsParser = new DefinitionsParser();
  protected DocumentationParser documentationParser = new DocumentationParser();
  protected ExtensionElementsParser extensionElementsParser = new ExtensionElementsParser();
  protected ImportParser importParser = new ImportParser();
  protected InterfaceParser interfaceParser = new InterfaceParser();
  protected ItemDefinitionParser itemDefinitionParser = new ItemDefinitionParser();
  protected IOSpecificationParser ioSpecificationParser = new IOSpecificationParser();
  protected DataStoreParser dataStoreParser = new DataStoreParser();
  protected LaneParser laneParser = new LaneParser();
  protected MessageParser messageParser = new MessageParser();
  protected MessageFlowParser messageFlowParser = new MessageFlowParser();
  protected MultiInstanceParser multiInstanceParser = new MultiInstanceParser();
  protected ParticipantParser participantParser = new ParticipantParser();
  protected PotentialStarterParser potentialStarterParser = new PotentialStarterParser();
  protected ProcessParser processParser = new ProcessParser();
  protected ResourceParser resourceParser = new ResourceParser();
  protected SignalParser signalParser = new SignalParser();
  protected SubProcessParser subProcessParser = new SubProcessParser();

  static {
    // events
    addConverter(new EndEventXMLConverter());
    addConverter(new StartEventXMLConverter());

    // tasks
    addConverter(new BusinessRuleTaskXMLConverter());
    addConverter(new ManualTaskXMLConverter());
    addConverter(new ReceiveTaskXMLConverter());
    addConverter(new ScriptTaskXMLConverter());
    addConverter(new ServiceTaskXMLConverter());
    addConverter(new SendTaskXMLConverter());
    addConverter(new UserTaskXMLConverter());
    addConverter(new TaskXMLConverter());
    addConverter(new CallActivityXMLConverter());

    // gateways
    addConverter(new EventGatewayXMLConverter());
    addConverter(new ExclusiveGatewayXMLConverter());
    addConverter(new InclusiveGatewayXMLConverter());
    addConverter(new ParallelGatewayXMLConverter());
    addConverter(new ComplexGatewayXMLConverter());

    // connectors
    addConverter(new SequenceFlowXMLConverter());

    // catch, throw and boundary event
    addConverter(new CatchEventXMLConverter());
    addConverter(new ThrowEventXMLConverter());
    addConverter(new BoundaryEventXMLConverter());

    // artifacts
    addConverter(new TextAnnotationXMLConverter());
    addConverter(new AssociationXMLConverter());

    // data store reference
    addConverter(new DataStoreReferenceXMLConverter());

    // data objects
    addConverter(new ValuedDataObjectXMLConverter(), StringDataObject.class);
    addConverter(new ValuedDataObjectXMLConverter(), BooleanDataObject.class);
    addConverter(new ValuedDataObjectXMLConverter(), IntegerDataObject.class);
    addConverter(new ValuedDataObjectXMLConverter(), LongDataObject.class);
    addConverter(new ValuedDataObjectXMLConverter(), DoubleDataObject.class);
    addConverter(new ValuedDataObjectXMLConverter(), DateDataObject.class);

    // Alfresco types
    addConverter(new AlfrescoStartEventXMLConverter());
    addConverter(new AlfrescoUserTaskXMLConverter());
  }

  public static void addConverter(BaseBpmnXMLConverter converter) {
    addConverter(converter, converter.getBpmnElementType());
  }

  public static void addConverter(BaseBpmnXMLConverter converter, Class<? extends BaseElement> elementType) {
    convertersToBpmnMap.put(converter.getXMLElementName(), converter);
    convertersToXMLMap.put(elementType, converter);
  }

在这里插入图片描述
convertToBpmnModel流程如下

3.StartEventXMLConverter

public class StartEventXMLConverter extends BaseBpmnXMLConverter {

    @Override
    public Class<? extends BaseElement> getBpmnElementType() {
        return StartEvent.class;
    }

    @Override
    protected String getXMLElementName() {
        return ELEMENT_EVENT_START;
    }

