Activiti6生成实例历史活动追踪图片

　　最近要把Activiti6集成到系统中，遇到了生成追踪流程图片的问题，在5.x版本中可以使用历史流程节点查找ActivityImpl，升级到6.0版本后，pvm包被移除，所以要实现新的图片生成办法。本文灵感来自：Activiti6.0.0 跟踪流程执行情况用红色框在流程图上标识路线跟节点

　　生成追踪流程图要完成两件事情：已执行的Activity高亮和已流转的Flow高亮。

　　以下方法是生成完整的追踪图片：

    public InputStream getResourceDiagramInputStream(String id) {
        try {
            // 获取历史流程实例
            HistoricProcessInstance historicProcessInstance = historyService.createHistoricProcessInstanceQuery().processInstanceId(id).singleResult();
                        
            // 获取流程中已经执行的节点，按照执行先后顺序排序
            List<HistoricActivityInstance> historicActivityInstanceList = historyService.createHistoricActivityInstanceQuery().processInstanceId(id).orderByHistoricActivityInstanceId().asc().list();
            
            // 构造已执行的节点ID集合
            List<String> executedActivityIdList = new ArrayList<String>();
            for (HistoricActivityInstance activityInstance : historicActivityInstanceList) {
                executedActivityIdList.add(activityInstance.getActivityId());
            }
            
            // 获取bpmnModel
            BpmnModel bpmnModel = repositoryService.getBpmnModel(historicProcessInstance.getProcessDefinitionId());
            // 获取流程已发生流转的线ID集合
            List<String> flowIds = this.getExecutedFlows(bpmnModel, historicActivityInstanceList);
            
            // 使用默认配置获得流程图表生成器，并生成追踪图片字符流
            ProcessDiagramGenerator processDiagramGenerator = processEngine.getProcessEngineConfiguration().getProcessDiagramGenerator();
            InputStream imageStream = processDiagramGenerator.generateDiagram(bpmnModel, "png", executedActivityIdList, flowIds, "宋体", "微软雅黑", "黑体", null, 2.0);
            return imageStream;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

　　以下方法获取所有已流转的线，由于并行网关与包含网关可能存在多个流转，所以要找到全部符合要求的Flow，其它类型的节点只查找历史活动实例中的第一个节点：

    private List<String> getExecutedFlows(BpmnModel bpmnModel, List<HistoricActivityInstance> historicActivityInstances) {
        // 流转线ID集合
        List<String> flowIdList = new ArrayList<String>();
        // 全部活动实例
        List<FlowNode> historicFlowNodeList = new LinkedList<FlowNode>();
        // 已完成的历史活动节点
        List<HistoricActivityInstance> finishedActivityInstanceList = new LinkedList<HistoricActivityInstance>();
        for (HistoricActivityInstance historicActivityInstance : historicActivityInstances) {
            historicFlowNodeList.add((FlowNode) bpmnModel.getMainProcess().getFlowElement(historicActivityInstance.getActivityId(), true));
            if (historicActivityInstance.getEndTime() != null) {
                finishedActivityInstanceList.add(historicActivityInstance);
            }
        }
        
        // 遍历已完成的活动实例，从每个实例的outgoingFlows中找到已执行的
        FlowNode currentFlowNode = null;
        for (HistoricActivityInstance currentActivityInstance : finishedActivityInstanceList) {
            // 获得当前活动对应的节点信息及outgoingFlows信息
            currentFlowNode = (FlowNode) bpmnModel.getMainProcess().getFlowElement(currentActivityInstance.getActivityId(), true);
            List<SequenceFlow> sequenceFlowList = currentFlowNode.getOutgoingFlows();
            
            /**
             * 遍历outgoingFlows并找到已流转的
             * 满足如下条件认为已流转：
             * 1.当前节点是并行网关或包含网关，则通过outgoingFlows能够在历史活动中找到的全部节点均为已流转
             * 2.当前节点是以上两种类型之外的，通过outgoingFlows查找到的时间最近的流转节点视为有效流转
             */
            FlowNode targetFlowNode = null;
            if (BpmsActivityTypeEnum.PARALLEL_GATEWAY.getType().equals(currentActivityInstance.getActivityType())
                    || BpmsActivityTypeEnum.INCLUSIVE_GATEWAY.getType().equals(currentActivityInstance.getActivityType())) {
                // 遍历历史活动节点，找到匹配Flow目标节点的
                for (SequenceFlow sequenceFlow : sequenceFlowList) {
                    targetFlowNode = (FlowNode) bpmnModel.getMainProcess().getFlowElement(sequenceFlow.getTargetRef(), true);
                    if (historicFlowNodeList.contains(targetFlowNode)) {
                        flowIdList.add(sequenceFlow.getId());
                    }
                }
            } else {
                List<Map<String, String>> tempMapList = new LinkedList<Map<String,String>>();
                // 遍历历史活动节点，找到匹配Flow目标节点的
                for (SequenceFlow sequenceFlow : sequenceFlowList) {
                    for (HistoricActivityInstance historicActivityInstance : historicActivityInstances) {
                        if (historicActivityInstance.getActivityId().equals(sequenceFlow.getTargetRef())) {
                            tempMapList.add(UtilMisc.toMap("flowId", sequenceFlow.getId(), "activityStartTime", String.valueOf(historicActivityInstance.getStartTime().getTime())));
                        }
                    }
                }
                
                // 遍历匹配的集合，取得开始时间最早的一个
                long earliestStamp = 0L;
                String flowId = null;
                for (Map<String, String> map : tempMapList) {
                    long activityStartTime = Long.valueOf(map.get("activityStartTime"));
                    if (earliestStamp == 0 || earliestStamp >= activityStartTime) {
                        earliestStamp = activityStartTime;
                        flowId = map.get("flowId");
                    }
                }
                flowIdList.add(flowId);
            }
        }
        return flowIdList;
    }

　　枚举说明：

public enum BpmsActivityTypeEnum {
    
    START_EVENT("startEvent", "开始事件"),
    END_EVENT("endEvent", "结束事件"),
    USER_TASK("userTask", "用户任务"),
    EXCLUSIVE_GATEWAY("exclusiveGateway", "排他网关"),
    PARALLEL_GATEWAY("parallelGateway", "并行网关"),
    INCLUSIVE_GATEWAY("inclusiveGateway", "包含网关");
    
    private String type;
    private String name;
    
    private BpmsActivityTypeEnum(String type, String name) {
        this.type = type;
        this.name = name;
    }
    
    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

　　工具方法：

public class UtilMisc {
    public static <V, V1 extends V, V2 extends V> Map<String, V> toMap(String name1, V1 value1, String name2, V2 value2) {
        return populateMap(new HashMap<String, V>(), name1, value1, name2, value2);
    }
    @SuppressWarnings("unchecked")
    private static <K, V> Map<String, V> populateMap(Map<String, V> map, Object... data) {
        for (int i = 0; i < data.length;) {
            map.put((String) data[i++], (V) data[i++]);
        }
        return map;
    }
}

　　看一个简单的生成效果：

　　在按照流程节点类型做区分处理上，考虑的不是特别周全，希望有用到的朋友遇到了问题能够与我分享，一起探讨更好的解决方式~