如何使用android studio在firebase中设置孩子丢失的错误信息

Question

我在做一个关于能源监测的应用程序。在我的注册屏幕上，有四个编辑文本（全名、用户名、电子邮件、密码），一旦注册成功，将发送/存储到firebase。数据将由子用户名存储（类似于这样）在这里输入image description

esp32连接到firebase，它将在名为totalEnergy的用户名下存储一个子用户（这是一个int而不是字符串）。（类似这样）在这里输入图像描述

下面是示例代码。

    public void loginUser(View view) {

    //validate login info
    if (!validateUsername() | !validatePassword()) {
        return;
    } else {
        progressBar.setVisibility(View.VISIBLE);
        isUser();
    }


}

private void isUser() {

    final String userEnteredUsername = username.getEditText().getText().toString().trim();
    final String userEnteredPassword = password.getEditText().getText().toString().trim();

    rootNode = FirebaseDatabase.getInstance();
    reference = rootNode.getReference("USER INFO");

    Query checkUser = reference.orderByChild("username").equalTo(userEnteredUsername);

    checkUser.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {
            if (snapshot.exists()) {

                username.setError(null);
                username.setErrorEnabled(false);

                String passwordFromDB = snapshot.child(userEnteredUsername).child("password").getValue(String.class);

                if (passwordFromDB.equals(userEnteredPassword)) {

                    username.setError(null);
                    username.setErrorEnabled(false);

                    String fullNameFromDB = snapshot.child(userEnteredUsername).child("fullName").getValue(String.class);
                    String usernameFromDB = snapshot.child(userEnteredUsername).child("username").getValue(String.class);
                    String emailFromDB = snapshot.child(userEnteredUsername).child("email").getValue(String.class);

                    Intent intent = new Intent(getApplicationContext(), UserDashboard.class);
                    Bundle extras = new Bundle();

                    int totalEnergyFromDB = snapshot.child(userEnteredUsername).child("totalEnergy").getValue(int.class);

                        intent.putExtra("fullName", fullNameFromDB);
                        intent.putExtra("username", usernameFromDB);
                        intent.putExtra("email", emailFromDB);
                        intent.putExtra("password", passwordFromDB);
                        
                        extras.putString("totalEnergy", totalEnergyFromDB + "");
                        intent.putExtras(extras);

                        startActivity(intent);


                } else {
                    progressBar.setVisibility(View.GONE);
                    password.setError("Wrong Password!");
                    password.requestFocus();
                }
            } else {
                progressBar.setVisibility(View.GONE);
                username.setError("No such user exist!");
                username.requestFocus();
            }
        }

        @Override
        public void onCancelled(@NonNull DatabaseError error) {
            progressBar.setVisibility(View.GONE);
            Toast.makeText(Login.this, error.getMessage(), Toast.LENGTH_SHORT).show();
        }
    });
}

我已经做了一个星期了，我想不通！（请帮忙！！！谢谢！

你好Hb。这是错误：（在这里输入图像描述

Answer 1

您可以检查ESP32是否不是-1，如果不是则继续，如下所示：

java prettyprint-override">if (passwordFromDB.equals(userEnteredPassword)) { 
    username.setError(null);
    username.setErrorEnabled(false); 
    String fullNameFromDB = snapshot.child(userEnteredUsername).child("fullName").getValue(String.class); 
    String usernameFromDB = snapshot.child(userEnteredUsername).child("username").getValue(String.class); 
    String emailFromDB = snapshot.child(userEnteredUsername).child("email").getValue(String.class); 

    int totalEnergyFromDB = -1;

    try {
        totalEnergyFromDB = snapshot.child(userEnteredUsername).child("totalEnergy").getValue(int.class);
    } catch (Exception e){
        e.printStackTrace();
    }

    if (totalEnergyFromDB != -1) {
        Intent intent = new Intent(getApplicationContext(), UserDashboard.class); 
        Bundle extras = new Bundle();
        intent.putExtra("fullName", fullNameFromDB); 
        intent.putExtra("username", usernameFromDB); 
        intent.putExtra("email", emailFromDB); 
        intent.putExtra("password", passwordFromDB); 
        extras.putString("totalEnergy", totalEnergyFromDB + ""); 
        intent.putExtras(extras);
        startActivity(intent); 
    } else {
        Toast.makeText(Login.this, "Your account is not yet ready! Please try again later", Toast.LENGTH_SHORT).show();
    }
}