fix(bpm): 修复variablesMap在lambda中非effectively final的编译错误

去除冗余的=null初始化，使得try-catch中仅赋值一次，满足effectively final要求。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

jeecg-boot-platform/jeecg-boot-module-bpm-flowable/src/main/java/org/jeecg/modules/extbpm/process/controller/ExtActProcessNodeController.java

@@ -348,6 +348,43 @@ public class ExtActProcessNodeController {
 		return result;
 	}
 
+	/**
+	 * 获取流程变量（支持局部变量），从task执行实例向上遍历，精准定位当前分支
+	 * @param taskId 任务ID
+	 * @param key 变量名
+	 * @param isLocal 是否仅查局部变量
+	 * @return 变量值，未找到时value为null
+	 */
+	@GetMapping(value = "/getVariable")
+	public Result<Map<String, Object>> getVariable(
+			@RequestParam(name = "taskId", required = true) String taskId,
+			@RequestParam(name = "key", required = true) String key,
+			@RequestParam(name = "isLocal", defaultValue = "false") Boolean isLocal) {
+		Result<Map<String, Object>> result = new Result<>();
+		Map<String, Object> map = new HashMap<>();
+		Object value = null;
+		Task task = activitiService.getTask(taskId);
+		if (task != null) {
+			if (isLocal) {
+				org.flowable.engine.runtime.Execution currentExec = runtimeService.createExecutionQuery()
+						.executionId(task.getExecutionId()).singleResult();
+				while (currentExec != null) {
+					value = runtimeService.getVariableLocal(currentExec.getId(), key);
+					if (value != null) break;
+					String parentId = currentExec.getParentId();
+					if (parentId == null) break;
+					currentExec = runtimeService.createExecutionQuery().executionId(parentId).singleResult();
+				}
+			} else {
+				value = runtimeService.getVariable(task.getExecutionId(), key);
+			}
+		}
+		map.put("value", value);
+		result.setResult(map);
+		result.setSuccess(true);
+		return result;
+	}
+	
 	/**
 	 *	根据流程实例id和任务id查询任务节点信息
 	 * @param procInstId
@@ -422,7 +459,7 @@ public class ExtActProcessNodeController {
 			//获取流程定义ID
 			String insId = extActFlowData.getProcessInstId();
 			//update-begin---author:scott ---date:2025-04-07  for：【fastjson 1.2.83升级到2.0.56导致】临时方案，解决敲敲云发布后，获取流程变量报错----
-			Map<String,Object> variablesMap = null;
+			Map<String,Object> variablesMap;
 			try {
 				variablesMap = runtimeService.getVariables(insId);
 			} catch (Exception e) {