activiti自定义BPMN标签报：org.xml.sax.SAXParseException: 已经为元素 userTask 指定绑定到名称空间 http://activiti.org/bpmn

刺骨的言语ヽ痛彻心扉 2023-02-12 14:25 32阅读 0赞

项目地址：[activiti-workflow][]

**在给用户节点扩展增加抄送人的标签，通过bpmn文件导入流程报org.xml.sax.SAXParseException: 已经为元素 “userTask” 指定绑定到名称空间 “http://activiti.org/bpmn” 的属性 "XXXX。"**

通过bebuggerf发现具体报错出现在**XMLNSDocumentScannerImpl**类

if (length > 1) { 
     		//对元素进行校验name不为空说明有重复元素
    	   QName name = fAttributes.checkDuplicatesNS();
           if (name != null) { 
               if (name.uri != null) { 
                   fErrorReporter.reportError(XMLMessageFormatter.XMLNS_DOMAIN,
                           "AttributeNSNotUnique",
                           new Object[]{ fElementQName.rawname, name.localpart, name.uri},
                           XMLErrorReporter.SEVERITY_FATAL_ERROR);
               } else { 
                   fErrorReporter.reportError(XMLMessageFormatter.XMLNS_DOMAIN,
                           "AttributeNotUnique",
                           new Object[]{ fElementQName.rawname, name.rawname},
                           XMLErrorReporter.SEVERITY_FATAL_ERROR);
               }
           }
       }

在看checkDuplicatesNS方法

public QName checkDuplicatesNS() { 
            // If the list is small check for duplicates using pairwise comparison.
            final int length = fLength;
            if (length <= SIZE_LIMIT) { 
                final Attribute[] attributes = fAttributes;
                for (int i = 0; i < length - 1; ++i) { 
                    Attribute att1 = attributes[i];
                    for (int j = i + 1; j < length; ++j) { 
                        Attribute att2 = attributes[j];
                        //只有当标签名称和命名空间一样时有返回
                        if (att1.name.localpart == att2.name.localpart &&
                            att1.name.uri == att2.name.uri) { 
                            return att2.name;
                        }
                    }
                }
                return null;
            }
            // If the list is large check duplicates using a hash table.
            else { 
                return checkManyDuplicatesNS();
            }
        }

贴上报错的对象信息  
![在这里插入图片描述][20200526145458201.png]  
按理说不会存在两个一样的标签，莫非时重复设置，仔细检查代码后，并没有发现重复设置的地方。  
自己扩展的代码，只有在**CustomUserTaskXMLConverter**一处设置的这个属性

@Override
      @SuppressWarnings("unchecked")
      protected void writeAdditionalAttributes(BaseElement element, BpmnModel model, XMLStreamWriter xtw) throws Exception { 
    	//省略部分代码
        //设置抄送标签属性
        writeQualifiedAttribute(ATTRIBUTE_TASK_USER_CANDIDATE_NOTIFY_USERS, convertToDelimitedString(userTask.getCandidateNotifyUsers()), xtw);
       	//省略部分代码
        // 注意，注意，注意
        BpmnXMLUtil.writeCustomAttributes(userTask.getAttributes().values(), xtw, defaultElementAttributes,
            defaultActivityAttributes, defaultUserTaskAttributes);
      }

到这里可以断定是activiti的源码设置了另外一个属性。activiti解析bpmn文件是从BaseBpmnXMLConverter\#convertToXML开始，

public void convertToXML(XMLStreamWriter xtw, BaseElement baseElement, BpmnModel model) throws Exception { 
        xtw.writeStartElement(getXMLElementName());
        boolean didWriteExtensionStartElement = false;
        writeDefaultAttribute(ATTRIBUTE_ID, baseElement.getId(), xtw);
        if (baseElement instanceof FlowElement) { 
          writeDefaultAttribute(ATTRIBUTE_NAME, ((FlowElement) baseElement).getName(), xtw);
        }
        
        if (baseElement instanceof FlowNode) { 
          final FlowNode flowNode = (FlowNode) baseElement;
          if (flowNode.isAsynchronous()) { 
            writeQualifiedAttribute(ATTRIBUTE_ACTIVITY_ASYNCHRONOUS, ATTRIBUTE_VALUE_TRUE, xtw);
            if (flowNode.isNotExclusive()) { 
              writeQualifiedAttribute(ATTRIBUTE_ACTIVITY_EXCLUSIVE, ATTRIBUTE_VALUE_FALSE, xtw);
            }
          }
          
          if (baseElement instanceof Activity) { 
            final Activity activity = (Activity) baseElement;
            if (activity.isForCompensation()) { 
              writeDefaultAttribute(ATTRIBUTE_ACTIVITY_ISFORCOMPENSATION, ATTRIBUTE_VALUE_TRUE, xtw);
            }
            if (StringUtils.isNotEmpty(activity.getDefaultFlow())) { 
              FlowElement defaultFlowElement = model.getFlowElement(activity.getDefaultFlow());
              if (defaultFlowElement instanceof SequenceFlow) { 
                writeDefaultAttribute(ATTRIBUTE_DEFAULT, activity.getDefaultFlow(), xtw);
              }
            }
          }
          
          if (baseElement instanceof Gateway) { 
            final Gateway gateway = (Gateway) baseElement;
            if (StringUtils.isNotEmpty(gateway.getDefaultFlow())) { 
              FlowElement defaultFlowElement = model.getFlowElement(gateway.getDefaultFlow());
              if (defaultFlowElement instanceof SequenceFlow) { 
                writeDefaultAttribute(ATTRIBUTE_DEFAULT, gateway.getDefaultFlow(), xtw);
              }
            }
          }
        }
    	//具体子类执行
        writeAdditionalAttributes(baseElement, model, xtw);
    
