#firebase storage

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Firebase Storage - Uploading and Downloading PDF Files

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I got many messages asking how to store and fetch PDF files in Firebase Storage. So here is the detailed post explaining about Uploading PDF files in Firebase Storage and Fetching those uploaded files from Firbase Storage. I already posted a tutorial about the same thing but with image files. You can check that post from the below link.

Firebase Storage – Uploading and Retrieving Images

Important: If you have no idea about Firebase Database and Firebase Storage, then it is highly recommended that go through the previous post from the link given above first. As I will not be explaining here about setting ab Firebase Storage and Database in the project. These things are well explained in the post given above. So please go through that first. 

Contents

1 Creating a New Project

2 Creating UI

2.1 MainActivity

2.2 View Uploads Screen

3 Creating Helper Classes

4 Uploading PDF in Firebase Storage

4.1 Changing Firebase Storage and Database Rules

4.1.1 Firebase Storage Rules

4.1.2 Firebase Database Rules

4.2 Testing the Upload

5 Retrieving Files from Firebase Storage

6 Download Source Code

Creating a New Project

So again we will start by creating a new project. I just created a project named FirebaseStorage.

After creating the project add Firebase Storage and Firebase Database to your project (Go to tools->firebase).

Creating UI

We have only two screens for this application. The first is the activity_main.xml which is created by default. And create one more Activity named ViewUploadsActivity.java.

In the first activity we will upload files to firebase storage and in the second activity we will display a list of all the uploaded files.

MainActivity

Open your activity_main.xml and write the following xml code.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:padding="16dp" tools:context="net.simplifiedlearning.firebasestorage.MainActivity"> <EditText android:id="@+id/editTextFileName" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_centerVertical="true" android:hint="Enter a name for your file" android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" /> <Button android:id="@+id/buttonUploadFile" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/editTextFileName" android:text="Upload PDF" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:orientation="vertical"> <ProgressBar android:id="@+id/progressbar" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:visibility="gone" /> <TextView android:id="@+id/textViewStatus" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="No file selected" android:textAlignment="center" android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" /> <TextView android:id="@+id/textViewUploads" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="10dp" android:text="View Uploads" android:textAlignment="center" android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" android:textColor="@color/colorPrimaryDark" /> </LinearLayout> </RelativeLayout>

The above code will generate the following screen.

activity_main.xml

You can see the layout is pretty simple, we have an EditText to get the file name, A button to upload the file and a TextView to go to the View Upload screen.

View Uploads Screen

As I told you that we have two screens in this app so create one more empty activity and name it ViewUploadsActivity.

Now come inside the layout file for this activity and write the following xml code.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="net.simplifiedlearning.firebasestorage.ViewUploadsActivity"> <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="wrap_content" /> </RelativeLayout>

Creating Helper Classes

For this we need some helper classes for modeling the data and storing the constants. So first create a class named Constants.java and write the following code.

package net.simplifiedlearning.firebasestorage; /** * Created by Belal on 8/25/2017. */ public class Constants public static final String STORAGE_PATH_UPLOADS = "uploads/"; public static final String DATABASE_PATH_UPLOADS = "uploads";

Now to save the uploads data in Firebase database we need a model class. So create a new class named Upload.java and write the following code.

package net.simplifiedlearning.firebasestorage; /** * Created by Belal on 8/25/2017. */ public class Upload public String name; public String url; // Default constructor required for calls to // DataSnapshot.getValue(User.class) public Upload() public Upload(String name, String url) this.name = name; this.url = url; public String getName() return name; public String getUrl() return url;

Now lets upload the files.

