如何使用数据结构链表更改Jtextfield或JComboBox中的值？

Question

I already used the set method in a LinkedList to change a value but it is not working for me. Everytime it will print the values in the console, it results to the same values. It doesn't change at all. Can anyone help me? Thank you!

Here's my code:

btnUpdate.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            for(int i = 0; i < emp.id.size(); i++){
                if(emp.id.get(i).equals(textField_6.getText())){
                    Employee emp = new Employee();

                    emp.setFirstname(textField_1.getText());
                    emp.setLastname(textField_2.getText());
                    emp.setAge(textField_3.getText());
                    emp.setGender(comboBox.getSelectedItem());
                    emp.setDesignation(comboBox_4.getSelectedItem());


                    emp.fName.set(i, emp.getFirstname());
                    emp.LName.set(i, emp.getLastname());
                    emp.Age.set(i, emp.getAge());
                    emp.Gender.set(i, emp.getGender());
                    emp.Designation.set(i, emp.getDesignation());
                }
            }

            JOptionPane.showMessageDialog(null, "Successfully changed!");

            System.out.println(emp.id);
            System.out.println(emp.fName);
            System.out.println(emp.LName);
            System.out.println(emp.Age);
            System.out.println(emp.Gender);
            System.out.println(emp.Designation);

            String cmd = e.getActionCommand();

            if(cmd.equals("Update")){
                dispose();
                exit();
            }
        }
    });

Answer 1

Employee emp = new Employee();

You are not updating an existing object, you are creating a new object and you never all the object to the LinkedList.

if(emp.id.get(i).equals(textField_6.getText())){

You have the if condition to find the "emp" object you want to update, so use that object.