Activiti在linux上出现流程图中文乱码的问题

public InputStream tracePhoto(String processDefinitionId, String executionId) {
         
  		List<String> activeActivityIds = Lists.newArrayList(), highLightedFlows = new ArrayList<String>(); 		if (runtimeService.createExecutionQuery().executionId(executionId).count() > 0) {
         
  			activeActivityIds = runtimeService.getActiveActivityIds(executionId); 		} 		/** 		 * 获得当前活动的节点 		 */ 		if (this.isFinished(executionId)) {// 如果流程已经结束，则得到结束节点 			activeActivityIds.add(historyService.createHistoricActivityInstanceQuery().executionId(executionId) 					.activityType("endEvent").singleResult().getActivityId()); 		} else {// 如果流程没有结束，则取当前活动节点 			// 根据流程实例ID获得当前处于活动状态的ActivityId合集 			activeActivityIds = runtimeService.getActiveActivityIds(executionId); 		} 		// 获得历史活动记录实体（通过启动时间正序排序，不然有的线可以绘制不出来） 		List<HistoricActivityInstance> historicActivityInstances = historyService.createHistoricActivityInstanceQuery() 				.executionId(executionId).orderByHistoricActivityInstanceStartTime().asc().list(); 		// 计算活动线 		highLightedFlows = this 				.getHighLightedFlows((ProcessDefinitionEntity) ((RepositoryServiceImpl) repositoryService) 						.getDeployedProcessDefinition(processDefinitionId), historicActivityInstances); 		/** 		 * 绘制图形 		 */ 		InputStream imageStream = null; 		if (null != activeActivityIds) {
         
  			try {
         
  				// 获得流程引擎配置 				ProcessEngineConfiguration processEngineConfiguration = processEngine.getProcessEngineConfiguration(); 				// 根据流程定义ID获得BpmnModel 				BpmnModel bpmnModel = repositoryService.getBpmnModel(processDefinitionId); 				// 输出资源内容到相应对象 				imageStream = new DefaultProcessDiagramGenerator().generateDiagram(bpmnModel, "png", activeActivityIds, 						highLightedFlows, processEngineConfiguration.getActivityFontName(), 						processEngineConfiguration.getLabelFontName(), processEngineConfiguration.getClassLoader(), 						1.0); 				return imageStream; 			} catch (Exception e) {
         
  				e.printStackTrace(); 			} 		} 		return null; 	}

@RequestMapping(value = "editor/stencilset", 			method = RequestMethod.GET, produces = "application/json;charset=utf-8") 	@ResponseBody 	public String stencilset() {
         
  		InputStream stencilsetStream = this.getClass().getClassLoader().getResourceAsStream("stencilset.json"); 		try {
         
  			return IOUtils.toString(stencilsetStream, "utf-8"); 		} catch (Exception e) {
         
  			throw new RuntimeException("Error while loading stencil set", e); 		} finally {
         
  			IOUtils.closeQuietly(stencilsetStream); 		} 	}