ajax向后台传递参数数组

var data = document.getElementById(‘role‘);    
var arrs =new Array();
for(var i=0;i<data.options.length;i++){            
    arrs.push(data.options[i].value);                            
}

var userId = $("#user").val();
if(arrs.length!=0){
    $.ajax({
        type: "POST",
        url: "/userRole/saveOrUpdate",                  
        data: {"userId":userId,"arr":arrs},
        traditional:true,
        async: true,
        dataType:"json",
        success: function(data){
        },
        error: function(){
        }
    });
}

public String saveOrUpdate( String userId, HttpServletRequest request) {
       String[] arr=request.getParameterValues("arr");
　　　　System.out.println(arr);
}