1 现象

浏览器客户端页面charset是GBK

<Meta http-equiv="content-type" content="text/html; charset=GBK" />

String roleName = request.getParameter(ROLE_NAME_PARAM);

String charset = request.getCharacterEncoding();

2 修改后，解决乱码

    jQuery.ajax({
        url: path,type: "POST",dataType:'json',contentType: "application/x-www-form-urlencoded; charset=utf-8",// 增加这一行
	data:{'type' : type,'roleName' : roleName,'roleId' : roleId},success:function(json) {
         
        },error:function(er){
           var err = eval("(" + xhr.responseText + ")");
           alert(err.Message);
        }
    });