Uploading PDF in Firebase Storage

Now here comes the main task of this post which is uploading PDF files to the storage. The uploading is done on the MainActivity so come inside MainActivity.java and write the following code.

package net.simplifiedlearning.firebasestorage; import android.Manifest; import android.content.Intent; import android.content.pm.PackageManager; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.provider.Settings; import android.support.annotation.NonNull; import android.support.v4.content.ContextCompat; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.EditText; import android.widget.ProgressBar; import android.widget.TextView; import android.widget.Toast; import com.google.android.gms.tasks.OnFailureListener; import com.google.android.gms.tasks.OnSuccessListener; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; 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 MainActivity extends AppCompatActivity implements View.OnClickListener //this is the pic pdf code used in file chooser final static int PICK_PDF_CODE = 2342; //these are the views TextView textViewStatus; EditText editTextFilename; ProgressBar progressBar; //the firebase objects for storage and database StorageReference mStorageReference; DatabaseReference mDatabaseReference; @Override protected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //getting firebase objects mStorageReference = FirebaseStorage.getInstance().getReference(); mDatabaseReference = FirebaseDatabase.getInstance().getReference(Constants.DATABASE_PATH_UPLOADS); //getting the views textViewStatus = (TextView) findViewById(R.id.textViewStatus); editTextFilename = (EditText) findViewById(R.id.editTextFileName); progressBar = (ProgressBar) findViewById(R.id.progressbar); //attaching listeners to views findViewById(R.id.buttonUploadFile).setOnClickListener(this); findViewById(R.id.textViewUploads).setOnClickListener(this); //this function will get the pdf from the storage private void getPDF() //for greater than lolipop versions we need the permissions asked on runtime //so if the permission is not available user will go to the screen to allow storage permission if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.parse("package:" + getPackageName())); startActivity(intent); return; //creating an intent for file chooser Intent intent = new Intent(); intent.setType("application/pdf"); intent.setAction(Intent.ACTION_GET_CONTENT); startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_PDF_CODE); @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) super.onActivityResult(requestCode, resultCode, data); //when the user choses the file if (requestCode == PICK_PDF_CODE && resultCode == RESULT_OK && data != null && data.getData() != null) //if a file is selected if (data.getData() != null) //uploading the file uploadFile(data.getData()); else Toast.makeText(this, "No file chosen", Toast.LENGTH_SHORT).show(); //this method is uploading the file //the code is same as the previous tutorial //so we are not explaining it private void uploadFile(Uri data) progressBar.setVisibility(View.VISIBLE); StorageReference sRef = mStorageReference.child(Constants.STORAGE_PATH_UPLOADS + System.currentTimeMillis() + ".pdf"); sRef.putFile(data) .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() @SuppressWarnings("VisibleForTests") @Override public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) progressBar.setVisibility(View.GONE); textViewStatus.setText("File Uploaded Successfully"); Upload upload = new Upload(editTextFilename.getText().toString(), taskSnapshot.getDownloadUrl().toString()); mDatabaseReference.child(mDatabaseReference.push().getKey()).setValue(upload); ) .addOnFailureListener(new OnFailureListener() @Override public void onFailure(@NonNull Exception exception) Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show(); ) .addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() @SuppressWarnings("VisibleForTests") @Override public void onProgress(UploadTask.TaskSnapshot taskSnapshot) double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount(); textViewStatus.setText((int) progress + "% Uploading..."); ); @Override public void onClick(View view) switch (view.getId()) case R.id.buttonUploadFile: getPDF(); break; case R.id.textViewUploads: startActivity(new Intent(this, ViewUploadsActivity.class)); break;

Now you can test uploading a File. But before we need to change the Storage Rules and Database Rules on Firebase Console. As the default rules allows only authenticated users to upload the file and write to the database. So either you need to make an authentication on the app or change the rules to public. So for this example we will make the rules as public.

Changing Firebase Storage and Database Rules

Firebase Storage Rules

Go to Firebase Storage and in Firebase Console and change the rules as below.

service firebase.storage match /b/bucket/o match /allPaths=** allow read, write;

Firebase Database Rules

Now for the Database Rules use the following.

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

Testing the Upload

Now lets test the application by uploading a file.

