Question

I’m having a problem with retrieving and casting ArrayList from session. I get the following error:

    javax.servlet.ServletException: java.lang.IndexOutOfBoundsException: Index: 1, Size: 1

I stored the arrayList in the session:

    List<UserApplication> userList = uaDAO.searchUser(eds);
    if (!userList.isEmpty()) {
    request.getSession().setAttribute("userList", userList);
    action_forward = EDITSUCCESS;

and for casting the session object to ArrayList, did the following:

    EditStudentForm edt = (EditStudentForm)form;
    if ((session.getAttribute("userList")) instanceof List){
    List <UserApplication> studtList = (ArrayList<UserApplication>)session.getAttribute("userList");
    }
    try {
    uaDAO.editUser(edt,studtList);
    action_forward = EDITSUCCESS;
    }

I’m getting the error over here in the DAO class:

    public void editUser(EditStudentForm edt,List studtList) throws Exception {
    PreparedStatement pst = null;
    StringBuilder sb = new StringBuilder();
    int stCode =Integer.parseInt(studtList.get(1).toString());  GETTING ERROR HERE
    if (edt.getTitle() != null && !edt.getTitle().equals(studtList.get(2).toString())) {
    sb.append("title = '").append(edt.getTitle()).append("'");
    }
    .
    .

Answer 1

In this code:

 EditStudentForm edt = (EditStudentForm)form;
    if ((session.getAttribute("userList")) instanceof List){
    List <UserApplication> studtList = (ArrayList<UserApplication>)session.getAttribute("userList");
    }
    try {
    uaDAO.editUser(edt,studtList);
    action_forward = EDITSUCCESS;
    }

You create a new variable ‘studtList’ that is never used. It’s scope is only the { } pair around that one line.

There has to be another variable by that same name, studtList, in the outer scope so the ‘editUser()’ call can work.

Additional Note

As the other folks have answered, it looks like you may be doing a .get(1) and expecting the first element of the array list. Maybe. Maybe not.