Activiti 流程圖查看完整實現：部署資源、當前節點高亮、Web 整合

核心 API

• RepositoryService：管理流程定義部署資源 (BPMN XML、PNG 圖片)。
• RuntimeService：查詢執行中流程實例、當前活動節點。
• TaskService：查詢待辦任務、關聯流程實例。

場景一：獨立查看部署圖片

public void viewDeployedImage(String deploymentId) throws IOException {
    // 1. 取得部署下所有資源名稱
    List<String> names = repositoryService.getDeploymentResourceNames(deploymentId);
    String imageName = names.stream().filter(n -> n.endsWith(".png")).findFirst().orElse(null);
    if (imageName == null) throw new IllegalStateException("無流程圖片");

    // 2. 讀取圖片輸入流
    InputStream in = repositoryService.getResourceAsStream(deploymentId, imageName);
    // 3. 輸出到檔案或 HTTP 響應
    Files.copy(in, Paths.get("D:/" + imageName), StandardCopyOption.REPLACE_EXISTING);
}

場景二：Web 頁面直接顯示圖片

@GetMapping("/process/image")
public void viewImage(@RequestParam String deploymentId,
                      @RequestParam String imageName,
                      HttpServletResponse resp) throws IOException {
    InputStream in = repositoryService.getResourceAsStream(deploymentId, imageName);
    resp.setContentType("image/png");
    IOUtils.copy(in, resp.getOutputStream());
}
// 前端: 

場景三：查看當前任務對應流程圖並高亮節點

1. 取得流程定義：ProcessDefinition pd = repositoryService.createProcessDefinitionQuery().processDefinitionId(task.getProcessDefinitionId()).singleResult();
2. 取得當前活動 ID：
   

   ProcessInstance pi = runtimeService.createProcessInstanceQuery()
           .processInstanceId(task.getProcessInstanceId()).singleResult();
   String currentActivityId = pi.getActivityId();

3. 解析座標：
   

   ProcessDefinitionEntity pde = (ProcessDefinitionEntity) repositoryService.getProcessDefinition(pd.getId());
   ActivityImpl activity = pde.findActivity(currentActivityId);
   // 座標: activity.getX(), getY(), getWidth(), getHeight()

4. 前端繪製高亮：
   後端返回 JSON `{deploymentId, imageName, x, y, width, height}`。
   前端 `` 疊加 `
   ` 定位高亮框。

完整 Controller 範例

@RestController
@RequestMapping("/activiti")
public class ProcessImageController {
    @Autowired RepositoryService repositoryService;
    @Autowired RuntimeService runtimeService;
    @Autowired TaskService taskService;

    @GetMapping("/current-image")
    public Map<String, Object> currentImage(@RequestParam String taskId) {
        Task task = taskService.createTaskQuery().taskId(taskId).singleResult();
        ProcessInstance pi = runtimeService.createProcessInstanceQuery()
                .processInstanceId(task.getProcessInstanceId()).singleResult();
        ProcessDefinition pd = repositoryService.createProcessDefinitionQuery()
                .processDefinitionId(task.getProcessDefinitionId()).singleResult();

        ProcessDefinitionEntity pde = (ProcessDefinitionEntity) repositoryService.getProcessDefinition(pd.getId());
        ActivityImpl act = pde.findActivity(pi.getActivityId());

        Map<String, Object> result = new HashMap<>();
        result.put("deploymentId", pd.getDeploymentId());
        result.put("imageName", pd.getDiagramResourceName());
        result.put("x", act.getX());
        result.put("y", act.getY());
        result.put("width", act.getWidth());
        result.put("height", act.getHeight());
        return result;
    }
}

注意事項

• 圖片生成：部署時需設定 createDiagramOnDeploy=true (預設) 或手動生成 PNG。
• 字體：Linux 伺服器需安裝中文字體 (如 wqy-zenhei)，否則圖片中文顯示方塊。
• 多實例/子流程：pi.getActivityId() 可能返回多實例主體節點，需根據業務判斷高亮範圍。