java 两个对象数组进行去重 java两个数组相减

@PageResource(funcCode = "getSubRole", funcName = "getSubRole")
     @RequestMapping(value = "/getSubRole")
     @ResponseBody
     public String getSubRole(HttpServletRequest request,String userId) {
     //拿到商家子账户类型的所有角色集合rolelist
     List<Object[]> rolelist = roleService.getRoleByUserType("COMMERCIAL_SUB");
     //根据userId拿到该员工在auth_user_role对应的所有角色
     List<Object[]> userrole = roleService.getUserRoleByUserIdAndUserType(userId, "COMMERCIAL_SUB");
     String str = "";
     String xs = "";
     String As = "";
     if(rolelist!=null&&!"".equals(rolelist)&&!rolelist.isEmpty()){
     for(int i=0;i<rolelist.size();i++){
        As+=i+",";
        if(userrole!=null&&!"".equals(userrole)&&!userrole.isEmpty()){
        for(int j=0;j<userrole.size();j++){
        if(rolelist.get(i)[2].toString()==userrole.get(j)[3]||rolelist.get(i)[2].toString().equals(userrole.get(j)[3])){
        str+="<input type='checkbox' checked='checked' name='roleCode' value='"+rolelist.get(i)[2].toString()+"'/>"+rolelist.get(i)[1].toString()+"  ";
        xs+=i+",";//把有的权限就记录下来
        }
        }
        }else{
        str=str+"<input type='checkbox' name='roleCode' value='"+rolelist.get(i)[2].toString()+"'/>"+rolelist.get(i)[1].toString()+"  ";
        }
         }
     String[] A = As.split(",");
     String[] x = null;
   if(xs!=null) x=xs.split(",");
   List<String> listA= java.util.Arrays.asList(A); 
   List<String> listB= java.util.Arrays.asList(x); 
   Set setA = new HashSet(listA);
       setA.removeAll(listB);   
       Iterator iterator = setA.iterator();
   if(setA.size()>0){
       while(iterator.hasNext()){
   int ii = Integer.parseInt((String) iterator.next());
        str=str+"<input type='checkbox' name='roleCode' value='"+rolelist.get(ii)[2].toString()+"'/>"+rolelist.get(ii)[1].toString()+"  ";
   }
   }
     }
         return JsonUtil.toJSONString(str);
     }