Struts2 Action 抛出异常无法正确跳转

try{
		if (file!=null&&file.length()>0){
			if(!wsFileUpload.isValidSize(file.length(),wsFileUpload.getLogoPicMaxSize())){throw new Exception("文件超出大小");}
			if(!wsFileUpload.isValidFile(fileContentType, wsFileUpload.getLogoPicType())){throw new Exception("类型不支持");}
			
//省略其它代码	
		}
		}catch(Exception e){
			//e.printStackTrace();
			//this.addFieldError("uploadErr", e.getMessage()); 该语句加入无法正确跳转到courseeditinfo这个结果
			this.getRequest().setAttribute("uploadErr", e.getMessage());
		}finally{
			this.setCsid(cs.getCourseId().toString());
			return "courseeditinfo";	
		}

原因何在？