springboot中集成flowable过程中出现的问题

1.实现服务任务的监听事件，该实现类实现了JavaDelegate接口时，直接使用@Resource注入的bean是null

原因：flowable执行监听事件时，是通过反射获取bean的，此时该bean不在spring的管理中，需要使用ApplicationContext来获取bean

import org.apache.commons.lang3.Validate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Lazy;
import org.springframework.stereotype.Service;

@Service
@Lazy(false)
public class SpringContextHolder implements ApplicationContextAware, DisposableBean {

	private static ApplicationContext applicationContext = null;

	private static Logger logger = LoggerFactory.getLogger(SpringContextHolder.class);

	/**
	 * 取得存储在静态变量中的ApplicationContext.
	 */
	public static ApplicationContext getApplicationContext() {
		assertContextInjected();
		return applicationContext;
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	@SuppressWarnings("unchecked")
	public static <T> T getBean(String name) {
		assertContextInjected();
		return (T) applicationContext.getBean(name);
	}

	/**
	 * 从静态变量applicationContext中取得Bean, 自动转型为所赋值对象的类型.
	 */
	public static <T> T getBean(Class<T> requiredType) {
		assertContextInjected();
		return applicationContext.getBean(requiredType);
	}

	/**
	 * 清除SpringContextHolder中的ApplicationContext为Null.
	 */
	public static void clearHolder() {
		if (logger.isDebugEnabled()){
			logger.debug("清除SpringContextHolder中的ApplicationContext:" + applicationContext);
		}
		applicationContext = null;
	}

	/**
	 * 实现ApplicationContextAware接口, 注入Context到静态变量中.
	 */
	public void setApplicationContext(ApplicationContext applicationContext) {
//		logger.debug("注入ApplicationContext到SpringContextHolder:{}", applicationContext);
 		if (SpringContextHolder.applicationContext != null) {
 			logger.info("SpringContextHolder中的ApplicationContext被覆盖, 原有ApplicationContext为:" + SpringContextHolder.applicationContext);
 		}
		SpringContextHolder.applicationContext = applicationContext;
	}

	/**
	 * 实现DisposableBean接口, 在Context关闭时清理静态变量.
	 */
	public void destroy() throws Exception {
		SpringContextHolder.clearHolder();
	}

	/**
	 * 检查ApplicationContext不为空.
	 */
	private static void assertContextInjected() {
		Validate.validState(applicationContext != null, "applicaitonContext属性未注入, 请在applicationContext.xml中定义SpringContextHolder.");
	}
}

package com.insgeek.platform.flow.adapter.listener;

import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.stream.Collectors;

import javax.annotation.Resource;

import org.flowable.engine.delegate.DelegateExecution;
import org.flowable.engine.delegate.JavaDelegate;
import org.springframework.util.CollectionUtils;

import com.insgeek.boot.web.context.IdentityContext;
import com.insgeek.platform.flow.adapter.config.FlowConstants;
import com.insgeek.platform.flow.enums.ElementTypeEnum;
import com.insgeek.platform.flow.enums.ResultCodeEnum;
import com.insgeek.platform.flow.pojo.dto.ExtensionServiceTaskDto;
import com.insgeek.platform.flow.pojo.dto.ProcessModelDto;
import com.insgeek.platform.flow.pojo.model.ExtensionElementModel;
import com.insgeek.platform.flow.rpc.EventClientService;
import com.insgeek.platform.flow.service.ExtensionService;
import com.insgeek.platform.flow.service.ProcessModelService;
import com.insgeek.platform.flow.util.BusinessKeyUtil;
import com.insgeek.platform.flow.util.SpringContextHolder;
import com.insgeek.protocol.flow.dto.InteractBusinessRequestDto;

/**
 * @author jiangliangyou
 * @date 2020-11-25
 */
public class ServiceTaskImpl implements JavaDelegate {


    private EventClientService eventClientService = SpringContextHolder.getBean(EventClientService.class);
    private ExtensionService extensionService = SpringContextHolder.getBean(ExtensionService.class);;
    private ProcessModelService processModelService = SpringContextHolder.getBean(ProcessModelService.class);
    


    @Override
    public void execute(DelegateExecution execution) {

//        System.out.println("JavaDelegate : " + getClass().getSimpleName());
//        Map map = MapBuilder.of("getId", execution.getId())
//                .put("getProcessInstanceId", execution.getProcessInstanceId())
//                .put("getProcessDefinitionId", execution.getProcessDefinitionId())
//                .put("getVariableNames", String.join(",", execution.getVariableNames()))
//                .put("getCurrentActivityId", execution.getCurrentActivityId())
//                .put("getEventName", execution.getEventName())
//                .put("getParentId", execution.getParentId())
//                .put("getProcessInstanceBusinessKey", execution.getProcessInstanceBusinessKey())
//                .put("getRootProcessInstanceId", execution.getRootProcessInstanceId())
//                .put("getSuperExecutionId", execution.getSuperExecutionId())
//                .put("getSimpleName", execution.getClass().getSimpleName()).build();
//        System.out.println(JacksonUtils.writeAsString(map));
    	
        ProcessModelDto processModelDto = processModelService.findEnableProcessModelByDefinition(execution.getProcessDefinitionId());
        // 根据任务elementId和modelId查询额外扩展表获取事件列表，如果没有事件，直接返回
        ExtensionElementModel queryParams = new ExtensionElementModel();
        queryParams.setModelId(processModelDto.getId());
        queryParams.setElementId(execution.getCurrentActivityId());
        queryParams.setElementType(ElementTypeEnum.SERVICE_TASK.getValue());
        List<ExtensionElementModel> eventModelList = extensionService.getExtensionElementModelListByQuery(queryParams);
        if (CollectionUtils.isEmpty(eventModelList)) return;
        // 事件不为空,判断事件的执行条件是否为空
        List<Long> eventIds = eventModelList.stream()
                    .map(ExtensionServiceTaskDto::of)
                    .map(ExtensionServiceTaskDto::getTaskEventId)
                    .filter(Objects::nonNull)
                    .collect(Collectors.toList());
        Map<String,Object> variablesMap = execution.getVariables();
        InteractBusinessRequestDto interactBusinessRequestDto = new InteractBusinessRequestDto()
                .setCurrentTaskId(execution.getId())
                .setDataId(BusinessKeyUtil.dataId(execution.getProcessInstanceBusinessKey()))
                .setEntityKey(processModelDto.getEntityKey())
                .setApplicantId(Long.valueOf(String.valueOf(variablesMap.get(FlowConstants.APPLICANT_ID))))
                .setDefinitionId(execution.getProcessDefinitionId())
                .setVariables(variablesMap)
                .setCurrentUserId(IdentityContext.getUserId());
        eventClientService.executeEventByEventIds(eventIds, ResultCodeEnum.AFTER_EVENT_EXECUTION_ERROR,interactBusinessRequestDto);
    }
}