Http请求传json数据中文乱码问题

业务场景：调easyui的dialog打开一个弹窗，传参是用json封装的，而且有中文，然后在极速模式是正常的，在ie11测试发现中文出现乱码了

var params = JSON.stringify(writParamList);
top.dialog({
			 id: 'noticeList',
			 title:'列表',
			 width:900,
			height:500,
			url:'${root}/notice/multiNoticeList.do?params='+params,
			onclose:function(){
						//location.reload();
			 }
}).showModal();

后台获取json数据，并转成list，然后在ie模式，获取到的json数据都出现中文乱码，然后导致json不能解析报错了

String params = request.getParameter("params");
		logger.info("文书参数转换前:》》"+params);
		params=StringEscapeUtils.unescapeJava(params);
		logger.info("文书参数转换后:》》"+params);
		ObjectMapper mapper = new ObjectMapper();
		JavaType javaType = mapper.getTypeFactory().constructParametricType(List.class, FormModel.class);
		/*List<FormModel> writUnionFormList = 
				JSON.parseArray(params, FormModel.class);*/
		List<FormModel> writUnionFormList=new ArrayList<FormModel>();
		try {
			writUnionFormList = (List<FormModel>)mapper.readValue(params, javaType);
		} catch (JsonParseException e) {
			e.printStackTrace();
		} catch (JsonMappingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}

针对上面问题，和同事讨论，最开始打算base64加密来传，然后发现base64加密中文出现问题，所以改成URLEncode的方式，前端加密两遍，后台在解密一遍

var params = JSON.stringify(writParamList);
top.dialog({
			 id: 'noticeList',
			 title:'列表',
			 width:900,
			height:500,
			url:'${root}/notice/multiNoticeList.do?params='+encodeURI(encodeURI(params)),
			onclose:function(){
						//location.reload();
			 }
}).showModal();

后台代码修改，解码一遍，然后发现在ie也正常

String params = request.getParameter("params");
		logger.info("文书参数转换前:》》"+params);
		//params=StringEscapeUtils.unescapeJava(params);
//		byte[] buffer=Base64Utils.decodeFromString(params);
//		params = new String(buffer);
		 try {
			 params=URLDecoder.decode(params,"utf-8");
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		}
		logger.info("文书参数转换后:》》"+params);
		ObjectMapper mapper = new ObjectMapper();
		JavaType javaType = mapper.getTypeFactory().constructParametricType(List.class, ApprWritUnionFormModel.class);
		/*List<FormModel> writUnionFormList = 
				JSON.parseArray(params, FormModel.class);*/
		List<FormModel> writUnionFormList=new ArrayList<FormModel>();
		try {
			writUnionFormList = (List<FormModel>)mapper.readValue(params, javaType);
		} catch (JsonParseException e) {
			e.printStackTrace();
		} catch (JsonMappingException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}