Ajax在springMVC中实现前后台交互（后台返回字符串）

后台：controller方法里面：

Tribe tribe = tribedao.selectVipUserByTribeid(map);
String username = tribe.getCreateusermap().getRealname();
int userid = tribe.getCreateuserid();
return "{\"username\":\"" + username + "\",\"userid\":\"" + userid
+ "\"}";

前台：

$.ajax({
url:"searchTribeLikeName.do",
async:false,
type:"post",
dataType:"JSON",
data:{"name":'',"id":tribeid},
success:function(data){
$("#realname").val(data.username);
$("#userid").find("option:nth-child(n+2)").remove();//获取从第二个option选择项开始之后所有的选择项
var str="<option value='"+data.userid+"' selected='selected'>"+data.username+"</option>";
$("#userid").append(str);
},
error:function (){
alert("error1")
}
});