Uploading PDF in Firebase Storage

Retrieving Files from Firebase Storage

Now come to the ViewUploadsActivity.java and write the following code.

package net.simplifiedlearning.firebasestorage; import android.content.Intent; import android.net.Uri; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.ListView; import com.google.firebase.database.DataSnapshot; import com.google.firebase.database.DatabaseError; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; import com.google.firebase.database.ValueEventListener; import java.util.ArrayList; import java.util.List; public class ViewUploadsActivity extends AppCompatActivity //the listview ListView listView; //database reference to get uploads data DatabaseReference mDatabaseReference; //list to store uploads data List<Upload> uploadList; @Override protected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.activity_view_uploads); uploadList = new ArrayList<>(); listView = (ListView) findViewById(R.id.listView); //adding a clicklistener on listview listView.setOnItemClickListener(new AdapterView.OnItemClickListener() @Override public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) //getting the upload Upload upload = uploadList.get(i); //Opening the upload file in browser using the upload url Intent intent = new Intent(Intent.ACTION_VIEW); intent.setData(Uri.parse(upload.getUrl())); startActivity(intent); ); //getting the database reference mDatabaseReference = FirebaseDatabase.getInstance().getReference(Constants.DATABASE_PATH_UPLOADS); //retrieving upload data from firebase database mDatabaseReference.addValueEventListener(new ValueEventListener() @Override public void onDataChange(DataSnapshot dataSnapshot) for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) Upload upload = postSnapshot.getValue(Upload.class); uploadList.add(upload); String[] uploads = new String[uploadList.size()]; for (int i = 0; i < uploads.length; i++) uploads[i] = uploadList.get(i).getName(); //displaying it to list ArrayAdapter<String> adapter = new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1, uploads); listView.setAdapter(adapter); @Override public void onCancelled(DatabaseError databaseError) );

Now test this screen as well.

Bingo! it is working as well. When you will click on an Item it will download the uploaded file from the storage.

Download Source Code

If you are facing any troubles you can get my source code from here.

Firebase Storage – Upload and Download PDFs Source Code

So thats all for this tutorial friends. If you are having any queries regarding Firebase Storage or Android Development don’t hesitate to comment. And if you want some help if you are stuck in your app then also comment here and I will try to post a tutorial to help you.

New Post has been published on https://www.simplifiedcoding.net/firebase-storage-example/

Firebase Storage Example - Uploading and Retrieving Files

In a previous tutorial we learnt about Firebase Storage. But I didn’t cover retrieval of the uploaded files from Firebase Storage. So here is another Firebase Storage Example. In this tutorial we will learn Uploading Files to Firebase Storage and Retrieving Uploaded Files from Firebase Storage. So lets start this Firebase Storage Example.

Contents

1 Firebase Storage Example Video Demo

2 Firebase Storage Example

2.1 Creating a New Project

2.2 Setting Up Firebase Storage and Firebase Database

2.3 Creating Layout

2.4 Defining Firebase Constants

2.5 Defining View Objects and Constants

2.6 Adding File Chooser

2.7 Uploading File to Firebase Storage and Saving URL to Firebase Database

2.7.1 Building Database Model

2.7.2 Getting Selected File Extension

2.8 Uploading the File to Firebase Storage

2.9 Retrieving Files from Firebase Storage

2.9.1 Adding RecyclerView and CardView

2.9.2 Adding Glide

2.9.3 Creating RecyclerView Layout

2.9.4 Creating RecyclerView Adapter

Firebase Storage Example Video Demo

You can watch this video to know what we are going to build in this tutorial.

Firebase Storage Example

As always the first step is creating a new Android Studio Project.

Creating a New Project

I have just created a project named FirebaseUpload.

In the project we will be uploading images to Firebase Storage and then we will fetch back the uploaded images to display them into RecyclerView.

So now we will setup firebase storage to our project.

Setting Up Firebase Storage and Firebase Database

We will upload the images to Firebase Storage and in the Firebase Database we will store the image URL. For this we need to setup both in our project.

Go to tools -> firebase

Now you will see an Assistant Window, you can setup Firebase Database from here.

Firebase Database

The same way you can setup Firebase Storage.

If you are confused about this step go through the last Firebase Storage Tutorial where I explained it in detail.

