Question

大家好我正在建立一个注册表单，我想将用户名存储在ArrayList

添加用户名很好，但是当我检查重复时，它仍会添加相同的用户名

到目前为止我的代码：

private void clickEventLeftPanel() {
        registerBtn.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                unameReg = registerUser.getText();
                regPass = registerPassword.getPassword();
                regRetype = registerRetype.getPassword();
                set = new ArrayList();
                if (unameReg.isEmpty()) {
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Username is Required", "Error", JOptionPane.ERROR_MESSAGE);
                } else if (regPass.length == 0) {
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Password is Required", "Error", JOptionPane.ERROR_MESSAGE);
                } else if (regPass.length < 6) {
                    weakness.setText("Very Weak");
                    weakness.setBackground(Color.red);
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Your password is very weak please enter a more complex password", "Error", JOptionPane.ERROR_MESSAGE);
                } else if (regPass.length < 8) {
                    weakness.setText("Moderate");
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Your password is moderate please enter a more complex password", "Error", JOptionPane.ERROR_MESSAGE);
                    weakness.setBackground(Color.yellow);
                } else if (regRetype.length == 0) {
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Please retype your password", "Error", JOptionPane.ERROR_MESSAGE);
                } else if (regPass != regRetype && regPass.length != regRetype.length) {
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Passwords do not match", "Error", JOptionPane.ERROR_MESSAGE);
                } else {
                    weakness.setText("Strong");
                    weakness.setBackground(Color.green);
                    if(set.contains(unameReg)){
                        System.err.println("Already exists");
                    }else{
                        set.add(unameReg);

                    }
                    JOptionPane.showMessageDialog(HomeAssignmentJavaLab.this, "Registration Successful user " + registerUser.getText() + " was entered", "Success", JOptionPane.PLAIN_MESSAGE);
                }

                weakness.setText("");
                weakness.setBackground(getBackground());
                registerUser.setText("");
                registerPassword.setText("");
                registerRetype.setText("");
            }


    });
    }

有什么想法吗？

Answer 1

每次添加set时都会创建unameReg。你必须创建一次。

检查Arraylist中是否存在用户名

1 个答案: