I have a ClassCastException as well

[mike hengst]

When I run my client server project I am getting a ClassCastException error??? My method finds an employee by the ID, Here are the specs I am to use.
variables
ArrayList emps;
Employee emp; I have an Employee class
Test the map for the passed key
if found
set the emps var to the arraylist found by doing a get on the byId map using the passed arg
extract the one employee outof the map using the map's get(0) method
execute the employees toString() to represent this emp as a string and return the stringto the protocol
otherwise return string that says not found

here is the code:

     public String findByID(String id) {
        ArrayList     emps;
        Employee      emp;
        //testing if true
        if(byId.containsKey(id)) {
            emps = new ArrayList();
            // setting emps to the id
            emps.add((ArrayList)byId.get(id));
            System.out.println(emps + " emps = ((ArrayList)byId.get(id))");
            //emp = new Employee();
            emp = (Employee)emps.get(0);//error is here
            return emp.toString();
        }
        else {
            return "No employees found with the ID " + id;
        }
    }

[Jim Yingst]

Which line throws the exception? What exactly does it say? Usually the message will identify what class you were attempting to cast to, and what class was actually found. This is really useful information when debugging; don't overlook it.

[mike hengst]

Here is an updated code version, same error:

    public String findByID(String id) {
        ArrayList  emps;
        Employee   emp;
        //testing if true
        if(byId.containsKey(id)) {
            emps = new ArrayList();
            // setting emps to the id
            emps.add((ArrayList)(byId.get(id)));
            System.out.println(emps + " emps = ((ArrayList)byId.get(id))");
            //emp = new Employee();
            emp = (Employee)(emps.get(0)); //THE ERROR IS ON THIS LINE ERROR SAYS JAVA.LANG.CLASSCASTEXCEPTION: JAVA.UTIL.ARRAYLIST
            return emp.toString();
        }
        else {
            return "No employees found with the ID " + id;
        }
    }  

[Jim Yingst]

Looks like you're adding an ArrayList to an ArrayList, then taking it out and expecting it to have magically transformed into an Employee?

[mike hengst]

Hows this:

public String findByID(String id){
    ArrayList emps;
    Employee emp;
    String result;
    if(byId.containsKey(id)){
        
        System.out.println("has id = true");
        emps = (ArrayList)byId.get(id);
        
        emp = (Employee)emps.get(0);
        result= emp.toString(emps);
    }
    else{
        System.out.println("nosuch thing");
        result= "No employee found with the ID " + id; 
    }
    return result;

}  

It still does not work???

[mike hengst]

I have somewhat figured out??? However data is not displaying correctly. Can you look at this please, thank you. Here are the pertinent methods

public String findByID(String id){
    ArrayList emps;
    Employee emp;
    String result;
    if(byId.containsKey(id)){
        
        System.out.println("has id = true");
        emps = (ArrayList)byId.get(id);
        
        emp = (Employee)emps.get(0);
        System.out.println(emp.toString());
        result= emp.toString();
    }
    else{
        System.out.println("nosuch thing");
        result= "No employee found with the ID " + id; 
    }
    return result;

}
    public String toString() {
        System.out.println("in employee toString()");
        StringBuffer  sb  = new StringBuffer();
        sb.append(ID + "\t");
        sb.append(lName + "\t");
        sb.append(fName + "\t");
        sb.append(dept + "\t");
        return sb.toString();
    }
constructor for employee
    public Employee(String[] fields) {
        System.out.println("inside employee constructor");
        //System.out.println(fields + " fields");
        ID = fields[0];
        //System.out.println(ID);
        fName = fields[1];
        //System.out.println(lName);
        lName = fields[2];
        //System.out.println(fName);
        dept = fields[3];
        //System.out.println(dept);
    }
  

[Wirianto Djunaidi]

Mike,
When you said the data was not displayed right,
how do you want it display and how was it displayed currently?
-Ryo