Creating Layout

Now we need to build the following layout for activity_main.xml.

activity_main.xml

We have the following components in the above layout. Choose Button: We will tap this button to choose an image from the gallery. EditText Enter Name: In this EditText we will put the label for the chosen image. ImageView: The middle area (you cann’t see it in the layout because it is blank ImageView) contains an ImageView where we will display the chosen image. Upload Button: Tapping this button will upload the selected image to Firebase Storage. TextView Uploads: Tapping this TextView will open another activity where we will display the uploaded images with labels.

You can use the following xml code to build the above layout.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="net.simplifiedcoding.firebaseupload.MainActivity"> <LinearLayout android:id="@+id/linearLayout" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal"> <Button android:id="@+id/buttonChoose" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:text="Choose" /> <EditText android:id="@+id/editText" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="4" android:hint="Enter name for Image" /> </LinearLayout> <ImageView android:id="@+id/imageView" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentLeft="true" android:layout_alignParentStart="true" android:layout_below="@+id/linearLayout" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentBottom="true" android:orientation="vertical"> <Button android:id="@+id/buttonUpload" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_weight="1" android:text="Upload" /> <TextView android:id="@+id/textViewShow" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="10dp" android:text="View Uploads" android:textAlignment="center" android:textColor="@color/colorPrimary" android:textStyle="bold" /> </LinearLayout> </RelativeLayout>

Defining Firebase Constants

Create a java class named Constants.java and define the following.

package net.simplifiedcoding.firebaseupload; /** * Created by Belal on 2/23/2017. */ public class Constants public static final String STORAGE_PATH_UPLOADS = "uploads/"; public static final String DATABASE_PATH_UPLOADS = "uploads";

Defining View Objects and Constants

Come inside MainActivity.java and define the following objects and constants.

public class MainActivity extends AppCompatActivity implements View.OnClickListener{ //constant to track image chooser intent private static final int PICK_IMAGE_REQUEST = 234; //view objects private Button buttonChoose; private Button buttonUpload; private EditText editTextName; private TextView textViewShow; private ImageView imageView; //uri to store file private Uri filePath; //firebase objects private StorageReference storageReference; private DatabaseReference mDatabase;

Now inside onCreate() we will initialize the the objects and attach click listeners.

@Override protected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); buttonChoose = (Button) findViewById(R.id.buttonChoose); buttonUpload = (Button) findViewById(R.id.buttonUpload); imageView = (ImageView) findViewById(R.id.imageView); editTextName = (EditText) findViewById(R.id.editText); textViewShow = (TextView) findViewById(R.id.textViewShow); storageReference = FirebaseStorage.getInstance().getReference(); mDatabase = FirebaseDatabase.getInstance().getReference(Constants.DATABASE_PATH_UPLOADS); buttonChoose.setOnClickListener(this); buttonUpload.setOnClickListener(this); textViewShow.setOnClickListener(this);

Adding File Chooser

Define a new method showFileChooser().

private void showFileChooser() Intent intent = new Intent(); intent.setType("image/*"); intent.setAction(Intent.ACTION_GET_CONTENT); startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE_REQUEST);

Now we need to handle the Intent result. For this we will override the method onActivityResult().

@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) super.onActivityResult(requestCode, resultCode, data); if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null) filePath = data.getData(); try Bitmap bitmap = MediaStore.Images.Media.getBitmap(getContentResolver(), filePath); imageView.setImageBitmap(bitmap); catch (IOException e) e.printStackTrace();

Now we will call the method showFileChooser() when the choose image button is clicked. For this come inside the overriden method onClick() and write the following code.

@Override public void onClick(View view) if (view == buttonChoose) showFileChooser(); else if (view == buttonUpload) else if (view == textViewShow)

Now try running the application and you will see that choose image is working fine.

Now we will code the upload functionality.

