java.lang.NullPointerException：尝试调用虚拟方法“java.lang.String com.google.firebase.auth.FirebaseUser.getUid()”
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原文地址: http://stackoverflow.com/questions/44979970/
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StackOverFlow
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.google.firebase.auth.FirebaseUser.getUid()'
提问by Nub Doto
Process: com.example.vicevirus.myapplication, PID: 13471
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.google.firebase.auth.FirebaseUser.getUid()' on a null object reference
at com.example.vicevirus.myapplication.RegisterActivity.onComplete(RegisterActivity.java:48)
at com.google.android.gms.tasks.zzc.run(Unknown Source)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6119)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
This is on android monitor. How do I solve this?
这是在安卓显示器上。我该如何解决这个问题？
package com.example.vicevirus.myapplication;
import android.app.ProgressDialog;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
public class RegisterActivity extends AppCompatActivity {
private EditText email,name,password;
DatabaseReference databaseReference;
FirebaseAuth mAuth;
private DatabaseReference userIdRef;
ProgressDialog registerDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
email=(EditText)findViewById(R.id.email);
name=(EditText)findViewById(R.id.name);
password=(EditText)findViewById(R.id.password);
databaseReference= FirebaseDatabase.getInstance().getReference().child("chat_users");
mAuth=FirebaseAuth.getInstance();
registerDialog=new ProgressDialog(this);
registerDialog.setMessage("Registering..");
}
public void submit(View view) {
registerDialog.show();
mAuth.createUserWithEmailAndPassword(email.getText().toString(),password.getText().toString()).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
@Override
public void onComplete(@NonNull Task<AuthResult> task) {
if(task.isComplete())
{
registerDialog.dismiss();
Toast.makeText(getApplicationContext(),"Registered successfully",Toast.LENGTH_SHORT).show();
userIdRef=databaseReference.child(mAuth.getCurrentUser().getUid());
userIdRef.child("name").setValue(name.getText().toString());
finish();
}
registerDialog.dismiss();
}
});
}
}
回答by M0CH1R0N
The problem seems to be that your user is not yet logged in or even registered. So calling mAuth.getCurrentUser()returns null.
问题似乎是您的用户尚未登录甚至尚未注册。所以调用mAuth.getCurrentUser()返回null。
Check out this page of the FireBase documentationabout how you need to implement the registering of users. It could be that this is failing. The check task.isSuccessful()is necessary to check this.
查看FireBase 文档的这个页面，了解您需要如何实现用户注册。这可能是失败的。检查task.isSuccessful()是必要的检查。
