Please Help!! A list with index

Question

Hi, I have used a list to get data from table called user in database. I used an object array to store all users in my program from db.
In the list I need to do remove item function. However, in the list I just can show the name of the user but not the user_id, which is the primary key of the table.
I think I can use mapping from the user name in list and array of object, but it may cause error, because it is not primay key. So what can I do?? Please help!!! Thanks!!

Answer 1

You will need to override equals() and toString() methods.
public class User {
    public String userName;
    public String userId;
    public boolean equals(Object obj) {
       if(obj instanceof User) {
           User that = (User)obj;
           if(that.userId.equals(this.userId)) {
              return true;
        return false;
    public String toString() {
        return this.userName;
}Hope that helps.
Vijay