Uploading File to Firebase Storage and Saving URL to Firebase Database

Building Database Model

First we will create a class to store the Image data to Firebase Database. So create a class named Upload.java.

package net.simplifiedcoding.firebaseupload; import com.google.firebase.database.IgnoreExtraProperties; /** * Created by Belal on 2/23/2017. */ @IgnoreExtraProperties public class Upload public String name; public String url; // Default constructor required for calls to // DataSnapshot.getValue(User.class) public Upload() public Upload(String name, String url) this.name = name; this.url= url; public String getName() return name; public String getUrl() return url;

Getting Selected File Extension

We will rename the file to a unique name as if we upload the file with same name then files would be overwritten. So after renaming the file the extension should remain the same. So inside MainActivity.java create a method getFileExtension() and it will return as the extension of the selected file by taking Uri object.

public String getFileExtension(Uri uri) ContentResolver cR = getContentResolver(); MimeTypeMap mime = MimeTypeMap.getSingleton(); return mime.getExtensionFromMimeType(cR.getType(uri));

Uploading the File to Firebase Storage

Now we will create a method inside MainActivity.java that will upload the selected file to Firebase Storage. So create a method name uploadFile() and write the following code.

private void uploadFile() //checking if file is available if (filePath != null) //displaying progress dialog while image is uploading final ProgressDialog progressDialog = new ProgressDialog(this); progressDialog.setTitle("Uploading"); progressDialog.show(); //getting the storage reference StorageReference sRef = storageReference.child(Constants.STORAGE_PATH_UPLOADS + System.currentTimeMillis() + "." + getFileExtension(filePath)); //adding the file to reference sRef.putFile(filePath) .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() @Override public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) //dismissing the progress dialog progressDialog.dismiss(); //displaying success toast Toast.makeText(getApplicationContext(), "File Uploaded ", Toast.LENGTH_LONG).show(); //creating the upload object to store uploaded image details Upload upload = new Upload(editTextName.getText().toString().trim(), taskSnapshot.getDownloadUrl().toString()); //adding an upload to firebase database String uploadId = mDatabase.push().getKey(); mDatabase.child(uploadId).setValue(upload); ) .addOnFailureListener(new OnFailureListener() @Override public void onFailure(@NonNull Exception exception) progressDialog.dismiss(); Toast.makeText(getApplicationContext(), exception.getMessage(), Toast.LENGTH_LONG).show(); ) .addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() @Override public void onProgress(UploadTask.TaskSnapshot taskSnapshot) //displaying the upload progress double progress = (100.0 * taskSnapshot.getBytesTransferred()) / taskSnapshot.getTotalByteCount(); progressDialog.setMessage("Uploaded " + ((int) progress) + "%..."); ); else //display an error if no file is selected

Now we need to call this method on Upload Button Click. So modify onClick() method as below.

@Override public void onClick(View view) if (view == buttonChoose) showFileChooser(); else if (view == buttonUpload) uploadFile(); else if (view == textViewShow)

Now try running your application and upload will work.

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Retrieving Files from Firebase Storage

Now we will create a new activity where we display all the uploaded images with labels.

So create a new activity named ShowImagesActivity and inside the layout file of this activity we will create a RecyclerView.

Adding RecyclerView and CardView

First we need to add dependencies for RecyclerView and CardView.

Go to File -> Project Structure and go to dependencies tab. Here click on plus icon and select Library dependency.

Now here you need to find and add RecyclerView and CardView.

Now sync your project.

Adding Glide

We also need to add Glide Library. As we need to fetch images from the URL and for this I will be using Glide Library.

So just modify  dependencies block of your app level build.gradle file as below.

dependencies compile fileTree(include: ['*.jar'], dir: 'libs') androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', exclude group: 'com.android.support', module: 'support-annotations' ) compile 'com.android.support:appcompat-v7:25.2.0' compile 'com.google.firebase:firebase-storage:10.2.0' compile 'com.google.firebase:firebase-auth:10.2.0' compile 'com.google.firebase:firebase-database:10.2.0' testCompile 'junit:junit:4.12' compile 'com.android.support:recyclerview-v7:25.2.0' compile 'com.android.support:cardview-v7:25.2.0' //adding glid library compile 'com.github.bumptech.glide:glide:3.7.0'

Now sync the project with gradle.

Creating RecyclerView Layout

Now we will design the layout for our RecyclerView. It will contain an ImageView and a TextView inside a CardView. So create a new layout resource file named layout_images.xml.