        if (baseElement instanceof FlowElement) { 
          final FlowElement flowElement = (FlowElement) baseElement;
          if (StringUtils.isNotEmpty(flowElement.getDocumentation())) { 
    
            xtw.writeStartElement(ELEMENT_DOCUMENTATION);
            xtw.writeCharacters(flowElement.getDocumentation());
            xtw.writeEndElement();
          }
        }
    
        didWriteExtensionStartElement = writeExtensionChildElements(baseElement, didWriteExtensionStartElement, xtw);
        didWriteExtensionStartElement = writeListeners(baseElement, didWriteExtensionStartElement, xtw);
        didWriteExtensionStartElement = BpmnXMLUtil.writeExtensionElements(baseElement, didWriteExtensionStartElement, model.getNamespaces(), xtw);
        if (baseElement instanceof Activity) { 
          final Activity activity = (Activity) baseElement;
          FailedJobRetryCountExport.writeFailedJobRetryCount(activity, xtw);
    
        }
    
        if (didWriteExtensionStartElement) { 
          xtw.writeEndElement();
        }
    
        if (baseElement instanceof Activity) { 
          final Activity activity = (Activity) baseElement;
          MultiInstanceExport.writeMultiInstance(activity, xtw);
    
        }
    
        writeAdditionalChildElements(baseElement, model, xtw);
    
        xtw.writeEndElement();
      }

在这个方法内没有发现设置的代码，只能看子类。注意看上面CustomUserTaskXMLConverter的writeAdditionalAttributes方法

BpmnXMLUtil.writeCustomAttributes(userTask.getAttributes().values(), xtw, defaultElementAttributes,
            defaultActivityAttributes, defaultUserTaskAttributes);

这里并没有设置userTask的attributes属性，应该是空的，单跟进去发现并不是，刚好是抄送的属性。到这里就明白了，另外一次的设置就在这里。  
![在这里插入图片描述][2020052615093151.png]

到这里就只需要确定attributes是在什么时候设置的。在**BaseElement\#addAttribute**设置断点。最后发现实在**CustomUserTaskXMLConverter\#convertXMLToElement**方法

@Override
      protected BaseElement convertXMLToElement(XMLStreamReader xtr, BpmnModel model) throws Exception { 
       	//省略部分代码
       	//设置Attributes属性
        BpmnXMLUtil.addCustomAttributes(xtr, userTask, defaultElementAttributes,
            defaultActivityAttributes, defaultUserTaskAttributes);
    
        parseChildElements(getXMLElementName(), userTask, childParserMap, model, xtr);
        
        return userTask;
      }

**BpmnXMLUtil.addCustomAttributes**方法，主要在**isBlacklisted**

public static void addCustomAttributes(XMLStreamReader xtr, BaseElement element, List<ExtensionAttribute>... blackLists) { 
    	//迭代出各个属性判断是否有命名空间，是否是自定义属性
        for (int i = 0; i < xtr.getAttributeCount(); i++) { 
          ExtensionAttribute extensionAttribute = new ExtensionAttribute();
          extensionAttribute.setName(xtr.getAttributeLocalName(i));
          extensionAttribute.setValue(xtr.getAttributeValue(i));
          if (StringUtils.isNotEmpty(xtr.getAttributeNamespace(i))) { 
            extensionAttribute.setNamespace(xtr.getAttributeNamespace(i));
          }
          if (StringUtils.isNotEmpty(xtr.getAttributePrefix(i))) { 
            extensionAttribute.setNamespacePrefix(xtr.getAttributePrefix(i));
          }
          if (!isBlacklisted(extensionAttribute, blackLists)) { 
            element.addAttribute(extensionAttribute);
          }
        }
      }

来看一下**isBlacklisted**做了什么

public static boolean isBlacklisted(ExtensionAttribute attribute, List<ExtensionAttribute>... blackLists) { 
        if (blackLists != null) { 
          for (List<ExtensionAttribute> blackList : blackLists) { 
            for (ExtensionAttribute blackAttribute : blackList) { 
            	//是否是默认属性
              if (blackAttribute.getName().equals(attribute.getName())) { 
              //命名空间是否一样
                if (blackAttribute.getNamespace() != null && attribute.getNamespace() != null && blackAttribute.getNamespace().equals(attribute.getNamespace()))
                  return true;
                if (blackAttribute.getNamespace() == null && attribute.getNamespace() == null)
                  return true;
              }
            }
          }
        }
        return false;
      }

**blackList取值**

/** * 用户节点默认通用属性 */
      protected static final List<ExtensionAttribute> defaultUserTaskAttributes = Arrays.asList(
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_FORM_FORMKEY),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_DUEDATE),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_BUSINESS_CALENDAR_NAME),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_ASSIGNEE),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_OWNER),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_PRIORITY),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_CANDIDATEUSERS),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_CANDIDATEGROUPS),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_CATEGORY),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_SERVICE_EXTENSIONID),
              //设置抄送为默认通用标签
              //new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_CANDIDATE_NOTIFY_USERS),
              new ExtensionAttribute(ACTIVITI_EXTENSIONS_NAMESPACE, ATTRIBUTE_TASK_USER_SKIP_EXPRESSION)
      );

在这里设置后测试一切OK。

[activiti-workflow]: https://github.com/heartlhj/activiti-workflow.git
[20200526145458201.png]: https://img-blog.csdnimg.cn/20200526145458201.png
[2020052615093151.png]: https://img-blog.csdnimg.cn/2020052615093151.png