一：Java class
Java class实现JavaDelegate接口，只需要配置类的全限定名即可，不需要被Spring容器管理。
public class JavaClassServiceTask implements JavaDelegate {@Overridepublic void execute(DelegateExecution execution) throws Exception {System.out.println("JavaClassServiceTask");String currentActivityId = execution.getCurrentActivityId();execution.setVariable(currentActivityId, "ok");}
}
二：Delegate expression
实现JavaDelegate接口，配置成Bean的名字即可。
@Service
public class DelegateExpressionServiceTask implements JavaDelegate {@Overridepublic void execute(DelegateExecution execution) throws Exception {System.out.println(execution.getVariable("JavaClass"));System.out.println("DelegateExpressionServiceTask");}
}
三：Expression
配置成普通的方法调用，可以是任意类的任意方法，方法的返回值会赋值给Result variable变量，该变量可以从下一个节点获取。
@Service
public class ExpressionServiceTask {public boolean execute(DelegateExecution execution) {System.out.println("ExpressionServiceTask");return true;}
}
四：External
@Configuration
public class CamundaHandlerConfig {@Bean@ExternalTaskSubscription(topicName = "java_external_task_topic",processDefinitionKeyIn = {"ServiceTaskProcess"},lockDuration = 5000)public ExternalTaskHandler externalTaskHandler() {return (ExternalTask externalTask, ExternalTaskService externalTaskService) -> {boolean expressionResult = (boolean)externalTask.getVariable("expressionResult");// 处理业务逻辑...if (!expressionResult) {externalTaskService.handleFailure(externalTask, "error msg...", "error detail...", 0, 5000);}Map<String, Object> variables = new HashMap<>();variables.put("result", 1);externalTaskService.complete(externalTask, variables);};}
}
# pip3 install camunda-external-task-client-python3
# pip3 install pydanticfrom camunda.external_task.external_task import ExternalTask, TaskResult
from camunda.external_task.external_task_worker import ExternalTaskWorkerdefault_config = {"maxTasks": 1, # 一次只拉一个任务，这样多实例处理就不会所有任务被一个实例锁住"lockDuration": 10000, # 锁任务的时间"asyncResponseTimeout": 30000,"retries": 0,"retryTimeout": 5000,"sleepSeconds": 30000, # 每次拉取的间隔时间"auth_basic": {"username": "admin", "password": "123456"}
}def handle_task(task: ExternalTask) -> TaskResult:result = task.get_variable("result")if result:return task.failure(error_message="error_message",error_details="error_details 如异常堆栈信息",max_retries=0, retry_timeout=5000)return task.complete()if __name__ == '__main__':worker = ExternalTaskWorker(worker_id="python-client",base_url="http://localhost:8080/engine-rest",config=default_config).subscribe("python_external_task_topic", handle_task)五：运行
- 启动工作流引擎
- 启动Java客户端
- 启动Python客户端
repositoryService.createDeployment().name("服务任务流程").addClasspathResource("bpmn/service_task.bpmn").deploy();identityService.setAuthenticatedUserId("huihui");
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("ServiceTaskProcess");
System.out.println("processInstance=" + processInstance.getId());
五：连接器
<dependency><groupId>org.camunda.bpm</groupId><artifactId>camunda-engine-plugin-connect</artifactId><version>${camunda.spring-boot.version}</version>
</dependency>
<dependency><groupId>org.camunda.connect</groupId><artifactId>camunda-connect-connectors-all</artifactId><version>1.5.6</version>
</dependency>
public class HttpConnectorConfigurator implements ConnectorConfigurator<HttpConnector> {public Class<HttpConnector> getConnectorClass() {return HttpConnector.class;}public void configure(HttpConnector connector) {CloseableHttpClient client = HttpClients.custom().setMaxConnPerRoute(10).setMaxConnTotal(200).build();((AbstractHttpConnector) connector).setHttpClient(client);}
}
在文件src/main/resources/META-INF/services/org.camunda.connect.spi.ConnectorConfigurator中配置以下完全限制类。
com.example.camunda.config.HttpConnectorConfigurator