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <android.support.v7.widget.CardView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_margin="8dp" android:padding="8dp"> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="100dp"> <TextView android:id="@+id/textViewName" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="Name" android:textAlignment="center" /> <ImageView android:id="@+id/imageView" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/textViewName" /> </RelativeLayout> </android.support.v7.widget.CardView> </LinearLayout>

So our layout for RecyclerView is ready. Now we will create an Adapter.

Creating RecyclerView Adapter

Create a class named MyAdapter.java and write the following code.

package net.simplifiedcoding.firebaseupload; import android.content.Context; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ImageView; import android.widget.TextView; import com.bumptech.glide.Glide; import java.util.List; /** * Created by Belal on 2/23/2017. */ public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> private Context context; private List<Upload> uploads; public MyAdapter(Context context, List<Upload> uploads) this.uploads = uploads; this.context = context; @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) View v = LayoutInflater.from(parent.getContext()) .inflate(R.layout.layout_images, parent, false); ViewHolder viewHolder = new ViewHolder(v); return viewHolder; @Override public void onBindViewHolder(ViewHolder holder, int position) Upload upload = uploads.get(position); holder.textViewName.setText(upload.getName()); Glide.with(context).load(upload.getUrl()).into(holder.imageView); @Override public int getItemCount() return uploads.size(); class ViewHolder extends RecyclerView.ViewHolder public TextView textViewName; public ImageView imageView; public ViewHolder(View itemView) super(itemView); textViewName = (TextView) itemView.findViewById(R.id.textViewName); imageView = (ImageView) itemView.findViewById(R.id.imageView);

Now come inside layout file of this ShowImagesActivity and add a RecyclerView.

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_show_images" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="net.simplifiedcoding.firebaseupload.ShowImagesActivity"> <android.support.v7.widget.RecyclerView android:id="@+id/recyclerView" android:layout_width="match_parent" android:layout_height="wrap_content"> </android.support.v7.widget.RecyclerView> </RelativeLayout>

Now write the following code inside ShowImagesActivity.java

package net.simplifiedcoding.firebaseupload; import android.app.ProgressDialog; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.util.Log; import android.widget.Toast; import com.google.firebase.database.DataSnapshot; import com.google.firebase.database.DatabaseError; import com.google.firebase.database.DatabaseReference; import com.google.firebase.database.FirebaseDatabase; import com.google.firebase.database.ValueEventListener; import java.util.ArrayList; import java.util.List; public class ShowImagesActivity extends AppCompatActivity //recyclerview object private RecyclerView recyclerView; //adapter object private RecyclerView.Adapter adapter; //database reference private DatabaseReference mDatabase; //progress dialog private ProgressDialog progressDialog; //list to hold all the uploaded images private List<Upload> uploads; @Override protected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState); setContentView(R.layout.activity_show_images); recyclerView = (RecyclerView) findViewById(R.id.recyclerView); recyclerView.setHasFixedSize(true); recyclerView.setLayoutManager(new LinearLayoutManager(this)); progressDialog = new ProgressDialog(this); uploads = new ArrayList<>(); //displaying progress dialog while fetching images progressDialog.setMessage("Please wait..."); progressDialog.show(); mDatabase = FirebaseDatabase.getInstance().getReference(Constants.DATABASE_PATH_UPLOADS); //adding an event listener to fetch values mDatabase.addValueEventListener(new ValueEventListener() @Override public void onDataChange(DataSnapshot snapshot) //dismissing the progress dialog progressDialog.dismiss(); //iterating through all the values in database for (DataSnapshot postSnapshot : snapshot.getChildren()) Upload upload = postSnapshot.getValue(Upload.class); uploads.add(upload); //creating adapter adapter = new MyAdapter(getApplicationContext(), uploads); //adding adapter to recyclerview recyclerView.setAdapter(adapter); @Override public void onCancelled(DatabaseError databaseError) progressDialog.dismiss(); );

Thats it now just run your application and you will see all the fetched images in the next activity.

Bingo! Its working absolutely fine.  Now if you are having troubles or confusions you can get my source code from the link given below.

Firebase Storage Example Source Code Download