ANDROID读取VECTOR错误，

WEBSERVICE：
public Vector<Users> getUserInfo(){
DBConn db = new DBConn();
ResultSet re = db.excecQuery("select top 10 user_id,user_cname from sys_user");
List<Users> ltobject = new ArrayList<Users>();
System.out.println("DOC->output开始！");
Vector<Users> v = new Vector<Users>();
try{
while (re.next()){
Users u = new Users();
System.out.println(re.getString(1));
System.out.println(re.getString(2));
u.setUserid(re.getString(1));
u.setUserName(re.getString(2));
ltobject.add(u);
// ltobject
}
v.addAll(ltobject);
return v;

}catch(Exception e){
e.printStackTrace();
return null;
}

}andriod:
Vector<SoapObject> result = (Vector<SoapObject>)envelope.getResponse();
一到这个就报错，
java.lang.classcastexception:org.ksoap2.serialization.soapobject
soapobjectandroidwebservice