数组相减java

@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()+"&nbsp;&nbsp;";
       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()+"&nbsp;&nbsp;";
       }
        }
    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()+"&nbsp;&nbsp;";
  }
  }
    }
        return JsonUtil.toJSONString(str);
    }