    @Override
    protected BaseElement convertXMLToElement(XMLStreamReader xtr,
                                              BpmnModel model) throws Exception {
        String formKey = xtr.getAttributeValue(ACTIVITI_EXTENSIONS_NAMESPACE,
                                               ATTRIBUTE_FORM_FORMKEY);
        StartEvent startEvent = null;

        if (StringUtils.isNotEmpty(formKey) && model.getStartEventFormTypes() != null && model.getStartEventFormTypes().contains(formKey)) {
            startEvent = new AlfrescoStartEvent();
        }
        if (startEvent == null) {
            startEvent = new StartEvent();
        }
        BpmnXMLUtil.addXMLLocation(startEvent,
                                   xtr);
        startEvent.setInitiator(xtr.getAttributeValue(ACTIVITI_EXTENSIONS_NAMESPACE,
                                                      ATTRIBUTE_EVENT_START_INITIATOR));
        boolean interrupting = true;
        String interruptingAttribute = xtr.getAttributeValue(null,
                                                             ATTRIBUTE_EVENT_START_INTERRUPTING);
        if (ATTRIBUTE_VALUE_FALSE.equalsIgnoreCase(interruptingAttribute)) {
            interrupting = false;
        }
        startEvent.setInterrupting(interrupting);
        startEvent.setFormKey(formKey);

        parseChildElements(getXMLElementName(),
                           startEvent,
                           model,
                           xtr);

        return startEvent;
    }

    @Override
    protected void writeAdditionalAttributes(BaseElement element,
                                             BpmnModel model,
                                             XMLStreamWriter xtw) throws Exception {
        StartEvent startEvent = (StartEvent) element;
        writeQualifiedAttribute(ATTRIBUTE_EVENT_START_INITIATOR,
                                startEvent.getInitiator(),
                                xtw);
        writeQualifiedAttribute(ATTRIBUTE_FORM_FORMKEY,
                                startEvent.getFormKey(),
                                xtw);

        if (startEvent.getEventDefinitions() != null && startEvent.getEventDefinitions().size() > 0) {
            writeDefaultAttribute(ATTRIBUTE_EVENT_START_INTERRUPTING,
                                    String.valueOf(startEvent.isInterrupting()),
                                    xtw);
        }
    }

    @Override
    protected boolean writeExtensionChildElements(BaseElement element,
                                                  boolean didWriteExtensionStartElement,
                                                  XMLStreamWriter xtw) throws Exception {
        StartEvent startEvent = (StartEvent) element;
        didWriteExtensionStartElement = writeFormProperties(startEvent,
                                                            didWriteExtensionStartElement,
                                                            xtw);
        return didWriteExtensionStartElement;
    }

    @Override
    protected void writeAdditionalChildElements(BaseElement element,
                                                BpmnModel model,
                                                XMLStreamWriter xtw) throws Exception {
        StartEvent startEvent = (StartEvent) element;
        writeEventDefinitions(startEvent,
                              startEvent.getEventDefinitions(),
                              model,
                              xtw);
    }

}

在这里插入图片描述

convertXMLToElement项目流程如下：

4.EndEventXMLConverter

public class EndEventXMLConverter extends BaseBpmnXMLConverter {

  @Override
  public Class<? extends BaseElement> getBpmnElementType() {
    return EndEvent.class;
  }

  @Override
  protected String getXMLElementName() {
    return ELEMENT_EVENT_END;
  }

  @Override
  protected BaseElement convertXMLToElement(XMLStreamReader xtr, BpmnModel model) throws Exception {
    EndEvent endEvent = new EndEvent();
    BpmnXMLUtil.addXMLLocation(endEvent, xtr);
    parseChildElements(getXMLElementName(), endEvent, model, xtr);
    return endEvent;
  }

  @Override
  protected void writeAdditionalAttributes(BaseElement element, BpmnModel model, XMLStreamWriter xtw) throws Exception {
  }

  @Override
  protected void writeAdditionalChildElements(BaseElement element, BpmnModel model, XMLStreamWriter xtw) throws Exception {
    EndEvent endEvent = (EndEvent) element;
    writeEventDefinitions(endEvent, endEvent.getEventDefinitions(), model, xtw);
  }