Java com.google.firebase.internal.api.FirebaseNoSignedInUserException:请在尝试获取令牌之前登录

我第一次尝试将pdf上载到实时数据库。因此，上载的pdf文件已加载。但我正在查找实时数据库，它没有显示pdf url和其他详细信息。然后检查日志，我发现此错误

错误

.Assignment.java

储藏

格拉德尔

---

{“规则”：{.read:true，.write:true}我不明白这一点，你能解释一下更多细节吗？2020-09-18 15:53:01.704 30861-30977/com.example.projectx E/StorageUtil:获取令牌时出错java.util.concurrent.ExecutionException:com.google.firebase.internal.api.FirebaseNoSignedInUserException:请在尝试获取令牌之前登录。（logcat仅显示这一点。它不显示哪一行出现错误）

 2020-09-18 15:52:59.471 30861-30975/com.example.projectx E/StorageUtil: error getting token java.util.concurrent.ExecutionException: com.google.firebase.internal.api.FirebaseNoSignedInUserException: Please sign in before trying to get a token.

package com.example.projectx.buddhika;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import android.app.ProgressDialog;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.example.projectx.R;
import com.example.projectx.kavishka.Pp;
import com.example.projectx.rasuni.Marks;
import com.example.projectx.yasasri.Project;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
import com.google.android.gms.tasks.Task;
import com.google.android.material.bottomnavigation.BottomNavigationView;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Logger;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.OnProgressListener;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.UploadTask;

public class Assignment extends AppCompatActivity {

    private Button button;

    Button btn_upload1;
    EditText txt_year;
    EditText txt_semester;
    EditText txt_name1;
    EditText txt_subject;

    StorageReference storageReference;
    DatabaseReference databaseReference;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_assignment);


        btn_upload1 = (Button) findViewById(R.id.ass_upload_btn);
        txt_year = (EditText) findViewById(R.id.ass_txt_year);
        txt_semester = (EditText) findViewById(R.id.ass_txt_semester);
        txt_name1 = (EditText)findViewById(R.id.ass_txt_name11);
        txt_subject = (EditText) findViewById(R.id.ass_txt_subject);


        button = (Button) findViewById(R.id.view);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(Assignment.this, Edit_assignment.class);
                startActivity(intent);
            }
        });





        //intialize and assign variable
        BottomNavigationView bottomNavigationView = findViewById(R.id.bottom_navigation);

        //set home selected
        bottomNavigationView.setSelectedItemId(R.id.assignment);

        //perform itemselected list
        bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
                switch (menuItem.getItemId()) {
                    case R.id.marks:
                        startActivity(new Intent(getApplicationContext(), Marks.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.todo:
                        startActivity(new Intent(getApplicationContext(), MainActivity2.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.assignment:

                        return true;
                    case R.id.project:
                        startActivity(new Intent(getApplicationContext(), Project.class));
                        overridePendingTransition(0, 0);
                        return true;
                    case R.id.pp:
                        startActivity(new Intent(getApplicationContext(), Pp.class));
                        overridePendingTransition(0, 0);
                        return true;
                }
                return false;
            }

        });


        storageReference = FirebaseStorage.getInstance().getReference();
        databaseReference = FirebaseDatabase.getInstance().getReference("uploads");


        btn_upload1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                selectPDFFile();
            }
        });



    }


    private void selectPDFFile() {

        Intent intent = new Intent();
        intent.setType("application/pdf");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent,"Select PDF File"),1);
    }


    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (requestCode == 1 && resultCode == RESULT_OK
                && data !=null && data.getData()!=null)
        {
            uploadPDFFile(data.getData());

        }

    }

    private void uploadPDFFile(Uri data) {

        final ProgressDialog processDialog = new ProgressDialog(this);
        processDialog.setTitle("Uploading...");
        processDialog.show();

        StorageReference reference = storageReference.child("uploads/"+System.currentTimeMillis()+".pdf");
        reference.putFile(data).addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {


                Task<Uri> uri = taskSnapshot.getStorage().getDownloadUrl();
                while (!uri.isComplete());
                Uri url = uri.getResult();

                Upload_pdf Upload_pdf = new Upload_pdf(txt_name1.getText().toString(),url.toString());

                databaseReference.child(databaseReference.push().getKey()).setValue(Upload_pdf);

                Toast.makeText(Assignment.this,"File Upload",Toast.LENGTH_SHORT);
                processDialog.dismiss();
            }
        }).addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
            @Override
            public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {

                double progress = (100.0 * taskSnapshot.getBytesTransferred())/taskSnapshot.getTotalByteCount();
                processDialog.setMessage("Uploaded:"+(int)progress+"%");

            }
        });


    }
}

   {
      "rules": {
        ".read": true,
        ".write": true
      }
    }

rules_version = '2';
service firebase.storage {
  match /b/{bucket}/o {
    match /{allPaths=**} {
      allow read, write;
    }
  }
}

apply plugin: 'com.android.application'
apply plugin: 'com.google.gms.google-services'

android {
    compileSdkVersion 30
    buildToolsVersion "30.0.1"

    defaultConfig {
        applicationId "com.example.projectx"
        minSdkVersion 21
        targetSdkVersion 30
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: "libs", include: ["*.jar"])
    implementation 'androidx.appcompat:appcompat:1.1.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'com.google.firebase:firebase-auth:16.0.4'
    implementation 'com.google.firebase:firebase-database:16.0.4'
    implementation 'androidx.navigation:navigation-fragment:2.3.0'
    implementation 'androidx.navigation:navigation-ui:2.3.0'
    implementation 'androidx.legacy:legacy-support-v4:1.0.0'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'com.google.firebase:firebase-storage:16.0.4'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    implementation 'com.android.support:cardview-v7:+'


}